resolve merge conflicts

README.md

@@ -129,11 +129,12 @@ Start by specifying that you will be using an external configuration file:
     config-file: './.github/dependency-review-config.yml'
 ```
 
-And then create the file in the path you just specified:
+And then create the file in the path you just specified. Please note
+that the **option names in external files use underscores instead of dashes**:
 
 ```yaml
-fail-on-severity: 'critical'
-allow-licenses:
+fail_on_severity: 'critical'
+allow_licenses:
   - 'GPL-3.0'
   - 'BSD-3-Clause'
   - 'MIT'

__tests__/config.test.ts

@@ -2,35 +2,7 @@ import {expect, test, beforeEach} from '@jest/globals'
 import {readConfig} from '../src/config'
 import {getRefs} from '../src/git-refs'
 import * as Utils from '../src/utils'
-
-// GitHub Action inputs come in the form of environment variables
-// with an INPUT prefix (e.g. INPUT_FAIL-ON-SEVERITY)
-function setInput(input: string, value: string): void {
-  process.env[`INPUT_${input.toUpperCase()}`] = value
-}
-
-// We want a clean ENV before each test. We use `delete`
-// since we want `undefined` values and not empty strings.
-function clearInputs(): void {
-  const allowedOptions = [
-    'FAIL-ON-SEVERITY',
-    'FAIL-ON-SCOPES',
-    'ALLOW-LICENSES',
-    'DENY-LICENSES',
-    'ALLOW-GHSAS',
-    'LICENSE-CHECK',
-    'VULNERABILITY-CHECK',
-    'CONFIG-FILE',
-    'BASE-REF',
-    'HEAD-REF',
-    'COMMENT-SUMMARY-IN-PR'
-  ]
-
-  // eslint-disable-next-line github/array-foreach
-  allowedOptions.forEach(option => {
-    delete process.env[`INPUT_${option.toUpperCase()}`]
-  })
-}
+import {setInput, clearInputs} from './test-helpers'
 
 beforeAll(() => {
   jest.spyOn(Utils, 'isSPDXValid').mockReturnValue(true)
@@ -105,60 +77,6 @@ test('it raises an error when no refs are provided and the event is not a pull r
   ).toThrow()
 })
 
-test('it reads an external config file', async () => {
-  setInput('config-file', './__tests__/fixtures/config-allow-sample.yml')
-
-  const config = await readConfig()
-  expect(config.fail_on_severity).toEqual('critical')
-  expect(config.allow_licenses).toEqual(['BSD', 'GPL 2'])
-})
-
-test('raises an error when the config file was not found', async () => {
-  setInput('config-file', 'fixtures/i-dont-exist')
-  await expect(readConfig()).rejects.toThrow(/Unable to fetch/)
-})
-
-test('it parses options from both sources', async () => {
-  setInput('config-file', './__tests__/fixtures/config-allow-sample.yml')
-
-  let config = await readConfig()
-  expect(config.fail_on_severity).toEqual('critical')
-
-  setInput('base-ref', 'a-custom-base-ref')
-  config = await readConfig()
-  expect(config.base_ref).toEqual('a-custom-base-ref')
-})
-
-test('in case of conflicts, the inline config is the source of truth', async () => {
-  setInput('fail-on-severity', 'low')
-  setInput('config-file', './__tests__/fixtures/config-allow-sample.yml') // this will set fail-on-severity to 'critical'
-
-  const config = await readConfig()
-  expect(config.fail_on_severity).toEqual('low')
-})
-
-test('it uses the default values when loading external files', async () => {
-  setInput('config-file', './__tests__/fixtures/no-licenses-config.yml')
-  let config = await readConfig()
-  expect(config.allow_licenses).toEqual(undefined)
-  expect(config.deny_licenses).toEqual(undefined)
-
-  setInput('config-file', './__tests__/fixtures/license-config-sample.yml')
-  config = await readConfig()
-  expect(config.fail_on_severity).toEqual('low')
-})
-
-test('it accepts an external configuration filename', async () => {
-  setInput('config-file', './__tests__/fixtures/no-licenses-config.yml')
-  const config = await readConfig()
-  expect(config.fail_on_severity).toEqual('critical')
-})
-
-test('it raises an error when given an unknown severity in an external config file', async () => {
-  setInput('config-file', './__tests__/fixtures/invalid-severity-config.yml')
-  await expect(readConfig()).rejects.toThrow()
-})
-
 test('it defaults to runtime scope', async () => {
   const config = await readConfig()
   expect(config.fail_on_scopes).toEqual(['runtime'])
@@ -234,16 +152,6 @@ test('it is not possible to disable both checks', async () => {
   )
 })
 
-test('it supports comma-separated lists', async () => {
-  setInput(
-    'config-file',
-    './__tests__/fixtures/inline-license-config-sample.yml'
-  )
-  const config = await readConfig()
-
-  expect(config.allow_licenses).toEqual(['MIT', 'GPL-2.0-only'])
-})
-
 describe('licenses that are not valid SPDX licenses', () => {
   beforeAll(() => {
     jest.spyOn(Utils, 'isSPDXValid').mockReturnValue(false)

__tests__/external-config.test.ts

@@ -0,0 +1,111 @@
+import {expect, test, beforeEach} from '@jest/globals'
+import {readConfig} from '../src/config'
+import * as Utils from '../src/utils'
+import {setInput, clearInputs} from './test-helpers'
+
+const externalConfig = `fail_on_severity: 'high'
+allow_licenses: ['GPL-2.0-only']
+`
+const mockOctokit = {
+  rest: {
+    repos: {
+      getContent: jest.fn().mockReturnValue({data: externalConfig})
+    }
+  }
+}
+
+jest.mock('octokit', () => {
+  return {
+    // eslint-disable-next-line @typescript-eslint/no-extraneous-class
+    Octokit: class {
+      constructor() {
+        return mockOctokit
+      }
+    }
+  }
+})
+
+beforeAll(() => {
+  jest.spyOn(Utils, 'isSPDXValid').mockReturnValue(true)
+})
+
+beforeEach(() => {
+  clearInputs()
+})
+
+test('it reads an external config file', async () => {
+  setInput('config-file', './__tests__/fixtures/config-allow-sample.yml')
+
+  const config = await readConfig()
+  expect(config.fail_on_severity).toEqual('critical')
+  expect(config.allow_licenses).toEqual(['BSD', 'GPL 2'])
+})
+
+test('raises an error when the config file was not found', async () => {
+  setInput('config-file', 'fixtures/i-dont-exist')
+  await expect(readConfig()).rejects.toThrow(/Unable to fetch/)
+})
+
+test('it parses options from both sources', async () => {
+  setInput('config-file', './__tests__/fixtures/config-allow-sample.yml')
+
+  let config = await readConfig()
+  expect(config.fail_on_severity).toEqual('critical')
+
+  setInput('base-ref', 'a-custom-base-ref')
+  config = await readConfig()
+  expect(config.base_ref).toEqual('a-custom-base-ref')
+})
+
+test('in case of conflicts, the inline config is the source of truth', async () => {
+  setInput('fail-on-severity', 'low')
+  setInput('config-file', './__tests__/fixtures/config-allow-sample.yml') // this will set fail-on-severity to 'critical'
+
+  const config = await readConfig()
+  expect(config.fail_on_severity).toEqual('low')
+})
+
+test('it uses the default values when loading external files', async () => {
+  setInput('config-file', './__tests__/fixtures/no-licenses-config.yml')
+  let config = await readConfig()
+  expect(config.allow_licenses).toEqual(undefined)
+  expect(config.deny_licenses).toEqual(undefined)
+
+  setInput('config-file', './__tests__/fixtures/license-config-sample.yml')
+  config = await readConfig()
+  expect(config.fail_on_severity).toEqual('low')
+})
+
+test('it accepts an external configuration filename', async () => {
+  setInput('config-file', './__tests__/fixtures/no-licenses-config.yml')
+  const config = await readConfig()
+  expect(config.fail_on_severity).toEqual('critical')
+})
+
+test('it raises an error when given an unknown severity in an external config file', async () => {
+  setInput('config-file', './__tests__/fixtures/invalid-severity-config.yml')
+  await expect(readConfig()).rejects.toThrow()
+})
+
+test('it supports comma-separated lists', async () => {
+  setInput(
+    'config-file',
+    './__tests__/fixtures/inline-license-config-sample.yml'
+  )
+  const config = await readConfig()
+
+  expect(config.allow_licenses).toEqual(['MIT', 'GPL-2.0-only'])
+})
+
+test('it reads a config file hosted in another repo', async () => {
+  setInput(
+    'config-file',
+    'future-funk/anyone-cualkiera/external-config.yml@main'
+  )
+  setInput('external-repo-token', 'gh_viptoken')
+
+  const config = await readConfig()
+
+  expect(config.fail_on_severity).toEqual('high')
+  expect(config.allow_licenses).toEqual(['GPL-2.0-only'])
+})

__tests__/fixtures/inline-license-config-sample.yml

@@ -1 +1 @@
-allow-licenses: MIT, GPL-2.0-only
+allow-licenses: "MIT, GPL-2.0-only"

__tests__/fixtures/invalid-severity-config.yml

@@ -1,3 +1,3 @@
-fail-on-severity: 'so many zombies'
-deny-licenses:
+fail_on_severity: 'so many zombies'
+deny_licenses:
   - MIT

__tests__/summary.test.ts

@@ -27,6 +27,45 @@ const defaultConfig: ConfigurationOptions = {
   comment_summary_in_pr: true
 }
 
+const changesWithEmptyManifests: Changes = [
+  {
+    change_type: 'added',
+    manifest: '',
+    ecosystem: 'unknown',
+    name: 'castore',
+    version: '0.1.17',
+    package_url: 'pkg:hex/castore@0.1.17',
+    license: null,
+    source_repository_url: null,
+    scope: 'runtime',
+    vulnerabilities: []
+  },
+  {
+    change_type: 'added',
+    manifest: '',
+    ecosystem: 'unknown',
+    name: 'connection',
+    version: '1.1.0',
+    package_url: 'pkg:hex/connection@1.1.0',
+    license: null,
+    source_repository_url: null,
+    scope: 'runtime',
+    vulnerabilities: []
+  },
+  {
+    change_type: 'added',
+    manifest: 'python/dist-info/METADATA',
+    ecosystem: 'pip',
+    name: 'pygments',
+    version: '2.6.1',
+    package_url: 'pkg:pypi/pygments@2.6.1',
+    license: 'BSD-2-Clause',
+    source_repository_url: 'https://github.com/pygments/pygments',
+    scope: 'runtime',
+    vulnerabilities: []
+  }
+]
+
 test('prints headline as h1', () => {
   summary.addSummaryToSummary(
     emptyChanges,
@@ -65,6 +104,22 @@ test('only includes "No license issues found"-message if "vulnerability_check" i
   expect(text).toContain('✅ No license issues found.')
 })
 
+test('groups dependencies with empty manifest paths together', () => {
+  summary.addSummaryToSummary(
+    changesWithEmptyManifests,
+    emptyInvalidLicenseChanges,
+    defaultConfig
+  )
+  summary.addScannedDependencies(changesWithEmptyManifests)
+  const text = core.summary.stringify()
+
+  expect(text).toContain('<summary>Unnamed Manifest</summary>')
+  expect(text).toContain('castore')
+  expect(text).toContain('connection')
+  expect(text).toContain('<summary>python/dist-info/METADATA</summary>')
+  expect(text).toContain('pygments')
+})
+
 test('does not include status section if nothing was found', () => {
   summary.addSummaryToSummary(
     emptyChanges,

__tests__/test-helpers.ts

@@ -0,0 +1,28 @@
+// GitHub Action inputs come in the form of environment variables
+// with an INPUT prefix (e.g. INPUT_FAIL-ON-SEVERITY)
+export function setInput(input: string, value: string): void {
+  process.env[`INPUT_${input.toUpperCase()}`] = value
+}
+
+// We want a clean ENV before each test. We use `delete`
+// since we want `undefined` values and not empty strings.
+export function clearInputs(): void {
+  const allowedOptions = [
+    'FAIL-ON-SEVERITY',
+    'FAIL-ON-SCOPES',
+    'ALLOW-LICENSES',
+    'DENY-LICENSES',
+    'ALLOW-GHSAS',
+    'LICENSE-CHECK',
+    'VULNERABILITY-CHECK',
+    'CONFIG-FILE',
+    'BASE-REF',
+    'HEAD-REF',
+    'COMMENT-SUMMARY-IN-PR'
+  ]
+
+  // eslint-disable-next-line github/array-foreach
+  allowedOptions.forEach(option => {
+    delete process.env[`INPUT_${option.toUpperCase()}`]
+  })
+}

action.yml

@@ -1,3 +1,5 @@
+# Avoid using default values for options here since they will
+# end up overriding external configurations.
 name: 'Dependency Review'
 description: 'Prevent the introduction of dependencies with known vulnerabilities'
 author: 'GitHub'
@@ -9,11 +11,9 @@ inputs:
   fail-on-severity:
     description: Don't block PRs below this severity. Possible values are `low`, `moderate`, `high`, `critical`.
     required: false
-    default: 'low'
   fail-on-scopes:
     description: Dependency scopes to block PRs on. Comma-separated list. Possible values are 'unknown', 'runtime', and 'development' (e.g. "runtime, development")
     required: false
-    default: 'runtime'
   base-ref:
     description: The base git ref to be used for this check. Has a default value when the workflow event is `pull_request` or `pull_request_target`. Must be provided otherwise.
     required: false

dist/index.js

@@ -181,15 +181,28 @@ const githubUtils = __importStar(__nccwpck_require__(3030));
 const retry = __importStar(__nccwpck_require__(6298));
 const schemas_1 = __nccwpck_require__(8774);
 const retryingOctokit = githubUtils.GitHub.plugin(retry.retry);
+const SnapshotWarningsHeader = 'x-github-dependency-graph-snapshot-warnings';
 const octo = new retryingOctokit(githubUtils.getOctokitOptions(core.getInput('repo-token', { required: true })));
 function compare({ owner, repo, baseRef, headRef }) {
     return __awaiter(this, void 0, void 0, function* () {
-        const changes = yield octo.paginate('GET /repos/{owner}/{repo}/dependency-graph/compare/{basehead}', {
+        let snapshot_warnings = '';
+        const changes = yield octo.paginate({
+            method: 'GET',
+            url: '/repos/{owner}/{repo}/dependency-graph/compare/{basehead}',
             owner,
             repo,
             basehead: `${baseRef}...${headRef}`
+        }, response => {
+            if (response.headers[SnapshotWarningsHeader] &&
+                typeof response.headers[SnapshotWarningsHeader] === 'string') {
+                snapshot_warnings = Buffer.from(response.headers[SnapshotWarningsHeader], 'base64').toString('utf-8');
+            }
+            return schemas_1.ChangesSchema.parse(response.data);
+        });
+        return schemas_1.ComparisonResponseSchema.parse({
+            changes,
+            snapshot_warnings
         });
-        return schemas_1.ChangesSchema.parse(changes);
     });
 }
 exports.compare = compare;
@@ -472,12 +485,14 @@ function run() {
         try {
             const config = yield (0, config_1.readConfig)();
             const refs = (0, git_refs_1.getRefs)(config, github.context);
-            const changes = yield dependencyGraph.compare({
+            const comparison = yield dependencyGraph.compare({
                 owner: github.context.repo.owner,
                 repo: github.context.repo.repo,
                 baseRef: refs.base,
                 headRef: refs.head
             });
+            const changes = comparison.changes;
+            const snapshot_warnings = comparison.snapshot_warnings;
             if (!changes) {
                 core.info('No Dependency Changes found. Skipping Dependency Review.');
                 return;
@@ -494,6 +509,9 @@ function run() {
                 licenseExclusions: config.allow_dependencies_licenses
             });
             summary.addSummaryToSummary(vulnerableChanges, invalidLicenseChanges, config);
+            if (snapshot_warnings) {
+                summary.addSnapshotWarnings(snapshot_warnings);
+            }
             if (config.vulnerability_check) {
                 summary.addChangeVulnerabilitiesToSummary(vulnerableChanges, minSeverity);
                 printVulnerabilitiesBlock(vulnerableChanges, minSeverity);
@@ -651,7 +669,7 @@ var __importStar = (this && this.__importStar) || function (mod) {
     return result;
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
-exports.ChangesSchema = exports.ConfigurationOptionsSchema = exports.PullRequestSchema = exports.ChangeSchema = exports.SeveritySchema = exports.SCOPES = exports.SEVERITIES = void 0;
+exports.ComparisonResponseSchema = exports.ChangesSchema = exports.ConfigurationOptionsSchema = exports.PullRequestSchema = exports.ChangeSchema = exports.SeveritySchema = exports.SCOPES = exports.SEVERITIES = void 0;
 const z = __importStar(__nccwpck_require__(3301));
 exports.SEVERITIES = ['critical', 'high', 'moderate', 'low'];
 exports.SCOPES = ['unknown', 'runtime', 'development'];
@@ -718,6 +736,10 @@ exports.ConfigurationOptionsSchema = z
     }
 });
 exports.ChangesSchema = z.array(exports.ChangeSchema);
+exports.ComparisonResponseSchema = z.object({
+    changes: z.array(exports.ChangeSchema),
+    snapshot_warnings: z.string()
+});
 
 
 /***/ }),
@@ -751,7 +773,7 @@ var __importStar = (this && this.__importStar) || function (mod) {
     return result;
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
-exports.addScannedDependencies = exports.addLicensesToSummary = exports.addChangeVulnerabilitiesToSummary = exports.addSummaryToSummary = void 0;
+exports.addSnapshotWarnings = exports.addScannedDependencies = exports.addLicensesToSummary = exports.addChangeVulnerabilitiesToSummary = exports.addSummaryToSummary = void 0;
 const core = __importStar(__nccwpck_require__(2186));
 const utils_1 = __nccwpck_require__(918);
 const icons = {
@@ -912,6 +934,20 @@ function addScannedDependencies(changes) {
     }
 }
 exports.addScannedDependencies = addScannedDependencies;
+function addSnapshotWarnings(warnings) {
+    // For now, we want to ignore warnings that just complain
+    // about missing snapshots on the head SHA. This is a product
+    // decision to avoid presenting warnings to users who simply
+    // don't use snapshots.
+    const ignore_regex = new RegExp(/No.*snapshot.*found.*head.*/, 'i');
+    if (ignore_regex.test(warnings)) {
+        return;
+    }
+    core.summary.addHeading('Snapshot Warnings', 2);
+    core.summary.addQuote(`${icons.warning}: ${warnings}`);
+    core.summary.addRaw('Re-running this action after a short time may resolve the issue. See the documentation for more information and troubleshooting advice.');
+}
+exports.addSnapshotWarnings = addSnapshotWarnings;
 function countLicenseIssues(invalidLicenseChanges) {
     return Object.values(invalidLicenseChanges).reduce((acc, val) => acc + val.length, 0);
 }
@@ -965,7 +1001,9 @@ function groupDependenciesByManifest(changes) {
     var _a;
     const dependencies = new Map();
     for (const change of changes) {
-        const manifestName = change.manifest;
+        // If the manifest is null or empty, give it a name now to avoid
+        // breaking the HTML rendering later
+        const manifestName = change.manifest || 'Unnamed Manifest';
         if (dependencies.get(manifestName) === undefined) {
             dependencies.set(manifestName, []);
         }
@@ -45496,7 +45534,7 @@ var __importStar = (this && this.__importStar) || function (mod) {
     return result;
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
-exports.ChangesSchema = exports.ConfigurationOptionsSchema = exports.PullRequestSchema = exports.ChangeSchema = exports.SeveritySchema = exports.SCOPES = exports.SEVERITIES = void 0;
+exports.ComparisonResponseSchema = exports.ChangesSchema = exports.ConfigurationOptionsSchema = exports.PullRequestSchema = exports.ChangeSchema = exports.SeveritySchema = exports.SCOPES = exports.SEVERITIES = void 0;
 const z = __importStar(__nccwpck_require__(3301));
 exports.SEVERITIES = ['critical', 'high', 'moderate', 'low'];
 exports.SCOPES = ['unknown', 'runtime', 'development'];
@@ -45563,6 +45601,10 @@ exports.ConfigurationOptionsSchema = z
     }
 });
 exports.ChangesSchema = z.array(exports.ChangeSchema);
+exports.ComparisonResponseSchema = z.object({
+    changes: z.array(exports.ChangeSchema),
+    snapshot_warnings: z.string()
+});
 
 
 /***/ }),
@@ -45607,7 +45649,9 @@ function groupDependenciesByManifest(changes) {
     var _a;
     const dependencies = new Map();
     for (const change of changes) {
-        const manifestName = change.manifest;
+        // If the manifest is null or empty, give it a name now to avoid
+        // breaking the HTML rendering later
+        const manifestName = change.manifest || 'Unnamed Manifest';
         if (dependencies.get(manifestName) === undefined) {
             dependencies.set(manifestName, []);
         }

package.json

@@ -32,29 +32,31 @@
     "ansi-styles": "^6.2.1",
     "got": "^12.6.0",
     "nodemon": "^2.0.22",
-    "octokit": "^2.0.14",
+    "octokit": "^2.0.16",
     "packageurl-js": "^1.0.2",
     "spdx-expression-parse": "^3.0.1",
     "spdx-satisfies": "^5.0.1",
-    "yaml": "^2.2.1",
+    "yaml": "^2.3.1",
     "zod": "^3.21.4"
   },
   "devDependencies": {
     "@types/jest": "^27.5.2",
-    "@types/node": "^16.18.23",
+    "@types/node": "^16.18.34",
+    "@typescript-eslint/eslint-plugin": "^5.48.1",
+    "@typescript-eslint/parser": "^5.48.0",
     "@types/spdx-expression-parse": "^3.0.2",
     "@types/spdx-satisfies": "^0.1.0",
-    "@typescript-eslint/eslint-plugin": "^5.57.0",
-    "@typescript-eslint/parser": "^5.57.0",
+    "@typescript-eslint/eslint-plugin": "^5.59.8",
+    "@typescript-eslint/parser": "^5.59.8",
     "@vercel/ncc": "^0.36.1",
     "esbuild-register": "^3.4.2",
-    "eslint": "^8.37.0",
+    "eslint": "^8.41.0",
     "eslint-plugin-github": "^4.7.0",
     "eslint-plugin-jest": "^27.2.1",
     "jest": "^27.5.1",
     "js-yaml": "^4.1.0",
     "nodemon": "^2.0.22",
-    "prettier": "2.8.7",
+    "prettier": "2.8.8",
     "ts-jest": "^27.1.4",
     "typescript": "^4.9.5"
   }

src/dependency-graph.ts

@@ -1,9 +1,14 @@
 import * as core from '@actions/core'
 import * as githubUtils from '@actions/github/lib/utils'
 import * as retry from '@octokit/plugin-retry'
-import {Changes, ChangesSchema} from './schemas'
+import {
+  ChangesSchema,
+  ComparisonResponse,
+  ComparisonResponseSchema
+} from './schemas'
 
 const retryingOctokit = githubUtils.GitHub.plugin(retry.retry)
+const SnapshotWarningsHeader = 'x-github-dependency-graph-snapshot-warnings'
 const octo = new retryingOctokit(
   githubUtils.getOctokitOptions(core.getInput('repo-token', {required: true}))
 )
@@ -18,14 +23,31 @@ export async function compare({
   repo: string
   baseRef: string
   headRef: string
-}): Promise<Changes> {
+}): Promise<ComparisonResponse> {
+  let snapshot_warnings = ''
   const changes = await octo.paginate(
-    'GET /repos/{owner}/{repo}/dependency-graph/compare/{basehead}',
     {
+      method: 'GET',
+      url: '/repos/{owner}/{repo}/dependency-graph/compare/{basehead}',
       owner,
       repo,
       basehead: `${baseRef}...${headRef}`
+    },
+    response => {
+      if (
+        response.headers[SnapshotWarningsHeader] &&
+        typeof response.headers[SnapshotWarningsHeader] === 'string'
+      ) {
+        snapshot_warnings = Buffer.from(
+          response.headers[SnapshotWarningsHeader],
+          'base64'
+        ).toString('utf-8')
+      }
+      return ChangesSchema.parse(response.data)
     }
   )
-  return ChangesSchema.parse(changes)
+  return ComparisonResponseSchema.parse({
+    changes,
+    snapshot_warnings
+  })
 }

src/main.ts

@@ -23,12 +23,14 @@ async function run(): Promise<void> {
 
     const refs = getRefs(config, github.context)
 
-    const changes = await dependencyGraph.compare({
+    const comparison = await dependencyGraph.compare({
       owner: github.context.repo.owner,
       repo: github.context.repo.repo,
       baseRef: refs.base,
       headRef: refs.head
     })
+    const changes = comparison.changes
+    const snapshot_warnings = comparison.snapshot_warnings
 
     if (!changes) {
       core.info('No Dependency Changes found. Skipping Dependency Review.')
@@ -67,6 +69,10 @@ async function run(): Promise<void> {
       config
     )
 
+    if (snapshot_warnings) {
+      summary.addSnapshotWarnings(snapshot_warnings)
+    }
+
     if (config.vulnerability_check) {
       summary.addChangeVulnerabilitiesToSummary(vulnerableChanges, minSeverity)
       printVulnerabilitiesBlock(vulnerableChanges, minSeverity)

src/schemas.ts

@@ -74,9 +74,14 @@ export const ConfigurationOptionsSchema = z
   })
 
 export const ChangesSchema = z.array(ChangeSchema)
+export const ComparisonResponseSchema = z.object({
+  changes: z.array(ChangeSchema),
+  snapshot_warnings: z.string()
+})
 
 export type Change = z.infer<typeof ChangeSchema>
 export type Changes = z.infer<typeof ChangesSchema>
+export type ComparisonResponse = z.infer<typeof ComparisonResponseSchema>
 export type ConfigurationOptions = z.infer<typeof ConfigurationOptionsSchema>
 export type Severity = z.infer<typeof SeveritySchema>
 export type Scope = (typeof SCOPES)[number]

src/summary.ts

@@ -222,6 +222,23 @@ export function addScannedDependencies(changes: Changes): void {
   }
 }
 
+export function addSnapshotWarnings(warnings: string): void {
+  // For now, we want to ignore warnings that just complain
+  // about missing snapshots on the head SHA. This is a product
+  // decision to avoid presenting warnings to users who simply
+  // don't use snapshots.
+  const ignore_regex = new RegExp(/No.*snapshot.*found.*head.*/, 'i')
+  if (ignore_regex.test(warnings)) {
+    return
+  }
+
+  core.summary.addHeading('Snapshot Warnings', 2)
+  core.summary.addQuote(`${icons.warning}: ${warnings}`)
+  core.summary.addRaw(
+    'Re-running this action after a short time may resolve the issue. See the documentation for more information and troubleshooting advice.'
+  )
+}
+
 function countLicenseIssues(
   invalidLicenseChanges: InvalidLicenseChanges
 ): number {

src/utils.ts

@@ -8,7 +8,9 @@ export function groupDependenciesByManifest(
 ): Map<string, Changes> {
   const dependencies: Map<string, Changes> = new Map()
   for (const change of changes) {
-    const manifestName = change.manifest
+    // If the manifest is null or empty, give it a name now to avoid
+    // breaking the HTML rendering later
+    const manifestName = change.manifest || 'Unnamed Manifest'
 
     if (dependencies.get(manifestName) === undefined) {
       dependencies.set(manifestName, [])