Bump the actions-minor group with 2 updates (#400)

Bumps the actions-minor group with 2 updates: [actions/setup-node](https://github.com/actions/setup-node) and [github/codeql-action](https://github.com/github/codeql-action).


Updates `actions/setup-node` from 6.3.0 to 6.4.0
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](53b83947a5...48b55a011b)

Updates `github/codeql-action` from 4.35.1 to 4.35.2
- [Release notes](https://github.com/github/codeql-action/releases)
- [Changelog](https://github.com/github/codeql-action/blob/main/CHANGELOG.md)
- [Commits](c10b8064de...95e58e9a2c)

---
updated-dependencies:
- dependency-name: actions/setup-node
  dependency-version: 6.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: actions-minor
- dependency-name: github/codeql-action
  dependency-version: 4.35.2
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: actions-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/check-dist.yml

@@ -28,11 +28,11 @@ jobs:
     steps:
       - name: Checkout
         id: checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Setup Node.js
         id: setup-node
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         with:
           node-version-file: .node-version
           cache: npm
@@ -60,7 +60,7 @@ jobs:
       - if: ${{ failure() && steps.diff.outcome == 'failure' }}
         name: Upload Artifact
         id: upload
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
         with:
           name: dist
           path: dist/

.github/workflows/ci.yml

@@ -21,11 +21,11 @@ jobs:
     steps:
       - name: Checkout
         id: checkout
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        uses: actions/checkout@0c366fd6a839edf440554fa01a7085ccba70ac98 # v5.0.1
 
       - name: Setup Node.js
         id: setup-node
-        uses: actions/setup-node@b39b52d1213e96004bfcb1c61a8a6fa8ab84f3e8 # v4.0.1
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         with:
           node-version-file: .node-version
           cache: npm
@@ -58,7 +58,7 @@ jobs:
     steps:
       - name: Checkout
         id: checkout
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        uses: actions/checkout@0c366fd6a839edf440554fa01a7085ccba70ac98 # v5.0.1
       - name: Calculate subject digest
         id: subject
         env:

.github/workflows/codeql-analysis.yml

@@ -32,19 +32,19 @@ jobs:
     steps:
       - name: Checkout
         id: checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Initialize CodeQL
         id: initialize
-        uses: github/codeql-action/init@v3
+        uses: github/codeql-action/init@95e58e9a2cdfd71adc6e0353d5c52f41a045d225 # v4.35.2
         with:
           languages: ${{ matrix.language }}
           source-root: src
 
       - name: Autobuild
         id: autobuild
-        uses: github/codeql-action/autobuild@v3
+        uses: github/codeql-action/autobuild@95e58e9a2cdfd71adc6e0353d5c52f41a045d225 # v4.35.2
 
       - name: Perform CodeQL Analysis
         id: analyze
-        uses: github/codeql-action/analyze@v3
+        uses: github/codeql-action/analyze@95e58e9a2cdfd71adc6e0353d5c52f41a045d225 # v4.35.2

.github/workflows/prober-github.yml

@@ -0,0 +1,18 @@
+name: GitHub Sigstore Prober
+
+on:
+  workflow_dispatch:
+  schedule:
+    # run every 5 minutes, as often as Github Actions allows
+    - cron: '*/5 * * * *'
+
+jobs:
+  prober:
+    if: github.repository_owner == 'actions'
+    permissions:
+      attestations: write
+      id-token: write
+    secrets: inherit
+    uses: ./.github/workflows/prober.yml
+    with:
+      sigstore: github

.github/workflows/prober-public-good.yml

@@ -0,0 +1,18 @@
+name: Public-Good Sigstore Prober
+
+on:
+  workflow_dispatch:
+  schedule:
+    # run every 5 minutes, as often as Github Actions allows
+    - cron: '*/5 * * * *'
+
+jobs:
+  prober:
+    if: github.repository_owner == 'actions'
+    permissions:
+      attestations: write
+      id-token: write
+    secrets: inherit
+    uses: ./.github/workflows/prober.yml
+    with:
+      sigstore: public-good

.github/workflows/prober.yml

@@ -0,0 +1,84 @@
+name: Prober Workflow
+
+on:
+  workflow_call:
+    inputs:
+      sigstore:
+        description: 'Which Sigstore instance to use for signing'
+        required: true
+        type: string
+
+jobs:
+  probe:
+    runs-on: ubuntu-latest
+    permissions:
+      attestations: write
+      id-token: write
+
+    steps:
+      - name: Request OIDC Token
+        run: |
+          curl "${ACTIONS_ID_TOKEN_REQUEST_URL}&audience=nobody" \
+            -H "Authorization: bearer ${ACTIONS_ID_TOKEN_REQUEST_TOKEN}" \
+            -H "Accept: application/json; api-version=2.0" \
+            -H "Content-Type: application/json" \
+            --silent | jq -r '.value' | jq -R 'split(".") | .[0],.[1] | @base64d | fromjson'
+
+      - name: Create artifact
+        run: |
+          date > artifact
+
+      - name: Attest build provenance
+        uses: actions/attest@main
+        env:
+          INPUT_PRIVATE-SIGNING: ${{ inputs.sigstore == 'github' && 'true' || 'false' }}
+        with:
+          subject-path: artifact
+
+      - name: Verify build artifact
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh attestation verify ./artifact --owner "$GITHUB_REPOSITORY_OWNER"
+
+      - name: Upload build artifact
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          path: "artifact"
+
+      - name: Report attestation prober success
+        if: ${{ success() }}
+        uses: masci/datadog@d7cb6cfc2ba13f7c2ae5227a26f2e2f42a7d179e # v2.0.2
+        with:
+          api-key: "${{ secrets.DATADOG_API_KEY }}"
+          service-checks: |
+            - check: "attestation-integration.actions.prober"
+              status: 0
+              host_name: github.com
+              tags:
+                - "catalog_service:${{ secrets.CATALOG_SERVICE }}"
+                - "service:${{ secrets.CATALOG_SERVICE }}"
+                - "stamp:${{ secrets.STAMP }}"
+                - "env:production"
+                - "repo:${{ github.repository }}"
+                - "team:${{ secrets.TEAM }}"
+                - "sigstore:${{ inputs.sigstore }}"
+
+      - name: Report attestation prober failure
+        if: ${{ failure() }}
+        uses: masci/datadog@d7cb6cfc2ba13f7c2ae5227a26f2e2f42a7d179e # v2.0.2
+        with:
+          api-key: "${{ secrets.DATADOG_API_KEY }}"
+          service-checks: |
+            - check: "attestation-integration.actions.prober"
+              message: "${{ github.repository_owner }} failed prober check"
+              status: 2
+              host_name: github.com
+              tags:
+                - "catalog_service:${{ secrets.CATALOG_SERVICE }}"
+                - "service:${{ secrets.CATALOG_SERVICE }}"
+                - "stamp:${{ secrets.STAMP }}"
+                - "env:production"
+                - "repo:${{ github.repository }}"
+                - "team:${{ secrets.TEAM }}"
+                - "sigstore:${{ inputs.sigstore }}"

README.md

@@ -41,6 +41,21 @@ information on artifact attestations.
 > Artifact attestations are NOT supported on GitHub Enterprise Server.
 <!-- prettier-ignore-end -->
 
+## Attestation Modes
+
+This action supports three attestation modes, automatically detected based on
+the inputs you provide:
+
+<!-- markdownlint-disable MD013 -->
+
+| Mode           | When Used                                              | Description                                     |
+| -------------- | ------------------------------------------------------ | ----------------------------------------------- |
+| **Provenance** | No `sbom-path` or predicate inputs                     | Auto-generates [SLSA build provenance][10]      |
+| **SBOM**       | `sbom-path` is provided                                | Creates attestation from SPDX or CycloneDX SBOM |
+| **Custom**     | `predicate-type`/`predicate`/`predicate-path` provided | User-supplied predicate                         |
+
+<!-- markdownlint-enable MD013 -->
+
 ## Usage
 
 Within the GitHub Actions workflow which builds some artifact you would like to
@@ -52,33 +67,32 @@ attest:
    permissions:
      id-token: write
      attestations: write
+     artifact-metadata: write
    ```
 
    The `id-token` permission gives the action the ability to mint the OIDC token
    necessary to request a Sigstore signing certificate. The `attestations`
-   permission is necessary to persist the attestation.
+   permission is necessary to persist the attestation. The `artifact-metadata`
+   permission is necessary to create the artifact storage record.
 
 1. Add the following to your workflow after your artifact has been built:
 
    ```yaml
-   - uses: actions/attest@v2
+   - uses: actions/attest@v4
      with:
        subject-path: '<PATH TO ARTIFACT>'
-       predicate-type: '<PREDICATE URI>'
-       predicate-path: '<PATH TO PREDICATE>'
    ```
 
-   The `subject-path` parameter should identify the artifact for which you want
+   By default, this generates a [SLSA build provenance][10] attestation. For
-   to generate an attestation. The `predicate-type` can be any of the the
+   SBOM or custom attestations, see the [Attestation Modes](#attestation-modes)
-   [vetted predicate types][3] or a custom value. The `predicate-path`
+   section.
-   identifies a file containing the JSON-encoded predicate parameters.
 
 ### Inputs
 
 See [action.yml](action.yml)
 
 ```yaml
-- uses: actions/attest@v2
+- uses: actions/attest@v4
   with:
     # Path to the artifact serving as the subject of the attestation. Must
     # specify exactly one of "subject-path", "subject-digest", or
@@ -100,17 +114,24 @@ See [action.yml](action.yml)
     # or "subject-checksums".
     subject-checksums:
 
-    # URI identifying the type of the predicate.
+    # Path to the JSON-formatted SBOM file (SPDX or CycloneDX) to attest.
+    # File size cannot exceed 16MB. When provided, creates an SBOM attestation.
+    # Cannot be used together with "predicate-type", "predicate", or
+    # "predicate-path".
+    sbom-path:
+
+    # URI identifying the type of the predicate. Required when using "predicate"
+    # or "predicate-path" for custom attestations.
     predicate-type:
 
     # String containing the value for the attestation predicate. String length
     # cannot exceed 16MB. Must supply exactly one of "predicate-path" or
-    # "predicate".
+    # "predicate" when creating custom attestations.
     predicate:
 
     # Path to the file which contains the content for the attestation predicate.
     # File size cannot exceed 16MB. Must supply exactly one of "predicate-path"
-    # or "predicate".
+    # or "predicate" when creating custom attestations.
     predicate-path:
 
     # Whether to push the attestation to the image registry. Requires that the
@@ -118,6 +139,12 @@ See [action.yml](action.yml)
     # the "subject-digest" parameter be specified. Defaults to false.
     push-to-registry:
 
+    # Whether to create a storage record for the artifact.
+    # Requires that push-to-registry is set to true.
+    # Requires that the "subject-name" parameter specify the fully-qualified
+    # image name. Defaults to true.
+    create-storage-record:
+
     # Whether to attach a list of generated attestations to the workflow run
     # summary page. Defaults to true.
     show-summary:
@@ -131,11 +158,12 @@ See [action.yml](action.yml)
 
 <!-- markdownlint-disable MD013 -->
 
-| Name              | Description                                                    | Example                                          |
+| Name                 | Description                                                    | Example                                          |
-| ----------------- | -------------------------------------------------------------- | ------------------------------------------------ |
+| -------------------- | -------------------------------------------------------------- | ------------------------------------------------ |
-| `attestation-id`  | GitHub ID for the attestation                                  | `123456`                                         |
+| `attestation-id`     | GitHub ID for the attestation                                  | `123456`                                         |
-| `attestation-url` | URL for the attestation summary                                | `https://github.com/foo/bar/attestations/123456` |
+| `attestation-url`    | URL for the attestation summary                                | `https://github.com/foo/bar/attestations/123456` |
-| `bundle-path`     | Absolute path to the file containing the generated attestation | `/tmp/attestation.json`                          |
+| `bundle-path`        | Absolute path to the file containing the generated attestation | `/tmp/attestation.json`                          |
+| `storage-record-ids` | GitHub IDs for the storage records                             | `987654`                                         |
 
 <!-- markdownlint-enable MD013 -->
 
@@ -157,13 +185,13 @@ string cannot exceed 16MB.
 
 ## Examples
 
-### Identify Subject by Path
+### Provenance Attestation (Default)
 
-For the basic use case, simply add the `attest` action to your workflow and
+The simplest use case - just specify the artifact path and a SLSA build
-supply the path to the artifact for which you want to generate attestation.
+provenance attestation is automatically generated:
 
 ```yaml
-name: build-attest
+name: build-attest-provenance
 
 on:
   workflow_dispatch:
@@ -181,11 +209,36 @@ jobs:
       - name: Build artifact
         run: make my-app
       - name: Attest
-        uses: actions/attest@v2
+        uses: actions/attest@v4
         with:
           subject-path: '${{ github.workspace }}/my-app'
-          predicate-type: 'https://example.com/predicate/v1'
+```
-          predicate: '{}'
+
+### SBOM Attestation
+
+To create an SBOM attestation, provide the path to an SPDX or CycloneDX JSON
+file:
+
+```yaml
+- name: Generate SBOM
+  run: syft . -o spdx-json > sbom.spdx.json
+
+- uses: actions/attest@v4
+  with:
+    subject-path: '${{ github.workspace }}/my-app'
+    sbom-path: '${{ github.workspace }}/sbom.spdx.json'
+```
+
+### Custom Attestation
+
+For custom attestations, provide your own predicate type and content:
+
+```yaml
+- uses: actions/attest@v4
+  with:
+    subject-path: '${{ github.workspace }}/my-app'
+    predicate-type: 'https://example.com/predicate/v1'
+    predicate: '{}'
 ```
 
 ### Identify Multiple Subjects
@@ -194,7 +247,7 @@ If you are generating multiple artifacts, you can attest all of them at the same
 time by using a wildcard in the `subject-path` input.
 
 ```yaml
-- uses: actions/attest@v2
+- uses: actions/attest@v4
   with:
     subject-path: 'dist/**/my-bin-*'
     predicate-type: 'https://example.com/predicate/v1'
@@ -208,13 +261,13 @@ Alternatively, you can explicitly list multiple subjects with either a comma or
 newline delimited list:
 
 ```yaml
-- uses: actions/attest@v2
+- uses: actions/attest@v4
   with:
     subject-path: 'dist/foo, dist/bar'
 ```
 
 ```yaml
-- uses: actions/attest@v2
+- uses: actions/attest@v4
   with:
     subject-path: |
       dist/foo
@@ -236,11 +289,9 @@ attestation.
   run: |
     shasum -a 256 foo_0.0.1_* > subject.checksums.txt
 
-- uses: actions/attest@v2
+- uses: actions/attest@v4
   with:
     subject-checksums: subject.checksums.txt
-    predicate-type: 'https://example.com/predicate/v1'
-    predicate: '{}'
 ```
 
 <!-- markdownlint-disable MD038 -->
@@ -269,6 +320,26 @@ fully-qualified image name (e.g. "ghcr.io/user/app" or
 "acme.azurecr.io/user/app"). Do NOT include a tag as part of the image name --
 the specific image being attested is identified by the supplied digest.
 
+#### Artifact Metadata Storage Records
+
+When generating a build provenance attestation, if the `push-to-registry` option
+is set to true, the Action will also emit an
+[Artifact Metadata Storage Record](https://docs.github.com/en/rest/orgs/artifact-metadata?apiVersion=2022-11-28#create-artifact-metadata-storage-record).
+Storage records enrich artifact metadata by capturing storage related details,
+such as which registry an image is hosted on and whether it's marked as active.
+
+If you do not want to emit a storage record, set `create-storage-record` to
+`false`.
+
+> **NOTE**: Storage records can only be created for artifacts built from
+> [organization-owned](https://docs.github.com/en/organizations/collaborating-with-groups-in-organizations/about-organizations)
+> repositories.
+
+Artifacts associated with a storage record can be viewed by navigating to the
+`Linked Artifacts` page in your organization:
+`https://github.com/orgs/YOUR_ORG/artifacts` (replace `YOUR_ORG` with your
+organization name).
+
 > **NOTE**: When pushing to Docker Hub, please use "docker.io" as the registry
 > portion of the image name.
 
@@ -287,6 +358,7 @@ jobs:
       packages: write
       contents: read
       attestations: write
+      artifact-metadata: write
     env:
       REGISTRY: ghcr.io
       IMAGE_NAME: ${{ github.repository }}
@@ -308,13 +380,11 @@ jobs:
           push: true
           tags: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest
       - name: Attest
-        uses: actions/attest@v2
+        uses: actions/attest@v4
         id: attest
         with:
           subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           subject-digest: ${{ steps.push.outputs.digest }}
-          predicate-type: 'https://in-toto.io/attestation/release/v0.1'
-          predicate: '{"purl":"pkg:oci/..."}'
           push-to-registry: true
 ```
 
@@ -329,3 +399,4 @@ jobs:
 [8]: https://github.com/actions/toolkit/tree/main/packages/glob#patterns
 [9]:
   https://docs.github.com/en/actions/security-guides/using-artifact-attestations-to-establish-provenance-for-builds
+[10]: https://slsa.dev/spec/v1.0/provenance

__tests__/fixtures/mocks.ts

@@ -0,0 +1,253 @@
+import type { Attestation, Predicate, Subject } from '@actions/attest'
+import { jest } from '@jest/globals'
+import type { RestEndpointMethodTypes } from '@octokit/plugin-rest-endpoint-methods'
+import type { Descriptor } from '@sigstore/oci'
+
+// =============================================================================
+// @actions/core mock factory
+// =============================================================================
+
+export type CoreMock = {
+  info: jest.Mock
+  warning: jest.Mock
+  debug: jest.Mock
+  startGroup: jest.Mock
+  endGroup: jest.Mock
+  setOutput: jest.Mock
+  setFailed: jest.Mock
+  summary: SummaryMock
+}
+
+export type SummaryMock = {
+  write: jest.Mock
+  addRaw: jest.Mock
+  addHeading: jest.Mock
+  addLink: jest.Mock
+  addTable: jest.Mock
+  addBreak: jest.Mock
+  addSeparator: jest.Mock
+  addQuote: jest.Mock
+  addCodeBlock: jest.Mock
+  addList: jest.Mock
+  addImage: jest.Mock
+  addDetails: jest.Mock
+  addEOL: jest.Mock
+  emptyBuffer: jest.Mock
+  stringify: jest.Mock
+  isEmptyBuffer: jest.Mock
+  clear: jest.Mock
+}
+
+export const createSummaryMock = (): SummaryMock => {
+  const mock: SummaryMock = {
+    write: jest.fn(),
+    addRaw: jest.fn(),
+    addHeading: jest.fn(),
+    addLink: jest.fn(),
+    addTable: jest.fn(),
+    addBreak: jest.fn(),
+    addSeparator: jest.fn(),
+    addQuote: jest.fn(),
+    addCodeBlock: jest.fn(),
+    addList: jest.fn(),
+    addImage: jest.fn(),
+    addDetails: jest.fn(),
+    addEOL: jest.fn(),
+    emptyBuffer: jest.fn(),
+    stringify: jest.fn().mockReturnValue(''),
+    isEmptyBuffer: jest.fn().mockReturnValue(true),
+    clear: jest.fn()
+  }
+  // Make chainable
+  for (const key of Object.keys(mock) as (keyof SummaryMock)[]) {
+    if (key !== 'stringify' && key !== 'isEmptyBuffer') {
+      mock[key].mockReturnThis()
+    }
+  }
+  return mock
+}
+
+export const createCoreMock = (): CoreMock => ({
+  info: jest.fn(),
+  warning: jest.fn(),
+  debug: jest.fn(),
+  startGroup: jest.fn(),
+  endGroup: jest.fn(),
+  setOutput: jest.fn(),
+  setFailed: jest.fn(),
+  summary: createSummaryMock()
+})
+
+// =============================================================================
+// @actions/github mock factory
+// =============================================================================
+
+export type GitHubContextMock = {
+  repo: { owner: string; repo: string }
+  payload: { repository?: { visibility: string } }
+  serverUrl: string
+}
+
+export const createGitHubContextMock = (
+  overrides: Partial<GitHubContextMock> = {}
+): GitHubContextMock => ({
+  repo: { owner: 'test-owner', repo: 'test-repo' },
+  payload: { repository: { visibility: 'public' } },
+  serverUrl: 'https://github.com',
+  ...overrides
+})
+
+export type OctokitMock = {
+  rest: {
+    repos: {
+      get: jest.Mock
+    }
+  }
+}
+
+export const createOctokitMock = (
+  ownerType: 'Organization' | 'User' = 'Organization'
+): OctokitMock => ({
+  rest: {
+    repos: {
+      get: jest
+        .fn<RestEndpointMethodTypes['repos']['get']['response']>()
+        .mockResolvedValue({
+          data: { owner: { type: ownerType } }
+        })
+    }
+  }
+})
+
+// =============================================================================
+// @actions/attest mock factory
+// =============================================================================
+
+export type AttestMock = {
+  attest: jest.Mock
+  buildSLSAProvenancePredicate: jest.Mock
+  createStorageRecord: jest.Mock
+}
+
+export const createAttestMock = (): AttestMock => ({
+  attest: jest.fn(),
+  buildSLSAProvenancePredicate: jest.fn(),
+  createStorageRecord: jest.fn()
+})
+
+export const createAttestationResult = (
+  overrides: Partial<Attestation> = {}
+): Attestation => ({
+  bundle: {
+    mediaType: 'application/vnd.dev.sigstore.bundle.v0.3+json' as const,
+    verificationMaterial: {
+      certificate: { rawBytes: '' },
+      publicKey: undefined,
+      x509CertificateChain: undefined,
+      tlogEntries: [],
+      timestampVerificationData: undefined
+    },
+    dsseEnvelope: {
+      payload: '',
+      payloadType: '',
+      signatures: []
+    },
+    messageSignature: undefined
+  },
+  certificate: '-----BEGIN CERTIFICATE-----\ntest\n-----END CERTIFICATE-----',
+  tlogID: 'tlog-123',
+  attestationID: 'att-123',
+  ...overrides
+})
+
+// =============================================================================
+// @sigstore/oci mock factory
+// =============================================================================
+
+export type OciMock = {
+  getRegistryCredentials: jest.Mock
+  attachArtifactToImage: jest.Mock
+}
+
+export const createOciMock = (): OciMock => ({
+  getRegistryCredentials: jest.fn().mockReturnValue({
+    username: 'test-user',
+    password: 'test-pass'
+  }),
+  attachArtifactToImage: jest
+    .fn<() => Promise<Descriptor>>()
+    .mockResolvedValue({
+      digest: 'sha256:abc123def456',
+      mediaType: 'application/vnd.dev.sigstore.bundle.v0.3+json',
+      size: 1234
+    })
+})
+
+// =============================================================================
+// Common test data
+// =============================================================================
+
+export const TEST_SUBJECT: Subject = {
+  name: 'test-artifact',
+  digest: {
+    sha256: '7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
+  }
+}
+
+export const TEST_SUBJECT_WITH_REGISTRY: Subject = {
+  name: 'ghcr.io/test-owner/test-repo',
+  digest: {
+    sha256: '7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
+  }
+}
+
+export const TEST_PREDICATE: Predicate = {
+  type: 'https://example.com/predicate/v1',
+  params: { foo: 'bar' }
+}
+
+export const TEST_PROVENANCE_PREDICATE: Predicate = {
+  type: 'https://slsa.dev/provenance/v1',
+  params: {
+    buildDefinition: {
+      buildType: 'https://actions.github.io/buildtypes/workflow/v1'
+    },
+    runDetails: {
+      builder: { id: 'https://github.com/actions/runner' }
+    }
+  }
+}
+
+// =============================================================================
+// Environment helpers
+// =============================================================================
+
+export const setupTestEnvironment = (
+  env: Record<string, string> = {}
+): (() => void) => {
+  const originalEnv = { ...process.env }
+
+  process.env = {
+    ...process.env,
+    ACTIONS_ID_TOKEN_REQUEST_URL: 'https://token.url',
+    ACTIONS_ID_TOKEN_REQUEST_TOKEN: 'test-token',
+    RUNNER_TEMP: '/tmp',
+    ...env
+  }
+
+  return () => {
+    process.env = originalEnv
+  }
+}
+
+// =============================================================================
+// OIDC token helpers
+// =============================================================================
+
+export const createOidcToken = (subject = 'test@example.com'): string => {
+  const payload = {
+    sub: subject,
+    iss: 'https://token.actions.githubusercontent.com'
+  }
+  return `.${Buffer.from(JSON.stringify(payload)).toString('base64')}.`
+}

__tests__/fixtures/samples/cyclonedx-sbom.json

@@ -0,0 +1,13 @@
+{
+  "bomFormat": "CycloneDX",
+  "specVersion": "1.4",
+  "serialNumber": "urn:uuid:12345678-1234-1234-1234-123456789012",
+  "version": 1,
+  "components": [
+    {
+      "type": "library",
+      "name": "test-component",
+      "version": "1.0.0"
+    }
+  ]
+}

__tests__/fixtures/samples/predicate.json

@@ -0,0 +1,9 @@
+{
+  "buildType": "https://example.com/build/v1",
+  "builder": {
+    "id": "https://github.com/actions/runner"
+  },
+  "metadata": {
+    "buildStartedOn": "2024-01-01T00:00:00Z"
+  }
+}

__tests__/fixtures/samples/spdx-sbom.json

@@ -0,0 +1,15 @@
+{
+  "spdxVersion": "SPDX-2.3",
+  "SPDXID": "SPDXRef-DOCUMENT",
+  "name": "test-package",
+  "dataLicense": "CC0-1.0",
+  "documentNamespace": "https://example.com/test-package",
+  "packages": [
+    {
+      "SPDXID": "SPDXRef-Package",
+      "name": "test-package",
+      "versionInfo": "1.0.0",
+      "downloadLocation": "https://example.com/test-package-1.0.0.tar.gz"
+    }
+  ]
+}

__tests__/index.test.ts

@@ -1,22 +1,73 @@
-/**
+import { jest } from '@jest/globals'
- * Unit tests for the action's entrypoint, src/index.ts
- */
 
-import * as core from '@actions/core'
+// Mock functions
-import * as main from '../src/main'
+const mockRun = jest.fn()
+const mockGetInput = jest.fn()
+const mockGetBooleanInput = jest.fn()
 
-// Mock the action's entrypoint
+// Mock @actions/core
-const runMock = jest.spyOn(main, 'run').mockImplementation()
+jest.unstable_mockModule('@actions/core', () => ({
-const getBooleanInputMock = jest.spyOn(core, 'getBooleanInput')
+  getInput: mockGetInput,
+  getBooleanInput: mockGetBooleanInput
+}))
+
+// Mock ../src/main
+jest.unstable_mockModule('../src/main', () => ({
+  run: mockRun
+}))
 
 describe('index', () => {
   beforeEach(() => {
-    getBooleanInputMock.mockImplementation(() => false)
+    jest.clearAllMocks()
+    mockGetInput.mockReturnValue('')
+    mockGetBooleanInput.mockReturnValue(false)
   })
-  it('calls run when imported', () => {
-    // eslint-disable-next-line @typescript-eslint/no-require-imports
-    require('../src/index')
 
-    expect(runMock).toHaveBeenCalled()
+  it('should call run with inputs from core.getInput', async () => {
+    mockGetInput.mockImplementation((name: string) => {
+      const inputs: Record<string, string> = {
+        'subject-path': '/path/to/subject',
+        'subject-name': 'my-artifact',
+        'subject-digest': '',
+        'subject-checksums': '',
+        'subject-version': '',
+        'predicate-type': 'https://example.com/predicate',
+        predicate: '{}',
+        'predicate-path': '',
+        'sbom-path': '',
+        'github-token': 'test-token'
+      }
+      return inputs[name] || ''
+    })
+
+    mockGetBooleanInput.mockImplementation((name: string) => {
+      const inputs: Record<string, boolean> = {
+        'push-to-registry': false,
+        'create-storage-record': true,
+        'show-summary': true,
+        'private-signing': false
+      }
+      return inputs[name] || false
+    })
+
+    // Dynamic import triggers the module
+    await import('../src/index')
+
+    expect(mockRun).toHaveBeenCalledWith({
+      subjectPath: '/path/to/subject',
+      subjectName: 'my-artifact',
+      subjectDigest: '',
+      subjectChecksums: '',
+      subjectVersion: '',
+      predicateType: 'https://example.com/predicate',
+      predicate: '{}',
+      predicatePath: '',
+      sbomPath: '',
+      githubToken: 'test-token',
+      pushToRegistry: false,
+      createStorageRecord: true,
+      showSummary: true,
+      privateSigning: false
+    })
   })
 })

__tests__/integration/attest.test.ts

@@ -0,0 +1,246 @@
+import { jest } from '@jest/globals'
+import {
+  createAttestationResult,
+  createGitHubContextMock,
+  createOctokitMock,
+  TEST_PREDICATE,
+  TEST_SUBJECT_WITH_REGISTRY
+} from '../fixtures/mocks'
+
+import type { Attestation } from '@actions/attest'
+import type { Descriptor } from '@sigstore/oci'
+
+// Mock functions
+const mockGetOctokit = jest.fn()
+const mockAttest = jest.fn<() => Promise<Attestation>>()
+const mockCreateStorageRecord = jest.fn<() => Promise<number[]>>()
+const mockGetRegistryCredentials = jest.fn()
+const mockAttachArtifactToImage = jest.fn<() => Promise<Descriptor>>()
+
+// Mutable context for tests
+const mockContext = createGitHubContextMock()
+
+// Mock @actions/github
+jest.unstable_mockModule('@actions/github', () => ({
+  getOctokit: mockGetOctokit,
+  context: mockContext
+}))
+
+// Mock @actions/attest
+jest.unstable_mockModule('@actions/attest', () => ({
+  attest: mockAttest,
+  createStorageRecord: mockCreateStorageRecord
+}))
+
+// Mock @sigstore/oci
+jest.unstable_mockModule('@sigstore/oci', () => ({
+  getRegistryCredentials: mockGetRegistryCredentials,
+  attachArtifactToImage: mockAttachArtifactToImage
+}))
+
+// Dynamic imports after mocking
+const { createAttestation, repoOwnerIsOrg } = await import('../../src/attest')
+
+describe('repoOwnerIsOrg', () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it('should return true when repo owner is an Organization', async () => {
+    mockGetOctokit.mockReturnValue(createOctokitMock('Organization'))
+
+    const result = await repoOwnerIsOrg('test-token')
+
+    expect(result).toBe(true)
+    expect(mockGetOctokit).toHaveBeenCalledWith('test-token')
+  })
+
+  it('should return false when repo owner is a User', async () => {
+    mockGetOctokit.mockReturnValue(createOctokitMock('User'))
+
+    const result = await repoOwnerIsOrg('test-token')
+
+    expect(result).toBe(false)
+  })
+})
+
+describe('createAttestation', () => {
+  const defaultOpts = {
+    sigstoreInstance: 'github' as const,
+    pushToRegistry: false,
+    createStorageRecord: false,
+    githubToken: 'test-token'
+  }
+
+  beforeEach(() => {
+    jest.clearAllMocks()
+
+    mockAttest.mockResolvedValue(createAttestationResult())
+    mockGetRegistryCredentials.mockReturnValue({
+      username: 'test-user',
+      password: 'test-pass'
+    })
+    mockAttachArtifactToImage.mockResolvedValue({
+      digest: 'sha256:attestation-digest',
+      mediaType: 'application/vnd.dev.sigstore.bundle.v0.3+json',
+      size: 1234
+    })
+    mockCreateStorageRecord.mockResolvedValue([12345])
+    mockGetOctokit.mockReturnValue(createOctokitMock('Organization'))
+  })
+
+  describe('basic attestation', () => {
+    it('should call attest with correct parameters', async () => {
+      const subjects = [TEST_SUBJECT_WITH_REGISTRY]
+
+      await createAttestation(subjects, TEST_PREDICATE, defaultOpts)
+
+      expect(mockAttest).toHaveBeenCalledWith({
+        subjects,
+        predicateType: TEST_PREDICATE.type,
+        predicate: TEST_PREDICATE.params,
+        sigstore: 'github',
+        token: 'test-token'
+      })
+    })
+
+    it('should return attestation result', async () => {
+      const subjects = [TEST_SUBJECT_WITH_REGISTRY]
+
+      const result = await createAttestation(
+        subjects,
+        TEST_PREDICATE,
+        defaultOpts
+      )
+
+      expect(result.attestationID).toBe('att-123')
+      expect(result.certificate).toContain('BEGIN CERTIFICATE')
+      expect(result.tlogID).toBe('tlog-123')
+    })
+  })
+
+  describe('registry push', () => {
+    const pushOpts = { ...defaultOpts, pushToRegistry: true }
+
+    it('should push attestation to registry when enabled', async () => {
+      const subjects = [TEST_SUBJECT_WITH_REGISTRY]
+
+      const result = await createAttestation(subjects, TEST_PREDICATE, pushOpts)
+
+      expect(mockGetRegistryCredentials).toHaveBeenCalledWith(subjects[0].name)
+      expect(mockAttachArtifactToImage).toHaveBeenCalled()
+      expect(result.attestationDigest).toBe('sha256:attestation-digest')
+    })
+
+    it('should skip registry push for multiple subjects', async () => {
+      const subjects = [TEST_SUBJECT_WITH_REGISTRY, TEST_SUBJECT_WITH_REGISTRY]
+
+      await createAttestation(subjects, TEST_PREDICATE, pushOpts)
+
+      expect(mockAttachArtifactToImage).not.toHaveBeenCalled()
+    })
+  })
+
+  describe('storage record creation', () => {
+    const storageOpts = {
+      ...defaultOpts,
+      pushToRegistry: true,
+      createStorageRecord: true,
+      subjectVersion: '1.2.3'
+    }
+
+    it('should create storage record when enabled and owner is org', async () => {
+      const subjects = [TEST_SUBJECT_WITH_REGISTRY]
+
+      const result = await createAttestation(
+        subjects,
+        TEST_PREDICATE,
+        storageOpts
+      )
+
+      expect(mockCreateStorageRecord).toHaveBeenCalledWith(
+        expect.objectContaining({ version: '1.2.3' }),
+        expect.anything(),
+        expect.anything()
+      )
+      expect(result.storageRecordIds).toEqual([12345])
+    })
+
+    it('should omit version from storage record when subjectVersion is empty', async () => {
+      const subjects = [TEST_SUBJECT_WITH_REGISTRY]
+      const opts = { ...storageOpts, subjectVersion: '' }
+
+      await createAttestation(subjects, TEST_PREDICATE, opts)
+
+      expect(mockCreateStorageRecord).toHaveBeenCalledWith(
+        expect.objectContaining({ version: undefined }),
+        expect.anything(),
+        expect.anything()
+      )
+    })
+
+    it('should skip storage record when owner is User', async () => {
+      mockGetOctokit.mockReturnValue(createOctokitMock('User'))
+      const subjects = [TEST_SUBJECT_WITH_REGISTRY]
+
+      const result = await createAttestation(
+        subjects,
+        TEST_PREDICATE,
+        storageOpts
+      )
+
+      expect(mockCreateStorageRecord).not.toHaveBeenCalled()
+      expect(result.storageRecordIds).toBeUndefined()
+    })
+
+    it('should skip storage record when createStorageRecord is false', async () => {
+      const subjects = [TEST_SUBJECT_WITH_REGISTRY]
+      const opts = { ...storageOpts, createStorageRecord: false }
+
+      await createAttestation(subjects, TEST_PREDICATE, opts)
+
+      expect(mockCreateStorageRecord).not.toHaveBeenCalled()
+    })
+
+    it('should handle empty storage records gracefully', async () => {
+      mockCreateStorageRecord.mockResolvedValue([])
+      const subjects = [TEST_SUBJECT_WITH_REGISTRY]
+
+      const result = await createAttestation(
+        subjects,
+        TEST_PREDICATE,
+        storageOpts
+      )
+
+      expect(result.storageRecordIds).toEqual([])
+    })
+
+    it('should continue when storage record creation fails', async () => {
+      mockCreateStorageRecord.mockRejectedValue(new Error('Permission denied'))
+      const subjects = [TEST_SUBJECT_WITH_REGISTRY]
+
+      // Should not throw
+      const result = await createAttestation(
+        subjects,
+        TEST_PREDICATE,
+        storageOpts
+      )
+
+      expect(result.attestationID).toBe('att-123')
+      expect(result.storageRecordIds).toBeUndefined()
+    })
+  })
+
+  describe('sigstore instance selection', () => {
+    it('should use public-good sigstore instance when specified', async () => {
+      const subjects = [TEST_SUBJECT_WITH_REGISTRY]
+      const opts = { ...defaultOpts, sigstoreInstance: 'public-good' as const }
+
+      await createAttestation(subjects, TEST_PREDICATE, opts)
+
+      expect(mockAttest).toHaveBeenCalledWith(
+        expect.objectContaining({ sigstore: 'public-good' })
+      )
+    })
+  })
+})

__tests__/integration/main.test.ts

@@ -0,0 +1,455 @@
+import { jest } from '@jest/globals'
+import fs from 'fs/promises'
+import os from 'os'
+import path from 'path'
+import {
+  createAttestationResult,
+  createOctokitMock,
+  TEST_PROVENANCE_PREDICATE
+} from '../fixtures/mocks'
+
+import type { Attestation, Predicate } from '@actions/attest'
+import type { Descriptor } from '@sigstore/oci'
+import type { RunInputs } from '../../src/main'
+
+// Create persistent mock functions
+const infoMock = jest.fn()
+const warningMock = jest.fn()
+const debugMock = jest.fn()
+const startGroupMock = jest.fn()
+const endGroupMock = jest.fn()
+const setOutputMock = jest.fn()
+const setFailedMock = jest.fn()
+
+// Create chainable summary mock
+const summaryMock = {
+  write: jest.fn().mockReturnThis(),
+  addRaw: jest.fn().mockReturnThis(),
+  addHeading: jest.fn().mockReturnThis(),
+  addLink: jest.fn().mockReturnThis(),
+  addTable: jest.fn().mockReturnThis(),
+  addBreak: jest.fn().mockReturnThis(),
+  addSeparator: jest.fn().mockReturnThis(),
+  addQuote: jest.fn().mockReturnThis(),
+  addCodeBlock: jest.fn().mockReturnThis(),
+  addList: jest.fn().mockReturnThis(),
+  addImage: jest.fn().mockReturnThis(),
+  addDetails: jest.fn().mockReturnThis(),
+  addEOL: jest.fn().mockReturnThis(),
+  emptyBuffer: jest.fn().mockReturnThis(),
+  stringify: jest.fn().mockReturnValue(''),
+  isEmptyBuffer: jest.fn().mockReturnValue(true),
+  clear: jest.fn().mockReturnThis()
+}
+
+const mockGetOctokit = jest.fn()
+const mockAttest = jest.fn<() => Promise<Attestation>>()
+const mockBuildSLSAProvenancePredicate = jest.fn<() => Promise<Predicate>>()
+const mockCreateStorageRecord = jest.fn<() => Promise<number[]>>()
+const mockGetRegistryCredentials = jest.fn()
+const mockAttachArtifactToImage = jest.fn<() => Promise<Descriptor>>()
+
+// Mutable context for tests
+const mockContext = {
+  repo: { owner: 'test-owner', repo: 'test-repo' },
+  payload: { repository: { visibility: 'private' } },
+  serverUrl: 'https://github.com'
+}
+
+// Mock @actions/core
+jest.unstable_mockModule('@actions/core', () => ({
+  info: infoMock,
+  warning: warningMock,
+  debug: debugMock,
+  startGroup: startGroupMock,
+  endGroup: endGroupMock,
+  setOutput: setOutputMock,
+  setFailed: setFailedMock,
+  summary: summaryMock
+}))
+
+// Mock @actions/github
+jest.unstable_mockModule('@actions/github', () => ({
+  getOctokit: mockGetOctokit,
+  context: mockContext
+}))
+
+// Mock @actions/attest
+jest.unstable_mockModule('@actions/attest', () => ({
+  attest: mockAttest,
+  buildSLSAProvenancePredicate: mockBuildSLSAProvenancePredicate,
+  createStorageRecord: mockCreateStorageRecord
+}))
+
+// Mock @sigstore/oci
+jest.unstable_mockModule('@sigstore/oci', () => ({
+  getRegistryCredentials: mockGetRegistryCredentials,
+  attachArtifactToImage: mockAttachArtifactToImage
+}))
+
+// Dynamic import after mocking
+const { run } = await import('../../src/main')
+
+const defaultInputs: RunInputs = {
+  predicate: '',
+  predicateType: '',
+  predicatePath: '',
+  sbomPath: '',
+  subjectName: '',
+  subjectDigest: '',
+  subjectPath: '',
+  subjectChecksums: '',
+  pushToRegistry: false,
+  createStorageRecord: false,
+  subjectVersion: '',
+  showSummary: false,
+  githubToken: 'test-token',
+  privateSigning: false
+}
+
+describe('run', () => {
+  let tempDir: string
+  const originalEnv = { ...process.env }
+
+  beforeEach(async () => {
+    jest.clearAllMocks()
+
+    // Reset chainable summary mocks
+    for (const key of Object.keys(summaryMock)) {
+      if (key !== 'stringify' && key !== 'isEmptyBuffer') {
+        ;(
+          summaryMock[key as keyof typeof summaryMock] as jest.Mock
+        ).mockReturnThis()
+      }
+    }
+
+    mockAttest.mockResolvedValue(createAttestationResult())
+    mockBuildSLSAProvenancePredicate.mockResolvedValue(
+      TEST_PROVENANCE_PREDICATE
+    )
+    mockCreateStorageRecord.mockResolvedValue([12345])
+    mockGetOctokit.mockReturnValue(createOctokitMock('Organization'))
+    mockGetRegistryCredentials.mockReturnValue({ username: 'u', password: 'p' })
+    mockAttachArtifactToImage.mockResolvedValue({
+      digest: 'sha256:abc',
+      mediaType: 'application/vnd.dev.sigstore.bundle.v0.3+json',
+      size: 100
+    })
+
+    // Reset context
+    mockContext.repo = { owner: 'test-owner', repo: 'test-repo' }
+    mockContext.payload = { repository: { visibility: 'private' } }
+
+    // Create temp directory
+    tempDir = await fs.mkdtemp(path.join(os.tmpdir(), 'main-test-'))
+
+    // Set required environment
+    process.env.ACTIONS_ID_TOKEN_REQUEST_URL = 'https://token.url'
+    process.env.ACTIONS_ID_TOKEN_REQUEST_TOKEN = 'test-token'
+    process.env.RUNNER_TEMP = tempDir
+  })
+
+  afterEach(async () => {
+    process.env = { ...originalEnv }
+    await fs.rm(tempDir, { recursive: true, force: true })
+  })
+
+  describe('environment validation', () => {
+    it('should fail when ACTIONS_ID_TOKEN_REQUEST_URL is not set', async () => {
+      delete process.env.ACTIONS_ID_TOKEN_REQUEST_URL
+
+      await run({
+        ...defaultInputs,
+        subjectName: 'artifact',
+        subjectDigest:
+          'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32',
+        predicateType: 'https://example.com/predicate',
+        predicate: '{}'
+      })
+
+      expect(setFailedMock).toHaveBeenCalledWith(
+        expect.objectContaining({
+          message: expect.stringContaining('id-token')
+        })
+      )
+    })
+  })
+
+  describe('subject validation', () => {
+    it('should fail when no subject inputs are provided', async () => {
+      await run(defaultInputs)
+
+      expect(setFailedMock).toHaveBeenCalledWith(
+        expect.objectContaining({
+          message: expect.stringContaining('subject-path')
+        })
+      )
+    })
+  })
+
+  describe('attestation type detection', () => {
+    it('should detect provenance attestation when no predicate inputs provided', async () => {
+      await run({
+        ...defaultInputs,
+        subjectName: 'artifact',
+        subjectDigest:
+          'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
+      })
+
+      expect(infoMock).toHaveBeenCalledWith(
+        'Attestation type: Build Provenance'
+      )
+      expect(mockBuildSLSAProvenancePredicate).toHaveBeenCalled()
+    })
+
+    it('should detect custom attestation when predicate inputs provided', async () => {
+      await run({
+        ...defaultInputs,
+        subjectName: 'artifact',
+        subjectDigest:
+          'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32',
+        predicateType: 'https://example.com/predicate',
+        predicate: '{}'
+      })
+
+      expect(infoMock).toHaveBeenCalledWith('Attestation type: Custom')
+      expect(mockBuildSLSAProvenancePredicate).not.toHaveBeenCalled()
+    })
+
+    it('should detect SBOM attestation when sbom-path provided', async () => {
+      const sbomPath = path.join(tempDir, 'sbom.json')
+      await fs.writeFile(
+        sbomPath,
+        JSON.stringify({
+          spdxVersion: 'SPDX-2.3',
+          SPDXID: 'SPDXRef-DOCUMENT',
+          name: 'test'
+        })
+      )
+
+      await run({
+        ...defaultInputs,
+        subjectName: 'artifact',
+        subjectDigest:
+          'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32',
+        sbomPath
+      })
+
+      expect(infoMock).toHaveBeenCalledWith('Attestation type: SBOM')
+    })
+
+    it('should fail when sbom-path is combined with predicate inputs', async () => {
+      await run({
+        ...defaultInputs,
+        subjectName: 'artifact',
+        subjectDigest:
+          'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32',
+        sbomPath: '/path/to/sbom.json',
+        predicateType: 'https://example.com/predicate'
+      })
+
+      expect(setFailedMock).toHaveBeenCalledWith(
+        expect.objectContaining({
+          message: expect.stringContaining(
+            'Cannot specify sbom-path together with'
+          )
+        })
+      )
+    })
+  })
+
+  describe('successful attestation', () => {
+    const validInputs: RunInputs = {
+      ...defaultInputs,
+      subjectName: 'artifact',
+      subjectDigest:
+        'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32',
+      predicateType: 'https://example.com/predicate',
+      predicate: '{}'
+    }
+
+    it('should create attestation successfully', async () => {
+      await run(validInputs)
+
+      expect(setFailedMock).not.toHaveBeenCalled()
+      expect(mockAttest).toHaveBeenCalled()
+    })
+
+    it('should set output for attestation-id', async () => {
+      await run(validInputs)
+
+      expect(setOutputMock).toHaveBeenCalledWith('attestation-id', 'att-123')
+    })
+
+    it('should set output for attestation-url', async () => {
+      await run(validInputs)
+
+      expect(setOutputMock).toHaveBeenCalledWith(
+        'attestation-url',
+        'https://github.com/test-owner/test-repo/attestations/att-123'
+      )
+    })
+
+    it('should set output for bundle-path', async () => {
+      await run(validInputs)
+
+      expect(setOutputMock).toHaveBeenCalledWith(
+        'bundle-path',
+        expect.stringContaining('attestation.json')
+      )
+    })
+
+    it('should write attestation bundle to file', async () => {
+      await run(validInputs)
+
+      const bundlePath = setOutputMock.mock.calls.find(
+        (call: unknown[]) => call[0] === 'bundle-path'
+      )?.[1] as string
+
+      const content = await fs.readFile(bundlePath, 'utf-8')
+      expect(content).toContain('mediaType')
+    })
+  })
+
+  describe('sigstore instance selection', () => {
+    const validInputs: RunInputs = {
+      ...defaultInputs,
+      subjectName: 'artifact',
+      subjectDigest:
+        'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32',
+      predicateType: 'https://example.com/predicate',
+      predicate: '{}'
+    }
+
+    it('should use github sigstore for private repos', async () => {
+      mockContext.payload = { repository: { visibility: 'private' } }
+
+      await run(validInputs)
+
+      expect(mockAttest).toHaveBeenCalledWith(
+        expect.objectContaining({ sigstore: 'github' })
+      )
+    })
+
+    it('should use public-good sigstore for public repos', async () => {
+      mockContext.payload = { repository: { visibility: 'public' } }
+
+      await run(validInputs)
+
+      expect(mockAttest).toHaveBeenCalledWith(
+        expect.objectContaining({ sigstore: 'public-good' })
+      )
+    })
+
+    it('should use github sigstore when privateSigning is true', async () => {
+      mockContext.payload = { repository: { visibility: 'public' } }
+
+      await run({ ...validInputs, privateSigning: true })
+
+      expect(mockAttest).toHaveBeenCalledWith(
+        expect.objectContaining({ sigstore: 'github' })
+      )
+    })
+  })
+
+  describe('multiple subjects', () => {
+    it('should handle multiple subjects from glob pattern', async () => {
+      // Create test files
+      for (let i = 0; i < 3; i++) {
+        await fs.writeFile(path.join(tempDir, `file-${i}.txt`), `content-${i}`)
+      }
+
+      await run({
+        ...defaultInputs,
+        subjectPath: path.join(tempDir, 'file-*.txt'),
+        predicateType: 'https://example.com/predicate',
+        predicate: '{}'
+      })
+
+      expect(setFailedMock).not.toHaveBeenCalled()
+      expect(infoMock).toHaveBeenCalledWith(
+        expect.stringContaining('3 subjects')
+      )
+    })
+
+    it('should fail when subject count exceeds maximum', async () => {
+      // Create too many files
+      for (let i = 0; i < 1025; i++) {
+        await fs.writeFile(path.join(tempDir, `file-${i}.txt`), `content-${i}`)
+      }
+
+      await run({
+        ...defaultInputs,
+        subjectPath: path.join(tempDir, 'file-*.txt'),
+        predicateType: 'https://example.com/predicate',
+        predicate: '{}'
+      })
+
+      expect(setFailedMock).toHaveBeenCalledWith(
+        expect.objectContaining({
+          message: expect.stringContaining('Too many subjects')
+        })
+      )
+    })
+  })
+
+  describe('summary output', () => {
+    const validInputs: RunInputs = {
+      ...defaultInputs,
+      subjectName: 'artifact',
+      subjectDigest:
+        'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32',
+      predicateType: 'https://example.com/predicate',
+      predicate: '{}',
+      showSummary: true
+    }
+
+    it('should write summary when showSummary is true', async () => {
+      await run(validInputs)
+
+      expect(summaryMock.addHeading).toHaveBeenCalled()
+      expect(summaryMock.write).toHaveBeenCalled()
+    })
+
+    it('should not write summary when showSummary is false', async () => {
+      await run({ ...validInputs, showSummary: false })
+
+      expect(summaryMock.write).not.toHaveBeenCalled()
+    })
+  })
+
+  describe('registry push', () => {
+    const registryInputs: RunInputs = {
+      ...defaultInputs,
+      subjectName: 'ghcr.io/test-owner/test-repo',
+      subjectDigest:
+        'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32',
+      predicateType: 'https://example.com/predicate',
+      predicate: '{}',
+      pushToRegistry: true
+    }
+
+    it('should push attestation to registry when enabled', async () => {
+      await run(registryInputs)
+
+      expect(mockAttachArtifactToImage).toHaveBeenCalled()
+    })
+
+    it('should lowercase subject name for registry push', async () => {
+      await run({
+        ...registryInputs,
+        subjectName: 'ghcr.io/TEST-OWNER/Test-Repo'
+      })
+
+      expect(mockAttest).toHaveBeenCalledWith(
+        expect.objectContaining({
+          subjects: [
+            expect.objectContaining({
+              name: 'ghcr.io/test-owner/test-repo'
+            })
+          ]
+        })
+      )
+    })
+  })
+})

__tests__/integration/provenance.test.ts

@@ -0,0 +1,37 @@
+import type { Predicate } from '@actions/attest'
+import { jest } from '@jest/globals'
+import { TEST_PROVENANCE_PREDICATE } from '../fixtures/mocks'
+
+// Mock function
+const mockBuildSLSAProvenancePredicate = jest.fn<() => Promise<Predicate>>()
+
+// Mock @actions/attest
+jest.unstable_mockModule('@actions/attest', () => ({
+  buildSLSAProvenancePredicate: mockBuildSLSAProvenancePredicate
+}))
+
+// Dynamic import after mocking
+const { generateProvenancePredicate } = await import('../../src/provenance')
+
+describe('generateProvenancePredicate', () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+    mockBuildSLSAProvenancePredicate.mockResolvedValue(TEST_PROVENANCE_PREDICATE)
+  })
+
+  it('should delegate to buildSLSAProvenancePredicate', async () => {
+    const result = await generateProvenancePredicate()
+
+    expect(mockBuildSLSAProvenancePredicate).toHaveBeenCalledTimes(1)
+    expect(result).toEqual(TEST_PROVENANCE_PREDICATE)
+  })
+
+  it('should propagate errors from the underlying function', async () => {
+    const error = new Error('Failed to build provenance predicate')
+    mockBuildSLSAProvenancePredicate.mockRejectedValue(error)
+
+    await expect(generateProvenancePredicate()).rejects.toThrow(
+      'Failed to build provenance predicate'
+    )
+  })
+})

__tests__/main.test.ts

@@ -1,425 +0,0 @@
-/**
- * Unit tests for the action's main functionality, src/main.ts
- *
- * These should be run as if the action was called from a workflow.
- * Specifically, the inputs listed in `action.yml` should be set as environment
- * variables following the pattern `INPUT_<INPUT_NAME>`.
- */
-import * as core from '@actions/core'
-import * as github from '@actions/github'
-import { mockFulcio, mockRekor, mockTSA } from '@sigstore/mock'
-import * as oci from '@sigstore/oci'
-import fs from 'fs/promises'
-import nock from 'nock'
-import os from 'os'
-import path from 'path'
-import { MockAgent, setGlobalDispatcher } from 'undici'
-import { SEARCH_PUBLIC_GOOD_URL } from '../src/endpoints'
-import * as main from '../src/main'
-
-// Mock the GitHub Actions core library
-const infoMock = jest.spyOn(core, 'info')
-const startGroupMock = jest.spyOn(core, 'startGroup')
-const setOutputMock = jest.spyOn(core, 'setOutput')
-const setFailedMock = jest.spyOn(core, 'setFailed')
-
-// Ensure that setFailed doesn't set an exit code during tests
-setFailedMock.mockImplementation(() => {})
-
-const summaryWriteMock = jest.spyOn(core.summary, 'write')
-summaryWriteMock.mockImplementation(async () => Promise.resolve(core.summary))
-
-// Mock the action's main function
-const runMock = jest.spyOn(main, 'run')
-
-// MockAgent for mocking @actions/github
-const mockAgent = new MockAgent()
-setGlobalDispatcher(mockAgent)
-
-const defaultInputs: main.RunInputs = {
-  predicate: '',
-  predicateType: '',
-  predicatePath: '',
-  subjectName: '',
-  subjectDigest: '',
-  subjectPath: '',
-  subjectChecksums: '',
-  pushToRegistry: false,
-  showSummary: true,
-  githubToken: '',
-  privateSigning: false
-}
-
-describe('action', () => {
-  // Capture original environment variables and GitHub context so we can restore
-  // them after each test
-  const originalEnv = process.env
-  const originalContext = { ...github.context }
-
-  // Mock OIDC token endpoint
-  const tokenURL = 'https://token.url'
-
-  // Fake an OIDC token
-  const oidcSubject = 'foo@bar.com'
-  const oidcPayload = { sub: oidcSubject, iss: '' }
-  const oidcToken = `.${Buffer.from(JSON.stringify(oidcPayload)).toString(
-    'base64'
-  )}.}`
-
-  const subjectName = 'registry/foo/bar'
-  const subjectDigest =
-    'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
-  const predicate = '{}'
-  const predicateType = 'https://in-toto.io/attestation/release/v0.1'
-
-  const attestationID = '1234567890'
-
-  beforeEach(() => {
-    jest.clearAllMocks()
-
-    nock(tokenURL)
-      .get('/')
-      .query({ audience: 'sigstore' })
-      .reply(200, { value: oidcToken })
-
-    mockAgent
-      .get('https://api.github.com')
-      .intercept({
-        path: /^\/repos\/.*\/.*\/attestations$/,
-        method: 'post'
-      })
-      .reply(201, { id: attestationID })
-
-    process.env = {
-      ...originalEnv,
-      ACTIONS_ID_TOKEN_REQUEST_URL: tokenURL,
-      ACTIONS_ID_TOKEN_REQUEST_TOKEN: 'token',
-      RUNNER_TEMP: process.env.RUNNER_TEMP || '/tmp'
-    }
-  })
-
-  afterEach(() => {
-    // Restore the original environment
-    process.env = originalEnv
-
-    // Restore the original github.context
-    setGHContext(originalContext)
-  })
-
-  describe('when ACTIONS_ID_TOKEN_REQUEST_URL is not set', () => {
-    const inputs: main.RunInputs = {
-      ...defaultInputs,
-      subjectDigest,
-      subjectName,
-      predicateType,
-      predicate,
-      githubToken: 'gh-token'
-    }
-
-    beforeEach(() => {
-      // Nullify the OIDC token URL
-      process.env.ACTIONS_ID_TOKEN_REQUEST_URL = ''
-    })
-
-    it('sets a failed status', async () => {
-      await main.run(inputs)
-
-      expect(runMock).toHaveReturned()
-      expect(setFailedMock).toHaveBeenCalledWith(
-        new Error(
-          'missing "id-token" permission. Please add "permissions: id-token: write" to your workflow.'
-        )
-      )
-    })
-  })
-
-  describe('when no inputs are provided', () => {
-    it('sets a failed status', async () => {
-      await main.run(defaultInputs)
-
-      expect(runMock).toHaveReturned()
-      expect(setFailedMock).toHaveBeenCalledWith(
-        new Error(
-          'One of subject-path, subject-digest, or subject-checksums must be provided'
-        )
-      )
-    })
-  })
-
-  describe('when the repository is private', () => {
-    const inputs: main.RunInputs = {
-      ...defaultInputs,
-      subjectDigest,
-      subjectName,
-      predicateType,
-      predicate,
-      githubToken: 'gh-token'
-    }
-
-    beforeEach(async () => {
-      // Set the GH context with private repository visibility and a repo owner.
-      setGHContext({
-        payload: { repository: { visibility: 'private' } },
-        repo: { owner: 'foo', repo: 'bar' }
-      })
-
-      await mockFulcio({
-        baseURL: 'https://fulcio.githubapp.com',
-        strict: false
-      })
-      await mockTSA({ baseURL: 'https://timestamp.githubapp.com' })
-    })
-
-    it('invokes the action w/o error', async () => {
-      await main.run(inputs)
-
-      expect(runMock).toHaveReturned()
-      expect(setFailedMock).not.toHaveBeenCalledWith()
-      expect(infoMock).toHaveBeenNthCalledWith(
-        1,
-        expect.stringMatching(
-          `Attestation created for ${subjectName}@${subjectDigest}`
-        )
-      )
-      expect(startGroupMock).toHaveBeenNthCalledWith(
-        1,
-        expect.stringMatching('GitHub Sigstore')
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        2,
-        expect.stringMatching('-----BEGIN CERTIFICATE-----')
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        3,
-        expect.stringMatching(/attestation uploaded/i)
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        4,
-        expect.stringMatching(attestationID)
-      )
-      expect(setOutputMock).toHaveBeenNthCalledWith(
-        1,
-        'bundle-path',
-        expect.stringMatching('attestation.json')
-      )
-      expect(setOutputMock).toHaveBeenNthCalledWith(
-        2,
-        'attestation-id',
-        expect.stringMatching(attestationID)
-      )
-      expect(setOutputMock).toHaveBeenNthCalledWith(
-        3,
-        'attestation-url',
-        expect.stringContaining(`foo/bar/attestations/${attestationID}`)
-      )
-      expect(setFailedMock).not.toHaveBeenCalled()
-    })
-  })
-
-  describe('when the repository is public', () => {
-    const getRegCredsSpy = jest.spyOn(oci, 'getRegistryCredentials')
-    const attachArtifactSpy = jest.spyOn(oci, 'attachArtifactToImage')
-
-    const inputs: main.RunInputs = {
-      ...defaultInputs,
-      subjectDigest,
-      subjectName,
-      predicateType,
-      predicate,
-      githubToken: 'gh-token',
-      pushToRegistry: true
-    }
-
-    beforeEach(async () => {
-      // Set the GH context with public repository visibility and a repo owner.
-      setGHContext({
-        payload: { repository: { visibility: 'public' } },
-        repo: { owner: 'foo', repo: 'bar' }
-      })
-
-      await mockFulcio({
-        baseURL: 'https://fulcio.sigstore.dev',
-        strict: false
-      })
-      await mockRekor({ baseURL: 'https://rekor.sigstore.dev' })
-
-      getRegCredsSpy.mockImplementation(() => ({
-        username: 'username',
-        password: 'password'
-      }))
-      attachArtifactSpy.mockImplementation(async () =>
-        Promise.resolve({
-          digest: 'sha256:123456',
-          mediaType: 'application/vnd.cncf.notary.v2',
-          size: 123456
-        })
-      )
-    })
-
-    it('invokes the action w/o error', async () => {
-      await main.run(inputs)
-
-      expect(runMock).toHaveReturned()
-      expect(setFailedMock).not.toHaveBeenCalled()
-      expect(getRegCredsSpy).toHaveBeenCalledWith(subjectName)
-      expect(attachArtifactSpy).toHaveBeenCalled()
-      expect(infoMock).toHaveBeenNthCalledWith(
-        1,
-        expect.stringMatching(
-          `Attestation created for ${subjectName}@${subjectDigest}`
-        )
-      )
-      expect(startGroupMock).toHaveBeenNthCalledWith(
-        1,
-        expect.stringMatching('Public Good Sigstore')
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        2,
-        expect.stringMatching('-----BEGIN CERTIFICATE-----')
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        3,
-        expect.stringMatching(/signature uploaded/i)
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        4,
-        expect.stringMatching(SEARCH_PUBLIC_GOOD_URL)
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        5,
-        expect.stringMatching(/attestation uploaded/i)
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        6,
-        expect.stringMatching(attestationID)
-      )
-      expect(setOutputMock).toHaveBeenNthCalledWith(
-        1,
-        'bundle-path',
-        expect.stringMatching('attestation.json')
-      )
-      expect(setOutputMock).toHaveBeenNthCalledWith(
-        2,
-        'attestation-id',
-        expect.stringMatching(attestationID)
-      )
-      expect(setOutputMock).toHaveBeenNthCalledWith(
-        3,
-        'attestation-url',
-        expect.stringContaining(`foo/bar/attestations/${attestationID}`)
-      )
-      expect(setFailedMock).not.toHaveBeenCalled()
-    })
-  })
-
-  describe('when the subject count is greater than 1', () => {
-    let dir = ''
-    const filename = 'subject'
-
-    beforeEach(async () => {
-      const subjectCount = 5
-      const content = 'file content'
-
-      // Set-up temp directory
-      const tmpDir = await fs.realpath(os.tmpdir())
-      dir = await fs.mkdtemp(tmpDir + path.sep)
-
-      // Add files for glob testing
-      for (let i = 0; i < subjectCount; i++) {
-        await fs.writeFile(path.join(dir, `${filename}-${i}`), content)
-      }
-
-      // Set the GH context with private repository visibility and a repo owner.
-      setGHContext({
-        payload: { repository: { visibility: 'private' } },
-        repo: { owner: 'foo', repo: 'bar' }
-      })
-
-      // Set-up a Fulcio mock for each subject
-      await mockFulcio({
-        baseURL: 'https://fulcio.githubapp.com',
-        strict: false
-      })
-
-      // Set-up a TSA mock for each subject
-      await mockTSA({ baseURL: 'https://timestamp.githubapp.com' })
-    })
-
-    afterEach(async () => {
-      // Clean-up temp directory
-      await fs.rm(dir, { recursive: true })
-    })
-
-    it('invokes the action w/o error', async () => {
-      const inputs: main.RunInputs = {
-        ...defaultInputs,
-        subjectPath: path.join(dir, `${filename}-*`),
-        predicateType,
-        predicate,
-        githubToken: 'gh-token'
-      }
-      await main.run(inputs)
-
-      expect(runMock).toHaveReturned()
-      expect(setFailedMock).not.toHaveBeenCalled()
-      expect(infoMock).toHaveBeenNthCalledWith(
-        1,
-        expect.stringMatching('Attestation created for 5 subjects')
-      )
-    })
-  })
-
-  describe('when the subject count exceeds the max', () => {
-    let dir = ''
-    const filename = 'subject'
-
-    beforeEach(async () => {
-      const subjectCount = 1025
-      const content = 'file content'
-
-      // Set-up temp directory
-      const tmpDir = await fs.realpath(os.tmpdir())
-      dir = await fs.mkdtemp(tmpDir + path.sep)
-
-      // Add files for glob testing
-      for (let i = 0; i < subjectCount; i++) {
-        await fs.writeFile(path.join(dir, `${filename}-${i}`), content)
-      }
-
-      // Set the GH context with private repository visibility and a repo owner.
-      setGHContext({
-        payload: { repository: { visibility: 'private' } },
-        repo: { owner: 'foo', repo: 'bar' }
-      })
-    })
-
-    afterEach(async () => {
-      // Clean-up temp directory
-      await fs.rm(dir, { recursive: true })
-    })
-
-    it('sets a failed status', async () => {
-      const inputs: main.RunInputs = {
-        ...defaultInputs,
-        subjectPath: path.join(dir, `${filename}-*`),
-        predicateType,
-        predicate,
-        githubToken: 'gh-token'
-      }
-      await main.run(inputs)
-
-      expect(runMock).toHaveReturned()
-      expect(setFailedMock).toHaveBeenCalledWith(
-        new Error(
-          'Too many subjects specified. The maximum number of subjects is 1024.'
-        )
-      )
-    })
-  })
-})
-
-// Stubbing the GitHub context is a bit tricky. We need to use
-// `Object.defineProperty` because `github.context` is read-only.
-function setGHContext(context: object): void {
-  Object.defineProperty(github, 'context', { value: context })
-}

__tests__/predicate.test.ts

@@ -1,129 +0,0 @@
-import fs from 'fs/promises'
-import os from 'os'
-import path from 'path'
-import { predicateFromInputs, PredicateInputs } from '../src/predicate'
-
-describe('subjectFromInputs', () => {
-  const blankInputs: PredicateInputs = {
-    predicateType: '',
-    predicate: '',
-    predicatePath: ''
-  }
-
-  describe('when no inputs are provided', () => {
-    it('throws an error', () => {
-      expect(() => predicateFromInputs(blankInputs)).toThrow(/predicate-type/i)
-    })
-  })
-
-  describe('when neither predicate path nor predicate are provided', () => {
-    it('throws an error', () => {
-      const inputs: PredicateInputs = {
-        ...blankInputs,
-        predicateType: 'https://example.com/predicate'
-      }
-
-      expect(() => predicateFromInputs(inputs)).toThrow(
-        /one of predicate-path or predicate must be provided/i
-      )
-    })
-  })
-
-  describe('when both predicate path and predicate are provided', () => {
-    it('throws an error', () => {
-      const inputs: PredicateInputs = {
-        predicateType: 'https://example.com/predicate',
-        predicate: '{}',
-        predicatePath: 'path/to/predicate'
-      }
-
-      expect(() => predicateFromInputs(inputs)).toThrow(
-        /only one of predicate-path or predicate may be provided/i
-      )
-    })
-  })
-
-  describe('when specifying a predicate path', () => {
-    const predicateType = 'https://example.com/predicate'
-    const content = '{}'
-    let predicatePath = ''
-
-    beforeEach(async () => {
-      // Set-up temp directory
-      const tmpDir = await fs.realpath(os.tmpdir())
-      const dir = await fs.mkdtemp(tmpDir + path.sep)
-
-      const filename = 'subject'
-      predicatePath = path.join(dir, filename)
-
-      // Write file to temp directory
-      await fs.writeFile(predicatePath, content)
-    })
-
-    afterEach(async () => {
-      // Clean-up temp directory
-      await fs.rm(path.parse(predicatePath).dir, { recursive: true })
-    })
-
-    it('returns the predicate', () => {
-      const inputs: PredicateInputs = {
-        ...blankInputs,
-        predicateType,
-        predicatePath
-      }
-      expect(predicateFromInputs(inputs)).toEqual({
-        type: predicateType,
-        params: JSON.parse(content)
-      })
-    })
-  })
-
-  describe('when specifying a predicate path that does not exist', () => {
-    const predicateType = 'https://example.com/predicate'
-    const predicatePath = 'foo'
-
-    it('returns the predicate', () => {
-      const inputs: PredicateInputs = {
-        ...blankInputs,
-        predicateType,
-        predicatePath
-      }
-      expect(() => predicateFromInputs(inputs)).toThrow(/file not found/)
-    })
-  })
-
-  describe('when specifying a predicate value', () => {
-    const predicateType = 'https://example.com/predicate'
-    const content = '{}'
-
-    it('returns the predicate', () => {
-      const inputs: PredicateInputs = {
-        ...blankInputs,
-        predicateType,
-        predicate: content
-      }
-
-      expect(predicateFromInputs(inputs)).toEqual({
-        type: predicateType,
-        params: JSON.parse(content)
-      })
-    })
-  })
-
-  describe('when specifying a predicate value exceeding the max size', () => {
-    const predicateType = 'https://example.com/predicate'
-    const content = JSON.stringify({ a: 'a'.repeat(16 * 1024 * 1024) })
-
-    it('throws an error', () => {
-      const inputs: PredicateInputs = {
-        ...blankInputs,
-        predicateType,
-        predicate: content
-      }
-
-      expect(() => predicateFromInputs(inputs)).toThrow(
-        /predicate string exceeds maximum/
-      )
-    })
-  })
-})

__tests__/style.test.ts

@@ -1,15 +0,0 @@
-import { highlight, mute } from '../src/style'
-
-describe('style', () => {
-  describe('highlight', () => {
-    it('adds cyan color to the string', () => {
-      expect(highlight('foo')).toBe('\x1B[36mfoo\x1B[39m')
-    })
-  })
-
-  describe('mute', () => {
-    it('adds gray color to the string', () => {
-      expect(mute('foo')).toBe('\x1B[38;5;244mfoo\x1B[39m')
-    })
-  })
-})

__tests__/subject.test.ts

@@ -1,567 +0,0 @@
-import crypto from 'crypto'
-import fs from 'fs/promises'
-import os from 'os'
-import path from 'path'
-import {
-  formatSubjectDigest,
-  subjectFromInputs,
-  SubjectInputs
-} from '../src/subject'
-
-describe('subjectFromInputs', () => {
-  const blankInputs: SubjectInputs = {
-    subjectPath: '',
-    subjectName: '',
-    subjectDigest: '',
-    subjectChecksums: ''
-  }
-
-  describe('when no inputs are provided', () => {
-    it('throws an error', async () => {
-      await expect(subjectFromInputs(blankInputs)).rejects.toThrow(
-        /one of subject-path, subject-digest, or subject-checksums must be provided/i
-      )
-    })
-  })
-
-  describe('when both subject path and subject digest are provided', () => {
-    it('throws an error', async () => {
-      const inputs: SubjectInputs = {
-        subjectName: 'foo',
-        subjectPath: 'path/to/subject',
-        subjectDigest: 'digest',
-        subjectChecksums: ''
-      }
-
-      await expect(subjectFromInputs(inputs)).rejects.toThrow(
-        /only one of subject-path, subject-digest, or subject-checksums may be provided/i
-      )
-    })
-  })
-
-  describe('when both subject path and subject checksums are provided', () => {
-    it('throws an error', async () => {
-      const inputs: SubjectInputs = {
-        subjectName: '',
-        subjectPath: 'path/to/subject',
-        subjectDigest: '',
-        subjectChecksums: 'path/to/checksums'
-      }
-
-      await expect(subjectFromInputs(inputs)).rejects.toThrow(
-        /only one of subject-path, subject-digest, or subject-checksums may be provided/i
-      )
-    })
-  })
-
-  describe('when both subject digest and subject checksums are provided', () => {
-    it('throws an error', async () => {
-      const inputs: SubjectInputs = {
-        subjectName: 'foo',
-        subjectPath: '',
-        subjectDigest: 'digest',
-        subjectChecksums: 'path/to/checksums'
-      }
-
-      await expect(subjectFromInputs(inputs)).rejects.toThrow(
-        /only one of subject-path, subject-digest, or subject-checksums may be provided/i
-      )
-    })
-  })
-
-  describe('when subject digest is provided but not the name', () => {
-    it('throws an error', async () => {
-      const inputs: SubjectInputs = {
-        ...blankInputs,
-        subjectDigest: 'digest'
-      }
-
-      await expect(subjectFromInputs(inputs)).rejects.toThrow(
-        /subject-name must be provided when using subject-digest/i
-      )
-    })
-  })
-
-  describe('when specifying a subject digest', () => {
-    const name = 'Subject'
-
-    describe('when the digest is malformed', () => {
-      it('throws an error', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectDigest: 'digest',
-          subjectName: name
-        }
-
-        await expect(subjectFromInputs(inputs)).rejects.toThrow(
-          /subject-digest must be in the format "sha256:<hex-digest>"/i
-        )
-      })
-    })
-
-    describe('when the algorithm is not supported', () => {
-      it('throws an error', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectDigest: 'md5:deadbeef',
-          subjectName: name
-        }
-
-        await expect(subjectFromInputs(inputs)).rejects.toThrow(
-          /subject-digest must be in the format "sha256:<hex-digest>"/i
-        )
-      })
-    })
-
-    describe('when the sha256 digest is malformed', () => {
-      it('throws an error', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectDigest: 'sha256:deadbeef',
-          subjectName: name
-        }
-
-        await expect(subjectFromInputs(inputs)).rejects.toThrow(
-          /subject-digest must be in the format "sha256:<hex-digest>"/i
-        )
-      })
-    })
-
-    describe('when the sha256 digest is valid', () => {
-      const alg = 'sha256'
-      const digest =
-        '7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
-
-      it('returns the subject', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectDigest: `${alg}:${digest}`,
-          subjectName: name
-        }
-
-        const subject = await subjectFromInputs(inputs)
-
-        expect(subject).toBeDefined()
-        expect(subject).toHaveLength(1)
-        expect(subject[0].name).toEqual(name)
-        expect(subject[0].digest).toEqual({ [alg]: digest })
-      })
-    })
-
-    describe('when the downcaseName is true', () => {
-      const imageName = 'ghcr.io/FOO/bar'
-      const alg = 'sha256'
-      const digest =
-        '7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
-
-      it('returns the subject (with name downcased)', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectDigest: `${alg}:${digest}`,
-          subjectName: imageName,
-          downcaseName: true
-        }
-
-        const subject = await subjectFromInputs(inputs)
-
-        expect(subject).toBeDefined()
-        expect(subject).toHaveLength(1)
-        expect(subject[0].name).toEqual(imageName.toLowerCase())
-        expect(subject[0].digest).toEqual({ [alg]: digest })
-      })
-    })
-  })
-
-  describe('when specifying a subject path', () => {
-    describe('when the file does NOT exist', () => {
-      it('throws an error', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectPath: '/f/a/k/e'
-        }
-
-        await expect(subjectFromInputs(inputs)).rejects.toThrow(
-          /could not find subject at path/i
-        )
-      })
-    })
-  })
-
-  describe('when the file exists', () => {
-    let dir = ''
-    const filename = 'subject'
-    const content = 'file content'
-
-    const expectedDigest = crypto
-      .createHash('sha256')
-      .update(content)
-      .digest('hex')
-
-    beforeEach(async () => {
-      // Set-up temp directory
-      const tmpDir = await fs.realpath(os.tmpdir())
-      dir = await fs.mkdtemp(tmpDir + path.sep)
-
-      // Write file to temp directory
-      await fs.writeFile(path.join(dir, filename), content)
-
-      // Add files for glob testing
-      for (let i = 0; i < 3; i++) {
-        await fs.writeFile(path.join(dir, `${filename}-${i}`), content)
-        await fs.writeFile(path.join(dir, `other-${i}`), content)
-      }
-    })
-
-    afterEach(async () => {
-      // Clean-up temp directory
-      await fs.rm(dir, { recursive: true })
-    })
-
-    describe('when no name is provided', () => {
-      it('returns the subject', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectPath: path.join(dir, filename)
-        }
-
-        const subject = await subjectFromInputs(inputs)
-
-        expect(subject).toBeDefined()
-        expect(subject).toHaveLength(1)
-        expect(subject[0].name).toEqual(filename)
-        expect(subject[0].digest).toEqual({ sha256: expectedDigest })
-      })
-    })
-
-    describe('when a name is provided', () => {
-      const name = 'mysubject'
-
-      it('returns the subject', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectPath: path.join(dir, filename),
-          subjectName: name
-        }
-
-        const subject = await subjectFromInputs(inputs)
-
-        expect(subject).toBeDefined()
-        expect(subject).toHaveLength(1)
-        expect(subject[0].name).toEqual(name)
-        expect(subject[0].digest).toEqual({ sha256: expectedDigest })
-      })
-    })
-
-    describe('when a file glob is supplied', () => {
-      it('returns the multiple subjects', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectPath: path.join(dir, 'subject-*')
-        }
-
-        const subjects = await subjectFromInputs(inputs)
-
-        expect(subjects).toBeDefined()
-        expect(subjects).toHaveLength(3)
-
-        subjects.forEach((subject, i) => {
-          expect(subject.name).toEqual(`${filename}-${i}`)
-          expect(subject.digest).toEqual({ sha256: expectedDigest })
-        })
-      })
-    })
-
-    describe('when a file glob is supplied which also matches non-files', () => {
-      it('returns the subjects (excluding non-files)', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectPath: `${dir}*`
-        }
-
-        const subjects = await subjectFromInputs(inputs)
-
-        expect(subjects).toBeDefined()
-        expect(subjects).toHaveLength(7)
-      })
-    })
-
-    describe('when a comma-separated list is supplied', () => {
-      it('returns the multiple subjects', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectPath: `${path.join(dir, 'subject-1')},${path.join(dir, 'subject-2')}`
-        }
-
-        const subjects = await subjectFromInputs(inputs)
-
-        expect(subjects).toBeDefined()
-        expect(subjects).toHaveLength(2)
-
-        expect(subjects).toContainEqual({
-          name: 'subject-1',
-          digest: { sha256: expectedDigest }
-        })
-        expect(subjects).toContainEqual({
-          name: 'subject-2',
-          digest: { sha256: expectedDigest }
-        })
-      })
-    })
-
-    describe('when a multi-line list is supplied', () => {
-      it('returns the multiple subjects', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectPath: `${path.join(dir, 'subject-0')}\n${path.join(dir, 'subject-2')}`
-        }
-
-        const subjects = await subjectFromInputs(inputs)
-
-        expect(subjects).toBeDefined()
-        expect(subjects).toHaveLength(2)
-
-        expect(subjects).toContainEqual({
-          name: 'subject-0',
-          digest: { sha256: expectedDigest }
-        })
-        expect(subjects).toContainEqual({
-          name: 'subject-2',
-          digest: { sha256: expectedDigest }
-        })
-      })
-    })
-
-    describe('when an excluding glob is supplied', () => {
-      it('returns the multiple subjects', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectPath: `${path.join(dir, 'subject-*')},!${path.join(dir, 'subject-1')}`
-        }
-
-        const subjects = await subjectFromInputs(inputs)
-
-        expect(subjects).toBeDefined()
-        expect(subjects).toHaveLength(2)
-
-        expect(subjects).toContainEqual({
-          name: 'subject-0',
-          digest: { sha256: expectedDigest }
-        })
-        expect(subjects).toContainEqual({
-          name: 'subject-2',
-          digest: { sha256: expectedDigest }
-        })
-      })
-    })
-
-    describe('when a multi-line glob list is supplied', () => {
-      it('returns the multiple subjects', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectPath: `${path.join(dir, 'subject-*')}\n  ${path.join(dir, 'other-*')} `
-        }
-
-        const subjects = await subjectFromInputs(inputs)
-
-        expect(subjects).toBeDefined()
-        expect(subjects).toHaveLength(6)
-
-        expect(subjects).toContainEqual({
-          name: 'subject-0',
-          digest: { sha256: expectedDigest }
-        })
-        expect(subjects).toContainEqual({
-          name: 'subject-1',
-          digest: { sha256: expectedDigest }
-        })
-        expect(subjects).toContainEqual({
-          name: 'subject-2',
-          digest: { sha256: expectedDigest }
-        })
-
-        expect(subjects).toContainEqual({
-          name: 'other-0',
-          digest: { sha256: expectedDigest }
-        })
-        expect(subjects).toContainEqual({
-          name: 'other-1',
-          digest: { sha256: expectedDigest }
-        })
-        expect(subjects).toContainEqual({
-          name: 'other-2',
-          digest: { sha256: expectedDigest }
-        })
-      })
-    })
-
-    describe('when duplicate subjects are supplied', () => {
-      let otherDir = ''
-
-      // Add duplicate subject in alternate directory
-      beforeEach(async () => {
-        // Set-up temp directory
-        const tmpDir = await fs.realpath(os.tmpdir())
-        otherDir = await fs.mkdtemp(tmpDir + path.sep)
-
-        // Write file to temp directory
-        await fs.writeFile(path.join(otherDir, filename), content)
-      })
-
-      it('returns de-duplicated subjects', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectPath: `${path.join(dir, 'subject')}, ${path.join(otherDir, 'subject')} `
-        }
-        const subjects = await subjectFromInputs(inputs)
-
-        expect(subjects).toBeDefined()
-        expect(subjects).toHaveLength(1)
-      })
-    })
-  })
-
-  describe('when specifying a subject checksums file', () => {
-    const checksums = `
-187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d  demo_0.0.1_linux_amd64
-badline
-5d8b4751ef31f9440d843fcfa4e53ca2e25b1cb1f13fd355fdc7c24b41fe645293291ea9297ba3989078abb77ebbaac66be073618a9e4974dbd0361881d4c718 demo_0.0.1_darwin_arm64`
-
-    let dir = ''
-    const filename = 'checksums'
-
-    beforeEach(async () => {
-      // Set-up temp directory
-      const tmpDir = await fs.realpath(os.tmpdir())
-      dir = await fs.mkdtemp(tmpDir + path.sep)
-
-      // Write file to temp directory
-      await fs.writeFile(path.join(dir, filename), checksums)
-    })
-
-    afterEach(async () => {
-      // Clean-up temp directory
-      await fs.rm(dir, { recursive: true })
-    })
-
-    describe('when the specified path is NOT a file', () => {
-      it('throws an error', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectChecksums: dir
-        }
-        await expect(subjectFromInputs(inputs)).rejects.toThrow(
-          /subject checksums file not found/i
-        )
-      })
-    })
-
-    describe('when the specific path is a file', () => {
-      it('returns the multiple subjects', async () => {
-        const inputs: SubjectInputs = {
-          ...blankInputs,
-          subjectChecksums: path.join(dir, filename)
-        }
-        const subjects = await subjectFromInputs(inputs)
-
-        expect(subjects).toBeDefined()
-        expect(subjects).toHaveLength(2)
-
-        expect(subjects).toContainEqual({
-          name: 'demo_0.0.1_linux_amd64',
-          digest: {
-            sha256:
-              '187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d'
-          }
-        })
-        expect(subjects).toContainEqual({
-          name: 'demo_0.0.1_darwin_arm64',
-          digest: {
-            sha512:
-              '5d8b4751ef31f9440d843fcfa4e53ca2e25b1cb1f13fd355fdc7c24b41fe645293291ea9297ba3989078abb77ebbaac66be073618a9e4974dbd0361881d4c718'
-          }
-        })
-      })
-    })
-  })
-
-  describe('when specifying a subject checksums string', () => {
-    const checksums = `
-f861e68a080799ca83104630b56abb90d8dbcc5f8b5a8639cb691e269838f29e  demo_0.0.1_linux_386
-187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d *demo_0.0.1_linux_amd64
-9ecbf449e286a8a8748c161c52aa28b6b2fc64ab86f94161c5d1b3abc18156c5 demo_0.0.1_linux_arm64`
-
-    it('returns the multiple subjects', async () => {
-      const inputs: SubjectInputs = {
-        ...blankInputs,
-        subjectChecksums: checksums
-      }
-      const subjects = await subjectFromInputs(inputs)
-
-      expect(subjects).toBeDefined()
-      expect(subjects).toHaveLength(3)
-
-      expect(subjects).toContainEqual({
-        name: 'demo_0.0.1_linux_386',
-        digest: {
-          sha256:
-            'f861e68a080799ca83104630b56abb90d8dbcc5f8b5a8639cb691e269838f29e'
-        }
-      })
-      expect(subjects).toContainEqual({
-        name: 'demo_0.0.1_linux_amd64',
-        digest: {
-          sha256:
-            '187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d'
-        }
-      })
-      expect(subjects).toContainEqual({
-        name: 'demo_0.0.1_linux_arm64',
-        digest: {
-          sha256:
-            '9ecbf449e286a8a8748c161c52aa28b6b2fc64ab86f94161c5d1b3abc18156c5'
-        }
-      })
-    })
-  })
-
-  describe('when specifying a subject checksums string with an unrecognized digest', () => {
-    const checksums = `f861e  demo_0.0.1_linux_386`
-
-    it('throws an error', async () => {
-      const inputs: SubjectInputs = {
-        ...blankInputs,
-        subjectChecksums: checksums
-      }
-
-      await expect(subjectFromInputs(inputs)).rejects.toThrow(
-        /unknown digest algorithm/i
-      )
-    })
-  })
-
-  describe('when specifying a subject checksums string with an invalid digest', () => {
-    const checksums =
-      '!!!!e68a080799ca83104630b56abb90d8dbcc5f8b5a8639cb691e269838f29e  demo_0.0.1_linux_386'
-
-    it('throws an error', async () => {
-      const inputs: SubjectInputs = {
-        ...blankInputs,
-        subjectChecksums: checksums
-      }
-
-      await expect(subjectFromInputs(inputs)).rejects.toThrow(/invalid digest/i)
-    })
-  })
-})
-
-describe('subjectDigest', () => {
-  it('returns the digest', () => {
-    const subject = {
-      name: 'foo',
-      digest: { sha1: 'deadbeef' }
-    }
-
-    const digest = formatSubjectDigest(subject)
-    expect(digest).toEqual('sha1:deadbeef')
-  })
-})

__tests__/unit/detect.test.ts

@@ -0,0 +1,168 @@
+import {
+  detectAttestationType,
+  validateAttestationInputs,
+  DetectionInputs
+} from '../../src/detect'
+
+describe('detectAttestationType', () => {
+  const blankInputs: DetectionInputs = {
+    sbomPath: '',
+    predicateType: '',
+    predicate: '',
+    predicatePath: ''
+  }
+
+  it('should return provenance when no inputs are provided', () => {
+    expect(detectAttestationType(blankInputs)).toBe('provenance')
+  })
+
+  describe('SBOM detection', () => {
+    it('should return sbom when sbom-path is provided', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        sbomPath: '/path/to/sbom.json'
+      }
+      expect(detectAttestationType(inputs)).toBe('sbom')
+    })
+
+    it('should prioritize sbom over custom predicate inputs', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        sbomPath: '/path/to/sbom.json',
+        predicateType: 'https://example.com/predicate'
+      }
+      expect(detectAttestationType(inputs)).toBe('sbom')
+    })
+  })
+
+  describe('custom detection', () => {
+    it('should return custom when predicate-type is provided', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate'
+      }
+      expect(detectAttestationType(inputs)).toBe('custom')
+    })
+
+    it('should return custom when predicate is provided', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicate: '{}'
+      }
+      expect(detectAttestationType(inputs)).toBe('custom')
+    })
+
+    it('should return custom when predicate-path is provided', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicatePath: '/path/to/predicate.json'
+      }
+      expect(detectAttestationType(inputs)).toBe('custom')
+    })
+
+    it('should return custom when predicate-type and predicate are both provided', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate',
+        predicate: '{}'
+      }
+      expect(detectAttestationType(inputs)).toBe('custom')
+    })
+  })
+})
+
+describe('validateAttestationInputs', () => {
+  const blankInputs: DetectionInputs = {
+    sbomPath: '',
+    predicateType: '',
+    predicate: '',
+    predicatePath: ''
+  }
+
+  it('should not throw when no inputs are provided', () => {
+    expect(() => validateAttestationInputs(blankInputs)).not.toThrow()
+  })
+
+  it('should not throw when sbom-path is provided alone', () => {
+    const inputs: DetectionInputs = {
+      ...blankInputs,
+      sbomPath: '/path/to/sbom.json'
+    }
+    expect(() => validateAttestationInputs(inputs)).not.toThrow()
+  })
+
+  describe('sbom-path conflicts', () => {
+    it('should throw when sbom-path is combined with predicate-type', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        sbomPath: '/path/to/sbom.json',
+        predicateType: 'https://example.com/predicate'
+      }
+      expect(() => validateAttestationInputs(inputs)).toThrow(
+        /Cannot specify sbom-path together with/
+      )
+    })
+
+    it('should throw when sbom-path is combined with predicate', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        sbomPath: '/path/to/sbom.json',
+        predicate: '{}'
+      }
+      expect(() => validateAttestationInputs(inputs)).toThrow(
+        /Cannot specify sbom-path together with/
+      )
+    })
+
+    it('should throw when sbom-path is combined with predicate-path', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        sbomPath: '/path/to/sbom.json',
+        predicatePath: '/path/to/predicate.json'
+      }
+      expect(() => validateAttestationInputs(inputs)).toThrow(
+        /Cannot specify sbom-path together with/
+      )
+    })
+  })
+
+  describe('predicate-type requirements', () => {
+    it('should throw when predicate is provided without predicate-type', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicate: '{}'
+      }
+      expect(() => validateAttestationInputs(inputs)).toThrow(
+        /predicate-type is required/
+      )
+    })
+
+    it('should throw when predicate-path is provided without predicate-type', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicatePath: '/path/to/predicate.json'
+      }
+      expect(() => validateAttestationInputs(inputs)).toThrow(
+        /predicate-type is required/
+      )
+    })
+
+    it('should not throw when predicate-type and predicate are provided', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate',
+        predicate: '{}'
+      }
+      expect(() => validateAttestationInputs(inputs)).not.toThrow()
+    })
+
+    it('should not throw when predicate-type and predicate-path are provided', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate',
+        predicatePath: '/path/to/predicate.json'
+      }
+      expect(() => validateAttestationInputs(inputs)).not.toThrow()
+    })
+  })
+})

__tests__/unit/predicate.test.ts

@@ -0,0 +1,142 @@
+import fs from 'fs/promises'
+import os from 'os'
+import path from 'path'
+import { predicateFromInputs, PredicateInputs } from '../../src/predicate'
+
+describe('predicateFromInputs', () => {
+  const blankInputs: PredicateInputs = {
+    predicateType: '',
+    predicate: '',
+    predicatePath: ''
+  }
+
+  let tempDir: string
+
+  beforeEach(async () => {
+    tempDir = await fs.mkdtemp(path.join(os.tmpdir(), 'predicate-test-'))
+  })
+
+  afterEach(async () => {
+    await fs.rm(tempDir, { recursive: true, force: true })
+  })
+
+  describe('input validation', () => {
+    it('should throw when predicate-type is not provided', async () => {
+      await expect(predicateFromInputs(blankInputs)).rejects.toThrow(
+        /predicate-type must be provided/
+      )
+    })
+
+    it('should throw when neither predicate nor predicate-path is provided', async () => {
+      const inputs: PredicateInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate'
+      }
+      await expect(predicateFromInputs(inputs)).rejects.toThrow(
+        /one of predicate-path or predicate must be provided/i
+      )
+    })
+
+    it('should throw when both predicate and predicate-path are provided', async () => {
+      const inputs: PredicateInputs = {
+        predicateType: 'https://example.com/predicate',
+        predicate: '{}',
+        predicatePath: '/path/to/predicate.json'
+      }
+      await expect(predicateFromInputs(inputs)).rejects.toThrow(
+        /only one of predicate-path or predicate may be provided/i
+      )
+    })
+  })
+
+  describe('with predicate string', () => {
+    it('should parse and return the predicate', async () => {
+      const predicateType = 'https://example.com/predicate'
+      const predicateContent = { foo: 'bar', nested: { value: 123 } }
+
+      const inputs: PredicateInputs = {
+        ...blankInputs,
+        predicateType,
+        predicate: JSON.stringify(predicateContent)
+      }
+
+      const result = await predicateFromInputs(inputs)
+
+      expect(result).toEqual({
+        type: predicateType,
+        params: predicateContent
+      })
+    })
+
+    it('should throw when predicate string exceeds max size', async () => {
+      const predicateType = 'https://example.com/predicate'
+      const largeContent = JSON.stringify({ data: 'x'.repeat(16 * 1024 * 1024) })
+
+      const inputs: PredicateInputs = {
+        ...blankInputs,
+        predicateType,
+        predicate: largeContent
+      }
+
+      await expect(predicateFromInputs(inputs)).rejects.toThrow(
+        /predicate string exceeds maximum/
+      )
+    })
+
+    it('should throw when predicate is invalid JSON', async () => {
+      const inputs: PredicateInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate',
+        predicate: 'not valid json'
+      }
+
+      await expect(predicateFromInputs(inputs)).rejects.toThrow(/JSON/)
+    })
+  })
+
+  describe('with predicate path', () => {
+    it('should read and parse predicate from file', async () => {
+      const predicateType = 'https://example.com/predicate'
+      const predicateContent = { buildType: 'test', metadata: { version: '1.0' } }
+      const filePath = path.join(tempDir, 'predicate.json')
+
+      await fs.writeFile(filePath, JSON.stringify(predicateContent))
+
+      const inputs: PredicateInputs = {
+        ...blankInputs,
+        predicateType,
+        predicatePath: filePath
+      }
+
+      const result = await predicateFromInputs(inputs)
+
+      expect(result).toEqual({
+        type: predicateType,
+        params: predicateContent
+      })
+    })
+
+    it('should throw when predicate file does not exist', async () => {
+      const inputs: PredicateInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate',
+        predicatePath: '/nonexistent/file.json'
+      }
+
+      await expect(predicateFromInputs(inputs)).rejects.toThrow(/file not found/)
+    })
+
+    it('should throw when predicate file contains invalid JSON', async () => {
+      const filePath = path.join(tempDir, 'invalid.json')
+      await fs.writeFile(filePath, 'not valid json')
+
+      const inputs: PredicateInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate',
+        predicatePath: filePath
+      }
+
+      await expect(predicateFromInputs(inputs)).rejects.toThrow(/JSON/)
+    })
+  })
+})

__tests__/unit/sbom.test.ts

@@ -0,0 +1,181 @@
+import { jest } from '@jest/globals'
+import fs from 'fs/promises'
+import os from 'os'
+import path from 'path'
+import { parseSBOMFromPath, generateSBOMPredicate, SBOM } from '../../src/sbom'
+
+describe('parseSBOMFromPath', () => {
+  let tempDir: string
+
+  beforeEach(async () => {
+    tempDir = await fs.mkdtemp(path.join(os.tmpdir(), 'sbom-test-'))
+  })
+
+  afterEach(async () => {
+    await fs.rm(tempDir, { recursive: true, force: true })
+  })
+
+  describe('file handling', () => {
+    it('should throw when file does not exist', async () => {
+      await expect(parseSBOMFromPath('/nonexistent/file.json')).rejects.toThrow(
+        /SBOM file not found/
+      )
+    })
+
+    it('should rethrow non-ENOENT errors', async () => {
+      const statSpy = jest.spyOn(fs, 'stat').mockRejectedValueOnce(
+        Object.assign(new Error('Permission denied'), { code: 'EACCES' })
+      )
+
+      await expect(parseSBOMFromPath('/some/file.json')).rejects.toThrow(
+        /Permission denied/
+      )
+
+      statSpy.mockRestore()
+    })
+
+    it('should throw when file contains invalid JSON', async () => {
+      const filePath = path.join(tempDir, 'invalid.json')
+      await fs.writeFile(filePath, 'not valid json')
+
+      await expect(parseSBOMFromPath(filePath)).rejects.toThrow(/JSON/)
+    })
+
+    it('should throw when file exceeds maximum size', async () => {
+      const filePath = path.join(tempDir, 'large.json')
+      const largeContent = 'x'.repeat(17 * 1024 * 1024)
+      await fs.writeFile(filePath, largeContent)
+
+      await expect(parseSBOMFromPath(filePath)).rejects.toThrow(
+        /SBOM file exceeds maximum allowed size/
+      )
+    })
+  })
+
+  describe('SPDX format', () => {
+    const spdxSBOM = {
+      spdxVersion: 'SPDX-2.3',
+      SPDXID: 'SPDXRef-DOCUMENT',
+      name: 'test-package',
+      packages: []
+    }
+
+    it('should parse valid SPDX SBOM', async () => {
+      const filePath = path.join(tempDir, 'sbom.spdx.json')
+      await fs.writeFile(filePath, JSON.stringify(spdxSBOM))
+
+      const result = await parseSBOMFromPath(filePath)
+
+      expect(result.type).toBe('spdx')
+      expect(result.object).toEqual(spdxSBOM)
+    })
+  })
+
+  describe('CycloneDX format', () => {
+    const cyclonedxSBOM = {
+      bomFormat: 'CycloneDX',
+      specVersion: '1.4',
+      serialNumber: 'urn:uuid:12345',
+      components: []
+    }
+
+    it('should parse valid CycloneDX SBOM', async () => {
+      const filePath = path.join(tempDir, 'sbom.cdx.json')
+      await fs.writeFile(filePath, JSON.stringify(cyclonedxSBOM))
+
+      const result = await parseSBOMFromPath(filePath)
+
+      expect(result.type).toBe('cyclonedx')
+      expect(result.object).toEqual(cyclonedxSBOM)
+    })
+  })
+
+  describe('unsupported formats', () => {
+    it('should throw for unrecognized SBOM format', async () => {
+      const filePath = path.join(tempDir, 'invalid-sbom.json')
+      await fs.writeFile(filePath, JSON.stringify({ random: 'data' }))
+
+      await expect(parseSBOMFromPath(filePath)).rejects.toThrow(
+        /Unsupported SBOM format/
+      )
+    })
+
+    it('should throw for SPDX missing SPDXID', async () => {
+      const filePath = path.join(tempDir, 'partial-spdx.json')
+      await fs.writeFile(filePath, JSON.stringify({ spdxVersion: 'SPDX-2.3' }))
+
+      await expect(parseSBOMFromPath(filePath)).rejects.toThrow(
+        /Unsupported SBOM format/
+      )
+    })
+
+    it('should throw for CycloneDX missing required fields', async () => {
+      const filePath = path.join(tempDir, 'partial-cdx.json')
+      await fs.writeFile(filePath, JSON.stringify({ bomFormat: 'CycloneDX' }))
+
+      await expect(parseSBOMFromPath(filePath)).rejects.toThrow(
+        /Unsupported SBOM format/
+      )
+    })
+  })
+})
+
+describe('generateSBOMPredicate', () => {
+  describe('SPDX predicates', () => {
+    it('should generate predicate with correct SPDX type URL', () => {
+      const sbom: SBOM = {
+        type: 'spdx',
+        object: {
+          spdxVersion: 'SPDX-2.3',
+          SPDXID: 'SPDXRef-DOCUMENT',
+          name: 'test-package'
+        }
+      }
+
+      const predicate = generateSBOMPredicate(sbom)
+
+      expect(predicate.type).toBe('https://spdx.dev/Document/v2.3')
+      expect(predicate.params).toEqual(sbom.object)
+    })
+
+    it('should throw when spdxVersion is missing', () => {
+      const sbom: SBOM = {
+        type: 'spdx',
+        object: { SPDXID: 'SPDXRef-DOCUMENT' }
+      }
+
+      expect(() => generateSBOMPredicate(sbom)).toThrow(
+        /Cannot find spdxVersion/
+      )
+    })
+  })
+
+  describe('CycloneDX predicates', () => {
+    it('should generate predicate with correct CycloneDX type URL', () => {
+      const sbom: SBOM = {
+        type: 'cyclonedx',
+        object: {
+          bomFormat: 'CycloneDX',
+          specVersion: '1.4',
+          serialNumber: 'urn:uuid:12345'
+        }
+      }
+
+      const predicate = generateSBOMPredicate(sbom)
+
+      expect(predicate.type).toBe('https://cyclonedx.org/bom')
+      expect(predicate.params).toEqual(sbom.object)
+    })
+  })
+
+  describe('unsupported types', () => {
+    it('should throw for unsupported SBOM type', () => {
+      const sbom = {
+        type: 'unknown' as SBOM['type'],
+        object: { foo: 'bar' }
+      }
+
+      expect(() => generateSBOMPredicate(sbom)).toThrow(/Unsupported SBOM format/)
+    })
+  })
+})

__tests__/unit/style.test.ts

@@ -0,0 +1,27 @@
+import { highlight, mute } from '../../src/style'
+
+describe('style', () => {
+  describe('highlight', () => {
+    it('should wrap text with cyan ANSI color codes', () => {
+      const result = highlight('test message')
+      expect(result).toBe('\x1B[36mtest message\x1B[39m')
+    })
+
+    it('should handle empty strings', () => {
+      const result = highlight('')
+      expect(result).toBe('\x1B[36m\x1B[39m')
+    })
+  })
+
+  describe('mute', () => {
+    it('should wrap text with gray ANSI color codes', () => {
+      const result = mute('test message')
+      expect(result).toBe('\x1B[38;5;244mtest message\x1B[39m')
+    })
+
+    it('should handle empty strings', () => {
+      const result = mute('')
+      expect(result).toBe('\x1B[38;5;244m\x1B[39m')
+    })
+  })
+})

__tests__/unit/subject.test.ts

@@ -0,0 +1,462 @@
+import crypto from 'crypto'
+import fs from 'fs/promises'
+import os from 'os'
+import path from 'path'
+import {
+  subjectFromInputs,
+  formatSubjectDigest,
+  SubjectInputs
+} from '../../src/subject'
+
+describe('subjectFromInputs', () => {
+  const blankInputs: SubjectInputs = {
+    subjectPath: '',
+    subjectName: '',
+    subjectDigest: '',
+    subjectChecksums: ''
+  }
+
+  let tempDir: string
+
+  beforeEach(async () => {
+    tempDir = await fs.mkdtemp(path.join(os.tmpdir(), 'subject-test-'))
+  })
+
+  afterEach(async () => {
+    await fs.rm(tempDir, { recursive: true, force: true })
+  })
+
+  describe('input validation', () => {
+    it('should throw when no inputs are provided', async () => {
+      await expect(subjectFromInputs(blankInputs)).rejects.toThrow(
+        /one of subject-path, subject-digest, or subject-checksums must be provided/i
+      )
+    })
+
+    it('should throw when multiple subject inputs are provided', async () => {
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectPath: '/some/path',
+        subjectDigest: 'sha256:abc123'
+      }
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(
+        /only one of subject-path, subject-digest, or subject-checksums may be provided/i
+      )
+    })
+
+    it('should throw when subject-digest is provided without subject-name', async () => {
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectDigest: 'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
+      }
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(
+        /subject-name must be provided when using subject-digest/i
+      )
+    })
+  })
+
+  describe('with subject-digest', () => {
+    const validDigest = 'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
+
+    it('should return subject with provided name and digest', async () => {
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectName: 'my-artifact',
+        subjectDigest: validDigest
+      }
+
+      const subjects = await subjectFromInputs(inputs)
+
+      expect(subjects).toHaveLength(1)
+      expect(subjects[0].name).toBe('my-artifact')
+      expect(subjects[0].digest).toEqual({
+        sha256: '7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
+      })
+    })
+
+    it('should lowercase name when downcaseName is true', async () => {
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectName: 'ghcr.io/FOO/Bar',
+        subjectDigest: validDigest,
+        downcaseName: true
+      }
+
+      const subjects = await subjectFromInputs(inputs)
+
+      expect(subjects[0].name).toBe('ghcr.io/foo/bar')
+    })
+
+    it('should throw for malformed digest format', async () => {
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectName: 'artifact',
+        subjectDigest: 'invalid-digest'
+      }
+
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(
+        /subject-digest must be in the format/
+      )
+    })
+
+    it('should throw for unsupported hash algorithm', async () => {
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectName: 'artifact',
+        subjectDigest: 'md5:d41d8cd98f00b204e9800998ecf8427e'
+      }
+
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(
+        /subject-digest must be in the format/
+      )
+    })
+
+    it('should throw for incorrect sha256 digest length', async () => {
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectName: 'artifact',
+        subjectDigest: 'sha256:deadbeef'
+      }
+
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(
+        /subject-digest must be in the format/
+      )
+    })
+  })
+
+  describe('with subject-path', () => {
+    const fileContent = 'test file content'
+    const expectedDigest = crypto.createHash('sha256').update(fileContent).digest('hex')
+
+    it('should calculate digest from file', async () => {
+      const filePath = path.join(tempDir, 'artifact.bin')
+      await fs.writeFile(filePath, fileContent)
+
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectPath: filePath
+      }
+
+      const subjects = await subjectFromInputs(inputs)
+
+      expect(subjects).toHaveLength(1)
+      expect(subjects[0].name).toBe('artifact.bin')
+      expect(subjects[0].digest).toEqual({ sha256: expectedDigest })
+    })
+
+    it('should use provided name instead of filename', async () => {
+      const filePath = path.join(tempDir, 'artifact.bin')
+      await fs.writeFile(filePath, fileContent)
+
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectPath: filePath,
+        subjectName: 'custom-name'
+      }
+
+      const subjects = await subjectFromInputs(inputs)
+
+      expect(subjects[0].name).toBe('custom-name')
+    })
+
+    it('should throw when file does not exist', async () => {
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectPath: '/nonexistent/file'
+      }
+
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(
+        /could not find subject at path/i
+      )
+    })
+
+    describe('glob patterns', () => {
+      beforeEach(async () => {
+        for (let i = 0; i < 3; i++) {
+          await fs.writeFile(path.join(tempDir, `file-${i}.txt`), fileContent)
+        }
+      })
+
+      it('should expand glob pattern to multiple subjects', async () => {
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: path.join(tempDir, 'file-*.txt')
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toHaveLength(3)
+        expect(subjects.map(s => s.name).sort()).toEqual([
+          'file-0.txt',
+          'file-1.txt',
+          'file-2.txt'
+        ])
+      })
+
+      it('should handle comma-separated paths', async () => {
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: `${path.join(tempDir, 'file-0.txt')},${path.join(tempDir, 'file-1.txt')}`
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toHaveLength(2)
+      })
+
+      it('should handle newline-separated paths', async () => {
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: `${path.join(tempDir, 'file-0.txt')}\n${path.join(tempDir, 'file-2.txt')}`
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toHaveLength(2)
+      })
+
+      it('should support exclusion patterns', async () => {
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: `${path.join(tempDir, 'file-*.txt')},!${path.join(tempDir, 'file-1.txt')}`
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toHaveLength(2)
+        expect(subjects.map(s => s.name)).not.toContain('file-1.txt')
+      })
+
+      it('should deduplicate subjects with same name and digest', async () => {
+        // Create another directory with same file
+        const otherDir = await fs.mkdtemp(path.join(os.tmpdir(), 'subject-dup-'))
+        await fs.writeFile(path.join(otherDir, 'file-0.txt'), fileContent)
+
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: `${path.join(tempDir, 'file-0.txt')},${path.join(otherDir, 'file-0.txt')}`
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toHaveLength(1)
+
+        await fs.rm(otherDir, { recursive: true, force: true })
+      })
+    })
+
+    it('should exclude directories from glob results', async () => {
+      await fs.mkdir(path.join(tempDir, 'subdir'))
+      await fs.writeFile(path.join(tempDir, 'file.txt'), fileContent)
+
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectPath: path.join(tempDir, '*')
+      }
+
+      const subjects = await subjectFromInputs(inputs)
+
+      expect(subjects).toHaveLength(1)
+      expect(subjects[0].name).toBe('file.txt')
+    })
+
+    it('should throw when too many subjects are specified', async () => {
+      // Create 1025 files (exceeds MAX_SUBJECT_COUNT of 1024)
+      for (let i = 0; i < 1025; i++) {
+        await fs.writeFile(path.join(tempDir, `file-${i}.txt`), `content-${i}`)
+      }
+
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectPath: path.join(tempDir, 'file-*.txt')
+      }
+
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(/too many subjects/i)
+    })
+  })
+
+  describe('with subject-checksums', () => {
+    describe('from string', () => {
+      it('should parse sha256 checksums', async () => {
+        const checksums = `187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d  artifact-linux
+9ecbf449e286a8a8748c161c52aa28b6b2fc64ab86f94161c5d1b3abc18156c5  artifact-darwin`
+
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: checksums
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toHaveLength(2)
+        expect(subjects).toContainEqual({
+          name: 'artifact-linux',
+          digest: { sha256: '187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d' }
+        })
+        expect(subjects).toContainEqual({
+          name: 'artifact-darwin',
+          digest: { sha256: '9ecbf449e286a8a8748c161c52aa28b6b2fc64ab86f94161c5d1b3abc18156c5' }
+        })
+      })
+
+      it('should parse sha512 checksums', async () => {
+        const sha512 = '5d8b4751ef31f9440d843fcfa4e53ca2e25b1cb1f13fd355fdc7c24b41fe645293291ea9297ba3989078abb77ebbaac66be073618a9e4974dbd0361881d4c718'
+        const checksums = `${sha512}  artifact-amd64`
+
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: checksums
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toHaveLength(1)
+        expect(subjects[0].digest).toEqual({ sha512 })
+      })
+
+      it('should handle binary mode flag (*)', async () => {
+        const checksums = `187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d *artifact.bin`
+
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: checksums
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects[0].name).toBe('artifact.bin')
+      })
+
+      it('should handle text mode flag (space)', async () => {
+        const checksums = `187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d  artifact.txt`
+
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: checksums
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects[0].name).toBe('artifact.txt')
+      })
+
+      it('should handle checksums without mode flag', async () => {
+        // Single space between digest and name (no flag character)
+        const checksums = `187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d artifact-no-flag`
+
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: checksums
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects[0].name).toBe('artifact-no-flag')
+      })
+
+      it('should skip malformed lines', async () => {
+        const checksums = `187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d  valid-artifact
+badline
+9ecbf449e286a8a8748c161c52aa28b6b2fc64ab86f94161c5d1b3abc18156c5  another-artifact`
+
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: checksums
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toHaveLength(2)
+      })
+
+      it('should deduplicate identical entries', async () => {
+        const checksums = `187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d  artifact
+187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d  artifact`
+
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: checksums
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toHaveLength(1)
+      })
+
+      it('should throw for invalid digest characters', async () => {
+        const checksums = `!!!!e68a080799ca83104630b56abb90d8dbcc5f8b5a8639cb691e269838f29e  artifact`
+
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: checksums
+        }
+
+        await expect(subjectFromInputs(inputs)).rejects.toThrow(/invalid digest/i)
+      })
+
+      it('should throw for unknown digest algorithm', async () => {
+        const checksums = `f861e  artifact`
+
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: checksums
+        }
+
+        await expect(subjectFromInputs(inputs)).rejects.toThrow(/unknown digest algorithm/i)
+      })
+    })
+
+    describe('from file', () => {
+      it('should read checksums from file', async () => {
+        const checksumFile = path.join(tempDir, 'SHA256SUMS')
+        const checksums = `187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d  artifact-linux
+9ecbf449e286a8a8748c161c52aa28b6b2fc64ab86f94161c5d1b3abc18156c5  artifact-darwin`
+
+        await fs.writeFile(checksumFile, checksums)
+
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: checksumFile
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toHaveLength(2)
+      })
+
+      it('should throw when checksums path is a directory', async () => {
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: tempDir
+        }
+
+        await expect(subjectFromInputs(inputs)).rejects.toThrow(
+          /subject checksums file not found/i
+        )
+      })
+    })
+  })
+})
+
+describe('formatSubjectDigest', () => {
+  it('should format digest as algorithm:hash', () => {
+    const subject = {
+      name: 'artifact',
+      digest: { sha256: 'abc123def456' }
+    }
+
+    expect(formatSubjectDigest(subject)).toBe('sha256:abc123def456')
+  })
+
+  it('should use first algorithm alphabetically when multiple exist', () => {
+    const subject = {
+      name: 'artifact',
+      digest: {
+        sha512: 'longer-hash',
+        sha256: 'shorter-hash'
+      }
+    }
+
+    expect(formatSubjectDigest(subject)).toBe('sha256:shorter-hash')
+  })
+})

action.yml

@@ -30,21 +30,34 @@ inputs:
       attestation. Must specify exactly one of "subject-path", "subject-digest",
       or "subject-checksums".
     required: false
+  subject-version:
+    description: >
+      Version of the subject for the attestation. Only used when
+      "push-to-registry" and "create-storage-record" are both set to true.
+    required: false
+  sbom-path:
+    description: >
+      Path to the JSON-formatted SBOM file (SPDX or CycloneDX) to attest.
+      File size cannot exceed 16MB. When provided, creates an SBOM attestation.
+      Cannot be used together with "predicate-type", "predicate", or
+      "predicate-path".
+    required: false
   predicate-type:
     description: >
-      URI identifying the type of the predicate.
+      URI identifying the type of the predicate. Required when using "predicate"
-    required: true
+      or "predicate-path" for custom attestations.
+    required: false
   predicate:
     description: >
       String containing the value for the attestation predicate. String length
       cannot exceed 16MB. Must supply exactly one of "predicate-path" or
-      "predicate".
+      "predicate" when creating custom attestations.
     required: false
   predicate-path:
     description: >
       Path to the file which contains the content for the attestation predicate.
       File size cannot exceed 16MB. Must supply exactly one of "predicate-path"
-      or "predicate".
+      or "predicate" when creating custom attestations.
     required: false
   push-to-registry:
     description: >
@@ -53,6 +66,12 @@ inputs:
       the "subject-digest" parameter be specified. Defaults to false.
     default: false
     required: false
+  create-storage-record:
+    description: >
+      Whether to create a storage record for the artifact.
+      Requires that push-to-registry is set to true. Defaults to true.
+    default: true
+    required: false
   show-summary:
     description: >
       Whether to attach a list of generated attestations to the workflow run
@@ -71,6 +90,8 @@ outputs:
     description: 'The ID of the attestation.'
   attestation-url:
     description: 'The URL for the attestation summary.'
+  storage-record-ids:
+    description: 'The IDs of the storage records created for the artifact.'
 
 runs:
   using: node24

dist/606.index.js

@@ -1,7 +1,6 @@
-"use strict";
+export const id = 606;
-exports.id = 606;
+export const ids = [606];
-exports.ids = [606];
+export const modules = {
-exports.modules = {
 
 /***/ 606:
 /***/ ((__unused_webpack___webpack_module__, __webpack_exports__, __webpack_require__) => {
@@ -19,7 +18,7 @@ async function pMap(
 		signal,
 	} = {},
 ) {
-	return new Promise((resolve, reject_) => {
+	return new Promise((resolve_, reject_) => {
 		if (iterable[Symbol.iterator] === undefined && iterable[Symbol.asyncIterator] === undefined) {
 			throw new TypeError(`Expected \`input\` to be either an \`Iterable\` or \`AsyncIterable\`, got (${typeof iterable})`);
 		}
@@ -42,10 +41,24 @@ async function pMap(
 		let currentIndex = 0;
 		const iterator = iterable[Symbol.iterator] === undefined ? iterable[Symbol.asyncIterator]() : iterable[Symbol.iterator]();
 
+		const signalListener = () => {
+			reject(signal.reason);
+		};
+
+		const cleanup = () => {
+			signal?.removeEventListener('abort', signalListener);
+		};
+
+		const resolve = value => {
+			resolve_(value);
+			cleanup();
+		};
+
 		const reject = reason => {
 			isRejected = true;
 			isResolved = true;
 			reject_(reason);
+			cleanup();
 		};
 
 		if (signal) {
@@ -53,9 +66,7 @@ async function pMap(
 				reject(signal.reason);
 			}
 
-			signal.addEventListener('abort', () => {
+			signal.addEventListener('abort', signalListener, {once: true});
-				reject(signal.reason);
-			});
 		}
 
 		const next = async () => {
@@ -203,31 +214,32 @@ function pMapIterable(
 			const iterator = iterable[Symbol.asyncIterator] === undefined ? iterable[Symbol.iterator]() : iterable[Symbol.asyncIterator]();
 
 			const promises = [];
-			let runningMappersCount = 0;
+			let pendingPromisesCount = 0;
 			let isDone = false;
 			let index = 0;
 
 			function trySpawn() {
-				if (isDone || !(runningMappersCount < concurrency && promises.length < backpressure)) {
+				if (isDone || !(pendingPromisesCount < concurrency && promises.length < backpressure)) {
 					return;
 				}
 
+				pendingPromisesCount++;
+
 				const promise = (async () => {
 					const {done, value} = await iterator.next();
 
 					if (done) {
+						pendingPromisesCount--;
 						return {done: true};
 					}
 
-					runningMappersCount++;
-
 					// Spawn if still below concurrency and backpressure limit
 					trySpawn();
 
 					try {
 						const returnValue = await mapper(await value, index++);
 
-						runningMappersCount--;
+						pendingPromisesCount--;
 
 						if (returnValue === pMapSkip) {
 							const index = promises.indexOf(promise);
@@ -242,6 +254,7 @@ function pMapIterable(
 
 						return {done: false, value: returnValue};
 					} catch (error) {
+						pendingPromisesCount--;
 						isDone = true;
 						return {error};
 					}
@@ -284,4 +297,3 @@ const pMapSkip = Symbol('skip');
 /***/ })
 
 };
-;

dist/package.json

@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}

jest.setup.js

@@ -1 +1,3 @@
+import { jest } from '@jest/globals'
+
 process.stdout.write = jest.fn()

package.json

@@ -1,9 +1,10 @@
 {
   "name": "actions/attest",
   "description": "Generate signed attestations for workflow artifacts",
-  "version": "3.0.0",
+  "version": "4.1.0",
   "author": "",
   "private": true,
+  "type": "module",
   "homepage": "https://github.com/actions/attest",
   "repository": {
     "type": "git",
@@ -24,7 +25,7 @@
   },
   "scripts": {
     "bundle": "npm run format:write && npm run package",
-    "ci-test": "jest",
+    "ci-test": "NODE_OPTIONS='--experimental-vm-modules' jest",
     "format:write": "prettier --write **/*.ts",
     "format:check": "prettier --check **/*.ts",
     "lint:eslint": "npx eslint",
@@ -32,12 +33,15 @@
     "lint": "npm run lint:eslint && npm run lint:markdown",
     "package": "ncc build src/index.ts --license licenses.txt",
     "package:watch": "npm run package -- --watch",
-    "test": "jest",
+    "test": "NODE_OPTIONS='--experimental-vm-modules' jest",
     "all": "npm run format:write && npm run lint && npm run test && npm run package"
   },
   "license": "MIT",
   "jest": {
-    "preset": "ts-jest",
+    "preset": "ts-jest/presets/default-esm",
+    "extensionsToTreatAsEsm": [
+      ".ts"
+    ],
     "setupFilesAfterEnv": [
       "./jest.setup.js"
     ],
@@ -56,7 +60,12 @@
       "/dist/"
     ],
     "transform": {
-      "^.+\\.ts$": "ts-jest"
+      "^.+\\.ts$": [
+        "ts-jest",
+        {
+          "useESM": true
+        }
+      ]
     },
     "coverageReporters": [
       "json-summary",
@@ -69,31 +78,32 @@
     ]
   },
   "dependencies": {
-    "@actions/attest": "^1.6.0",
+    "@actions/attest": "^3.2.0",
-    "@actions/core": "^1.11.1",
+    "@actions/core": "^3.0.0",
-    "@actions/github": "^6.0.1",
+    "@actions/github": "^9.0.0",
-    "@actions/glob": "^0.5.0",
+    "@actions/glob": "^0.6.1",
     "@sigstore/oci": "^0.6.0",
     "csv-parse": "^5.6.0"
   },
   "devDependencies": {
-    "@eslint/js": "^9.34.0",
+    "@eslint/js": "^9.39.2",
-    "@sigstore/mock": "^0.11.0",
+    "@jest/globals": "^30.3.0",
+    "@sigstore/mock": "^0.12.0",
     "@types/jest": "^30.0.0",
     "@types/make-fetch-happen": "^10.0.4",
-    "@types/node": "^24.3.0",
+    "@types/node": "^25.6.0",
-    "@vercel/ncc": "^0.38.3",
+    "@vercel/ncc": "^0.38.4",
-    "eslint": "^9.34.0",
+    "eslint": "^9.39.2",
     "eslint-plugin-import": "^2.32.0",
-    "eslint-plugin-jest": "^29.0.1",
+    "eslint-plugin-jest": "^29.15.2",
-    "jest": "^30.0.5",
+    "jest": "^30.3.0",
-    "js-yaml": "^4.1.0",
+    "js-yaml": "^4.1.1",
-    "markdownlint-cli": "^0.45.0",
+    "markdownlint-cli": "^0.48.0",
     "nock": "^13.5.6",
-    "prettier": "^3.6.2",
+    "prettier": "^3.8.3",
-    "ts-jest": "^29.4.1",
+    "ts-jest": "^29.4.9",
-    "typescript": "^5.9.2",
+    "typescript": "^5.9.3",
-    "typescript-eslint": "^8.41.0",
+    "typescript-eslint": "^8.58.2",
-    "undici": "^5.29.0"
+    "undici": "^7.24.4"
   }
 }

src/attest.ts

@@ -1,4 +1,12 @@
-import { Attestation, Predicate, Subject, attest } from '@actions/attest'
+import {
+  Attestation,
+  Predicate,
+  Subject,
+  attest,
+  createStorageRecord
+} from '@actions/attest'
+import * as core from '@actions/core'
+import * as github from '@actions/github'
 import { attachArtifactToImage, getRegistryCredentials } from '@sigstore/oci'
 import { formatSubjectDigest } from './subject'
 
@@ -8,6 +16,7 @@ const OCI_RETRY = 3
 export type SigstoreInstance = 'public-good' | 'github'
 export type AttestResult = Attestation & {
   attestationDigest?: string
+  storageRecordIds?: number[]
 }
 
 export const createAttestation = async (
@@ -16,6 +25,8 @@ export const createAttestation = async (
   opts: {
     sigstoreInstance: SigstoreInstance
     pushToRegistry: boolean
+    createStorageRecord: boolean
+    subjectVersion?: string
     githubToken: string
   }
 ): Promise<AttestResult> => {
@@ -33,10 +44,11 @@ export const createAttestation = async (
   if (subjects.length === 1 && opts.pushToRegistry) {
     const subject = subjects[0]
     const credentials = getRegistryCredentials(subject.name)
+    const subjectDigest = formatSubjectDigest(subject)
     const artifact = await attachArtifactToImage({
       credentials,
       imageName: subject.name,
-      imageDigest: formatSubjectDigest(subject),
+      imageDigest: subjectDigest,
       artifact: Buffer.from(JSON.stringify(attestation.bundle)),
       mediaType: attestation.bundle.mediaType,
       annotations: {
@@ -48,7 +60,80 @@ export const createAttestation = async (
 
     // Add the attestation's digest to the result
     result.attestationDigest = artifact.digest
+
+    // Because creating a storage record requires the 'artifact-metadata:write'
+    // permission, we wrap this in a try/catch to avoid failing the entire
+    // attestation process if the token does not have the correct permissions.
+    if (opts.createStorageRecord) {
+      try {
+        const token = opts.githubToken
+        const isOrg = await repoOwnerIsOrg(token)
+        if (!isOrg) {
+          // The Artifact Metadata Storage Record API is only available to
+          // organizations. So if the repo owner is not an organization,
+          // storage record creation should not be attempted.
+          return result
+        }
+
+        const registryUrl = getRegistryURL(subject.name)
+        const artifactOpts = {
+          name: subject.name,
+          digest: subjectDigest,
+          version: opts.subjectVersion || undefined
+        }
+        const packageRegistryOpts = {
+          registryUrl
+        }
+        const records = await createStorageRecord(
+          artifactOpts,
+          packageRegistryOpts,
+          token
+        )
+
+        if (!records || records.length === 0) {
+          core.warning('No storage records were created.')
+        }
+
+        result.storageRecordIds = records
+      } catch (error) {
+        core.warning(`Failed to create storage record: ${error}`)
+        core.warning(
+          'Please check that the "artifact-metadata:write" permission has been included'
+        )
+      }
+    }
   }
 
   return result
 }
+
+// Call the GET /repos/{owner}/{repo} endpoint to determine if the repo
+// owner is an organization. This is used to determine if storage
+// record creation should be attempted.
+export const repoOwnerIsOrg = async (githubToken: string): Promise<boolean> => {
+  const octokit = github.getOctokit(githubToken)
+  const { data: repo } = await octokit.rest.repos.get({
+    owner: github.context.repo.owner,
+    repo: github.context.repo.repo
+  })
+  return repo.owner?.type === 'Organization'
+}
+
+function getRegistryURL(subjectName: string): string {
+  let url: URL
+
+  try {
+    url = new URL(subjectName)
+  } catch {
+    url = new URL(`https://${subjectName}`)
+  }
+
+  /* istanbul ignore if */
+  if (url.protocol !== 'https:') {
+    throw new Error(
+      `Unsupported protocol ${url.protocol} in subject name ${subjectName}`
+    )
+  }
+
+  return url.origin
+}

src/detect.ts

@@ -0,0 +1,45 @@
+export type AttestationType = 'provenance' | 'sbom' | 'custom'
+
+export type DetectionInputs = {
+  sbomPath: string
+  predicateType: string
+  predicate: string
+  predicatePath: string
+}
+
+export const detectAttestationType = (
+  inputs: DetectionInputs
+): AttestationType => {
+  const { sbomPath, predicateType, predicate, predicatePath } = inputs
+
+  // SBOM mode takes priority
+  if (sbomPath) {
+    return 'sbom'
+  }
+
+  // Custom mode when any predicate inputs are provided
+  if (predicateType || predicate || predicatePath) {
+    return 'custom'
+  }
+
+  // Default to provenance mode
+  return 'provenance'
+}
+
+export const validateAttestationInputs = (inputs: DetectionInputs): void => {
+  const { sbomPath, predicateType, predicate, predicatePath } = inputs
+
+  // Cannot combine sbom-path with predicate inputs
+  if (sbomPath && (predicateType || predicate || predicatePath)) {
+    throw new Error(
+      'Cannot specify sbom-path together with predicate-type, predicate, or predicate-path'
+    )
+  }
+
+  // Custom mode requires predicate-type
+  if ((predicate || predicatePath) && !predicateType) {
+    throw new Error(
+      'predicate-type is required when using predicate or predicate-path'
+    )
+  }
+}

src/index.ts

@@ -9,10 +9,13 @@ const inputs: RunInputs = {
   subjectName: core.getInput('subject-name'),
   subjectDigest: core.getInput('subject-digest'),
   subjectChecksums: core.getInput('subject-checksums'),
+  sbomPath: core.getInput('sbom-path'),
   predicateType: core.getInput('predicate-type'),
   predicate: core.getInput('predicate'),
   predicatePath: core.getInput('predicate-path'),
   pushToRegistry: core.getBooleanInput('push-to-registry'),
+  createStorageRecord: core.getBooleanInput('create-storage-record'),
+  subjectVersion: core.getInput('subject-version'),
   showSummary: core.getBooleanInput('show-summary'),
   githubToken: core.getInput('github-token'),
   // undocumented -- not part of public interface

src/main.ts

@@ -1,11 +1,19 @@
 import * as core from '@actions/core'
 import * as github from '@actions/github'
-import fs from 'fs'
+import fs from 'fs/promises'
 import os from 'os'
 import path from 'path'
 import { AttestResult, SigstoreInstance, createAttestation } from './attest'
+import {
+  AttestationType,
+  DetectionInputs,
+  detectAttestationType,
+  validateAttestationInputs
+} from './detect'
 import { SEARCH_PUBLIC_GOOD_URL } from './endpoints'
 import { PredicateInputs, predicateFromInputs } from './predicate'
+import { generateProvenancePredicate } from './provenance'
+import { generateSBOMPredicate, parseSBOMFromPath } from './sbom'
 import * as style from './style'
 import {
   SubjectInputs,
@@ -13,14 +21,21 @@ import {
   subjectFromInputs
 } from './subject'
 
-import type { Subject } from '@actions/attest'
+import type { Predicate, Subject } from '@actions/attest'
 
 const ATTESTATION_FILE_NAME = 'attestation.json'
 const ATTESTATION_PATHS_FILE_NAME = 'created_attestation_paths.txt'
 
+export type SBOMInputs = {
+  sbomPath: string
+}
+
 export type RunInputs = SubjectInputs &
-  PredicateInputs & {
+  PredicateInputs &
+  SBOMInputs & {
     pushToRegistry: boolean
+    createStorageRecord: boolean
+    subjectVersion: string
     githubToken: string
     showSummary: boolean
     privateSigning: boolean
@@ -57,25 +72,40 @@ export async function run(inputs: RunInputs): Promise<void> {
       )
     }
 
+    // Detect attestation type and validate inputs
+    const detectionInputs: DetectionInputs = {
+      sbomPath: inputs.sbomPath,
+      predicateType: inputs.predicateType,
+      predicate: inputs.predicate,
+      predicatePath: inputs.predicatePath
+    }
+    validateAttestationInputs(detectionInputs)
+    const attestationType = detectAttestationType(detectionInputs)
+    logAttestationType(attestationType)
+
     const subjects = await subjectFromInputs({
       ...inputs,
       downcaseName: inputs.pushToRegistry
     })
-    const predicate = predicateFromInputs(inputs)
 
-    const outputPath = path.join(tempDir(), ATTESTATION_FILE_NAME)
+    // Generate predicate based on attestation type
+    const predicate = await getPredicateForType(attestationType, inputs)
+
+    const outputPath = path.join(await tempDir(), ATTESTATION_FILE_NAME)
     core.setOutput('bundle-path', outputPath)
 
     const att = await createAttestation(subjects, predicate, {
       sigstoreInstance,
       pushToRegistry: inputs.pushToRegistry,
+      createStorageRecord: inputs.createStorageRecord,
+      subjectVersion: inputs.subjectVersion,
       githubToken: inputs.githubToken
     })
 
     logAttestation(subjects, att, sigstoreInstance)
 
     // Write attestation bundle to output file
-    fs.writeFileSync(outputPath, JSON.stringify(att.bundle) + os.EOL, {
+    await fs.writeFile(outputPath, JSON.stringify(att.bundle) + os.EOL, {
       encoding: 'utf-8',
       flag: 'a'
     })
@@ -85,7 +115,7 @@ export async function run(inputs: RunInputs): Promise<void> {
     if (baseDir) {
       const outputSummaryPath = path.join(baseDir, ATTESTATION_PATHS_FILE_NAME)
       // Append the output path to the attestations paths file
-      fs.appendFileSync(outputSummaryPath, outputPath + os.EOL, {
+      await fs.appendFile(outputSummaryPath, outputPath + os.EOL, {
         encoding: 'utf-8',
         flag: 'a'
       })
@@ -101,6 +131,11 @@ export async function run(inputs: RunInputs): Promise<void> {
       core.setOutput('attestation-url', attestationURL(att.attestationID))
     }
 
+    /* istanbul ignore if */
+    if (att.storageRecordIds) {
+      core.setOutput('storage-record-ids', att.storageRecordIds.join(','))
+    }
+
     /* istanbul ignore else */
     if (inputs.showSummary) {
       await logSummary(att)
@@ -150,6 +185,7 @@ const logAttestation = (
   core.info(attestation.certificate)
   core.endGroup()
 
+  /* istanbul ignore if */
   if (attestation.tlogID) {
     core.info(
       style.highlight(
@@ -169,6 +205,12 @@ const logAttestation = (
     core.info(style.highlight('Attestation uploaded to registry'))
     core.info(`${subjects[0].name}@${attestation.attestationDigest}`)
   }
+
+  /* istanbul ignore next */
+  if (attestation.storageRecordIds && attestation.storageRecordIds.length > 0) {
+    core.info(style.highlight('Storage record created'))
+    core.info(`Storage record IDs: ${attestation.storageRecordIds.join(',')}`)
+  }
 }
 
 // Attach summary information to the GitHub Actions run
@@ -184,7 +226,7 @@ const logSummary = async (attestation: AttestResult): Promise<void> => {
   }
 }
 
-const tempDir = (): string => {
+const tempDir = async (): Promise<string> => {
   const basePath = process.env['RUNNER_TEMP']
 
   /* istanbul ignore if */
@@ -192,8 +234,35 @@ const tempDir = (): string => {
     throw new Error('Missing RUNNER_TEMP environment variable')
   }
 
-  return fs.mkdtempSync(path.join(basePath, path.sep))
+  return fs.mkdtemp(path.join(basePath, path.sep))
 }
 
 const attestationURL = (id: string): string =>
   `${github.context.serverUrl}/${github.context.repo.owner}/${github.context.repo.repo}/attestations/${id}`
+
+// Log the detected attestation type
+const logAttestationType = (type: AttestationType): void => {
+  const typeLabels: Record<AttestationType, string> = {
+    provenance: 'Build Provenance',
+    sbom: 'SBOM',
+    custom: 'Custom'
+  }
+  core.info(`Attestation type: ${typeLabels[type]}`)
+}
+
+// Generate predicate based on attestation type
+const getPredicateForType = async (
+  type: AttestationType,
+  inputs: RunInputs
+): Promise<Predicate> => {
+  switch (type) {
+    case 'provenance':
+      return generateProvenancePredicate()
+    case 'sbom': {
+      const sbom = await parseSBOMFromPath(inputs.sbomPath)
+      return generateSBOMPredicate(sbom)
+    }
+    case 'custom':
+      return predicateFromInputs(inputs)
+  }
+}

src/predicate.ts

@@ -1,4 +1,4 @@
-import fs from 'fs'
+import fs from 'fs/promises'
 
 import type { Predicate } from '@actions/attest'
 
@@ -12,7 +12,9 @@ const MAX_PREDICATE_SIZE_BYTES = 16 * 1024 * 1024
 
 // Returns the predicate specified by the action's inputs. The predicate value
 // may be specified as a path to a file or as a string.
-export const predicateFromInputs = (inputs: PredicateInputs): Predicate => {
+export const predicateFromInputs = async (
+  inputs: PredicateInputs
+): Promise<Predicate> => {
   const { predicateType, predicate, predicatePath } = inputs
 
   if (!predicateType) {
@@ -30,18 +32,22 @@ export const predicateFromInputs = (inputs: PredicateInputs): Predicate => {
   let params: string = predicate
 
   if (predicatePath) {
-    if (!fs.existsSync(predicatePath)) {
+    try {
+      await fs.access(predicatePath)
+    } catch {
       throw new Error(`predicate file not found: ${predicatePath}`)
     }
 
+    const stat = await fs.stat(predicatePath)
+
     /* istanbul ignore next */
-    if (fs.statSync(predicatePath).size > MAX_PREDICATE_SIZE_BYTES) {
+    if (stat.size > MAX_PREDICATE_SIZE_BYTES) {
       throw new Error(
         `predicate file exceeds maximum allowed size: ${MAX_PREDICATE_SIZE_BYTES} bytes`
       )
     }
 
-    params = fs.readFileSync(predicatePath, 'utf-8')
+    params = await fs.readFile(predicatePath, 'utf-8')
   } else {
     if (predicate.length > MAX_PREDICATE_SIZE_BYTES) {
       throw new Error(

src/provenance.ts

@@ -0,0 +1,7 @@
+import { buildSLSAProvenancePredicate } from '@actions/attest'
+
+import type { Predicate } from '@actions/attest'
+
+export const generateProvenancePredicate = async (): Promise<Predicate> => {
+  return buildSLSAProvenancePredicate()
+}

src/sbom.ts

@@ -0,0 +1,96 @@
+import fs from 'fs/promises'
+
+import type { Predicate } from '@actions/attest'
+
+export type SBOM = {
+  type: 'spdx' | 'cyclonedx'
+  object: object
+}
+
+// SBOMs cannot exceed 16MB.
+const MAX_SBOM_SIZE_BYTES = 16 * 1024 * 1024
+
+export const parseSBOMFromPath = async (filePath: string): Promise<SBOM> => {
+  let stats
+  try {
+    stats = await fs.stat(filePath)
+  } catch (error) {
+    const err = error as NodeJS.ErrnoException
+    if (err.code === 'ENOENT') {
+      throw new Error('SBOM file not found')
+    }
+    throw error
+  }
+
+  if (stats.size > MAX_SBOM_SIZE_BYTES) {
+    throw new Error(
+      `SBOM file exceeds maximum allowed size: ${MAX_SBOM_SIZE_BYTES} bytes`
+    )
+  }
+
+  const fileContent = await fs.readFile(filePath, 'utf8')
+  const sbom = JSON.parse(fileContent) as object
+
+  if (checkIsSPDX(sbom)) {
+    return { type: 'spdx', object: sbom }
+  } else if (checkIsCycloneDX(sbom)) {
+    return { type: 'cyclonedx', object: sbom }
+  }
+
+  throw new Error(
+    'Unsupported SBOM format. Must be valid SPDX or CycloneDX JSON.'
+  )
+}
+
+const checkIsSPDX = (sbomObject: {
+  spdxVersion?: string
+  SPDXID?: string
+}): boolean => {
+  return !!(sbomObject?.spdxVersion && sbomObject?.SPDXID)
+}
+
+const checkIsCycloneDX = (sbomObject: {
+  bomFormat?: string
+  serialNumber?: string
+  specVersion?: string
+}): boolean => {
+  return !!(
+    sbomObject?.bomFormat &&
+    sbomObject?.serialNumber &&
+    sbomObject?.specVersion
+  )
+}
+
+export const generateSBOMPredicate = (sbom: SBOM): Predicate => {
+  switch (sbom.type) {
+    case 'spdx':
+      return generateSPDXPredicate(sbom.object)
+    case 'cyclonedx':
+      return generateCycloneDXPredicate(sbom.object)
+    default:
+      throw new Error('Unsupported SBOM format')
+  }
+}
+
+// ref: https://github.com/in-toto/attestation/blob/main/spec/predicates/spdx.md
+const generateSPDXPredicate = (sbom: object): Predicate => {
+  const spdxVersion = (sbom as { spdxVersion?: string })?.['spdxVersion']
+  if (!spdxVersion) {
+    throw new Error('Cannot find spdxVersion in the SBOM')
+  }
+
+  const version = spdxVersion.split('-')[1]
+
+  return {
+    type: `https://spdx.dev/Document/v${version}`,
+    params: sbom
+  }
+}
+
+// ref: https://github.com/in-toto/attestation/blob/main/spec/predicates/cyclonedx.md
+const generateCycloneDXPredicate = (sbom: object): Predicate => {
+  return {
+    type: 'https://cyclonedx.org/bom',
+    params: sbom
+  }
+}

src/subject.ts

@@ -2,7 +2,8 @@ import * as glob from '@actions/glob'
 import assert from 'assert'
 import crypto from 'crypto'
 import { parse } from 'csv-parse/sync'
-import fs from 'fs'
+import { createReadStream } from 'fs'
+import fs from 'fs/promises'
 import os from 'os'
 import path from 'path'
 
@@ -64,7 +65,7 @@ export const subjectFromInputs = async (
     case !!subjectDigest:
       return [getSubjectFromDigest(subjectDigest, name)]
     case !!subjectChecksums:
-      return getSubjectFromChecksums(subjectChecksums)
+      return await getSubjectFromChecksums(subjectChecksums)
     /* istanbul ignore next */
     default:
       // This should be unreachable, but TS requires a default case
@@ -93,13 +94,18 @@ const getSubjectFromPath = async (
   // Expand the globbed paths to a list of actual paths
   const paths = await glob.create(subjectPaths).then(async g => g.glob())
 
-  // Filter path list to just the files (not directories)
+  // Filter path list to just the files (not directories), enforcing the maximum
-  const files = paths.filter(p => fs.statSync(p).isFile())
+  const files: string[] = []
-
+  for (const p of paths) {
-  if (files.length > MAX_SUBJECT_COUNT) {
+    const stat = await fs.stat(p)
-    throw new Error(
+    if (stat.isFile()) {
-      `Too many subjects specified. The maximum number of subjects is ${MAX_SUBJECT_COUNT}.`
+      if (files.length >= MAX_SUBJECT_COUNT) {
-    )
+        throw new Error(
+          `Too many subjects specified (>${MAX_SUBJECT_COUNT}). The maximum number of subjects is ${MAX_SUBJECT_COUNT}.`
+        )
+      }
+      files.push(p)
+    }
   }
 
   for (const file of files) {
@@ -142,16 +148,21 @@ const getSubjectFromDigest = (
   }
 }
 
-const getSubjectFromChecksums = (subjectChecksums: string): Subject[] => {
+const getSubjectFromChecksums = async (
-  if (fs.existsSync(subjectChecksums)) {
+  subjectChecksums: string
+): Promise<Subject[]> => {
+  try {
+    await fs.access(subjectChecksums)
     return getSubjectFromChecksumsFile(subjectChecksums)
-  } else {
+  } catch {
     return getSubjectFromChecksumsString(subjectChecksums)
   }
 }
 
-const getSubjectFromChecksumsFile = (checksumsPath: string): Subject[] => {
+const getSubjectFromChecksumsFile = async (
-  const stats = fs.statSync(checksumsPath)
+  checksumsPath: string
+): Promise<Subject[]> => {
+  const stats = await fs.stat(checksumsPath)
   if (!stats.isFile()) {
     throw new Error(`subject checksums file not found: ${checksumsPath}`)
   }
@@ -163,7 +174,7 @@ const getSubjectFromChecksumsFile = (checksumsPath: string): Subject[] => {
     )
   }
 
-  const checksums = fs.readFileSync(checksumsPath, 'utf-8')
+  const checksums = await fs.readFile(checksumsPath, 'utf-8')
   return getSubjectFromChecksumsString(checksums)
 }
 
@@ -195,10 +206,15 @@ const getSubjectFromChecksumsString = (checksums: string): Subject[] => {
       throw new Error(`Invalid digest: ${digest}`)
     }
 
-    subjects.push({
+    const alg = digestAlgorithm(digest)
-      name,
+
-      digest: { [digestAlgorithm(digest)]: digest }
+    // Only add the subject if it is not already in the list (deduplicate by name & digest)
-    })
+    if (!subjects.some(s => s.name === name && s.digest[alg] === digest)) {
+      subjects.push({
+        name,
+        digest: { [alg]: digest }
+      })
+    }
   }
 
   return subjects
@@ -213,7 +229,7 @@ const digestFile = async (
 ): Promise<string> => {
   return new Promise((resolve, reject) => {
     const hash = crypto.createHash(algorithm).setEncoding('hex')
-    fs.createReadStream(filePath)
+    createReadStream(filePath)
       .once('error', reject)
       .pipe(hash)
       .once('finish', () => resolve(hash.read()))

tsconfig.json

@@ -2,9 +2,9 @@
   "$schema": "https://json.schemastore.org/tsconfig",
   "compilerOptions": {
     "target": "ES2022",
-    "module": "NodeNext",
+    "module": "ESNext",
     "rootDir": "./src",
-    "moduleResolution": "NodeNext",
+    "moduleResolution": "Bundler",
     "isolatedModules": true,
     "baseUrl": "./",
     "sourceMap": true,