buildx(imagetools): implement create func with metadata parsing

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

__tests__/buildx/imagetools.test.ts

@@ -0,0 +1,117 @@
+/**
+ * Copyright 2026 actions-toolkit authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {afterEach, describe, expect, it, vi} from 'vitest';
+import fs from 'fs';
+import os from 'os';
+import path from 'path';
+import * as rimraf from 'rimraf';
+
+import {Buildx} from '../../src/buildx/buildx.js';
+import {ImageTools} from '../../src/buildx/imagetools.js';
+import {Context} from '../../src/context.js';
+import {Exec} from '../../src/exec.js';
+
+const tmpDir = fs.mkdtempSync(path.join(process.env.TEMP || os.tmpdir(), 'buildx-imagetools-'));
+const metadataFile = path.join(tmpDir, 'imagetools-metadata.json');
+
+vi.spyOn(Context, 'tmpDir').mockImplementation((): string => {
+  fs.mkdirSync(tmpDir, {recursive: true});
+  return tmpDir;
+});
+
+vi.spyOn(Context, 'tmpName').mockImplementation((): string => {
+  return metadataFile;
+});
+
+afterEach(() => {
+  vi.clearAllMocks();
+  rimraf.sync(tmpDir);
+});
+
+describe('create', () => {
+  it('parses metadata and supports cwd sources', async () => {
+    const getCommand = vi.fn().mockResolvedValue({
+      command: 'docker',
+      args: ['buildx', 'imagetools', 'create']
+    });
+    const buildx = {getCommand} as unknown as Buildx;
+
+    fs.writeFileSync(
+      metadataFile,
+      JSON.stringify({
+        'containerimage.descriptor': {
+          mediaType: 'application/vnd.oci.image.index.v1+json',
+          digest: 'sha256:19ffeab6f8bc9293ac2c3fdf94ebe28396254c993aea0b5a542cfb02e0883fa3',
+          size: 4654
+        },
+        'image.name': 'docker.io/user/app,docker.io/user/app2'
+      })
+    );
+
+    const execSpy = vi.spyOn(Exec, 'getExecOutput').mockResolvedValue({
+      exitCode: 0,
+      stdout: '',
+      stderr: ''
+    });
+
+    const result = await new ImageTools({buildx}).create({
+      sources: ['cwd://descriptor.json', 'docker.io/library/alpine:latest'],
+      tags: ['docker.io/user/app:latest']
+    });
+
+    expect(getCommand).toHaveBeenCalledWith(['imagetools', 'create', '--tag', 'docker.io/user/app:latest', '--metadata-file', metadataFile, '--file', 'descriptor.json', 'docker.io/library/alpine:latest']);
+    expect(execSpy).toHaveBeenCalledWith('docker', ['buildx', 'imagetools', 'create'], {
+      ignoreReturnCode: true,
+      silent: true
+    });
+    expect(result).toEqual({
+      digest: 'sha256:19ffeab6f8bc9293ac2c3fdf94ebe28396254c993aea0b5a542cfb02e0883fa3',
+      descriptor: {
+        mediaType: 'application/vnd.oci.image.index.v1+json',
+        digest: 'sha256:19ffeab6f8bc9293ac2c3fdf94ebe28396254c993aea0b5a542cfb02e0883fa3',
+        size: 4654
+      },
+      imageNames: ['docker.io/user/app', 'docker.io/user/app2']
+    });
+  });
+
+  it('does not parse metadata in dry-run mode', async () => {
+    const getCommand = vi.fn().mockResolvedValue({
+      command: 'docker',
+      args: ['buildx', 'imagetools', 'create']
+    });
+    const buildx = {getCommand} as unknown as Buildx;
+
+    const execSpy = vi.spyOn(Exec, 'getExecOutput').mockResolvedValue({
+      exitCode: 0,
+      stdout: '',
+      stderr: ''
+    });
+
+    const result = await new ImageTools({buildx}).create({
+      sources: ['docker.io/library/alpine:latest'],
+      dryRun: true
+    });
+
+    expect(getCommand).toHaveBeenCalledWith(['imagetools', 'create', '--dry-run', 'docker.io/library/alpine:latest']);
+    expect(execSpy).toHaveBeenCalledWith('docker', ['buildx', 'imagetools', 'create'], {
+      ignoreReturnCode: true,
+      silent: true
+    });
+    expect(result).toBeUndefined();
+  });
+});