Add pre/post workflow hook support to build system

.vscode/settings.json

@@ -4,5 +4,8 @@
   "editor.defaultFormatter": "oxc.oxc-vscode",
   "editor.codeActionsOnSave": {
     "source.fixAll.oxc": "always"
+  },
+  "[typescript]": {
+    "editor.defaultFormatter": "oxc.oxc-vscode"
   }
 }

README.md

@@ -17,12 +17,12 @@ Examples:
 
 ```yaml
 steps:
-  - uses: elastic/github-actions/my-action@v1.0.0
+  - uses: elastic/github-actions/litellm-token@v2.1.1
 ```
 
 ```yaml
 steps:
-  - uses: elastic/github-actions/my-action@abc123def4567890abc123def4567890abc123de # v1.0.0
+  - uses: elastic/github-actions/litellm-token@f443b600d91635bebf5b0d9ebc620189c0d6fba5 # v2.1.1
 ```
 
 The `@<ref>` portion is always a repository ref. That means a tag, branch, or SHA points to a
@@ -34,8 +34,8 @@ that commit.
 Because refs are repository-wide, action usage looks path-scoped but versioning is commit-scoped.
 In practice, this means:
 
-- `elastic/github-actions/my-action@v1.0.0` uses the `my-action/` directory from
-  the repo tag `v1.0.0`
+- `elastic/github-actions/litellm-token@v2.1.1` uses the `litellm-token/` directory from
+  the repo tag `v2.1.1`
 - `elastic/github-actions/another-action@v3.0.0` would use the `another-action/`
   directory from the repo tag `v3.0.0`
 - SHA pinning is supported and recommended when consumers want an immutable reference
@@ -47,12 +47,12 @@ jobs:
   first_job:
     runs-on: ubuntu-latest
     steps:
-      - uses: elastic/github-actions/action-one@abc123
+      - uses: elastic/github-actions/litellm-token@abc123 # v3.1.0
 
   second_job:
     runs-on: ubuntu-latest
     steps:
-      - uses: elastic/github-actions/action-two@def456
+      - uses: elastic/github-actions/action-two@def456 # v3.0.0
 ```
 
 ## Development
@@ -80,8 +80,12 @@ my-action/
   action.yml
   src/
     index.ts
+    pre.ts      # optional
+    post.ts     # optional
   dist/
     index.js
+    pre.js      # generated when src/pre.ts exists
+    post.js     # generated when src/post.ts exists
     licenses.txt
 ```
 
@@ -94,6 +98,8 @@ description: Example action layout for this repository
 runs:
   using: node24
   main: dist/index.js
+  pre: dist/pre.js
+  post: dist/post.js
 ```
 
 Example usage after release:
@@ -117,7 +123,25 @@ artifact:
 CI installs dependencies with `pnpm install --frozen-lockfile`, so changes that require lockfile
 updates must include an updated `pnpm-lock.yaml`.
 
-The build treats any **top-level directory** that contains an `action.yml` as an action and builds it with `@vercel/ncc`. `src/index.ts` is the required entrypoint.
+The build treats any **top-level directory** that contains an `action.yml` as an action and builds it with `@vercel/ncc`.
+
+Build assumptions for root-managed actions:
+
+- `src/index.ts` is required and always builds to `dist/index.js`
+- `src/pre.ts` is optional and, when present, builds to `dist/pre.js`
+- `src/post.ts` is optional and, when present, builds to `dist/post.js`
+- `pnpm build` deletes each action's existing `dist/` directory before rebuilding generated output
+- `dist/licenses.txt` is generated from the main bundle build
+
+If an action declares JavaScript lifecycle hooks in `action.yml`, they should follow the same output convention:
+
+```yaml
+runs:
+  using: node24
+  main: dist/index.js
+  pre: dist/pre.js
+  post: dist/post.js
+```
 
 ### Release tags and floating majors
 

scripts/build-actions.test.ts

@@ -4,9 +4,11 @@ import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 
 vi.mock('node:fs');
 
-const { getActionDirs, runBuildActions } = await import('./build-actions.ts');
+const { getActionDirs, runBuildActions } = await import('./build-actions');
 
 const rootDir = '/repo';
+const log = vi.fn();
+const error = vi.fn();
 
 function seedFs(files: Record<string, string>): void {
   vol.fromJSON(files, rootDir);
@@ -36,14 +38,11 @@ describe('getActionDirs', () => {
 
 describe('runBuildActions', () => {
   it('returns an error when ncc is unavailable', () => {
-    const error = vi.fn();
-
     expect(runBuildActions({ rootDir, error })).toBe(1);
     expect(error).toHaveBeenCalledWith('ncc is not installed. Run pnpm install before building actions.');
   });
 
   it('skips building when no root-managed actions exist', () => {
-    const log = vi.fn();
     seedFs({
       '/repo/node_modules/@vercel/ncc/dist/ncc/cli.js': '',
     });
@@ -52,12 +51,13 @@ describe('runBuildActions', () => {
     expect(log).toHaveBeenCalledWith('No root-managed actions found. Skipping build.');
   });
 
-  it('builds actions with ncc', () => {
-    const log = vi.fn();
+  it('builds the main action bundle', () => {
     const actionDir = path.join(rootDir, 'my-action');
-    const spawn = vi.fn((_, __, options: { cwd: string }) => {
+    const spawn = vi.fn((_, args: string[], options: { cwd: string }) => {
+      const outputDir = path.join(options.cwd, args[args.indexOf('--out') + 1]!);
       seedFs({
-        [`${options.cwd}/dist/index.js`]: 'module.exports = {};',
+        [path.join(outputDir, 'index.js')]: 'module.exports = "main";',
+        [path.join(outputDir, 'licenses.txt')]: 'license text',
       });
 
       return { status: 0 };
@@ -70,14 +70,65 @@ describe('runBuildActions', () => {
     });
 
     expect(runBuildActions({ rootDir, log, spawn })).toBe(0);
-    expect(log).toHaveBeenCalledWith('Building my-action');
     expect(spawn).toHaveBeenCalledOnce();
-    expect(vol.existsSync(path.join(actionDir, 'dist', 'index.js'))).toBe(true);
+    expect(vol.readFileSync(path.join(actionDir, 'dist', 'index.js'), 'utf8')).toContain('main');
+    expect(vol.readFileSync(path.join(actionDir, 'dist', 'licenses.txt'), 'utf8')).toContain('license text');
   });
 
-  it('fails when an action is missing src/index.ts', () => {
-    const error = vi.fn();
+  it('builds optional pre and post bundles to flat dist files', () => {
+    const actionDir = path.join(rootDir, 'my-action');
+    const spawn = vi.fn((_, args: string[], options: { cwd: string }) => {
+      const outputDir = path.join(options.cwd, args[args.indexOf('--out') + 1]!);
+      const entryFile = args[2];
+      const writes: Record<string, string> = {
+        [path.join(outputDir, 'index.js')]: `module.exports = ${JSON.stringify(entryFile)};`,
+      };
+
+      if (args.includes('--license')) {
+        writes[path.join(outputDir, 'licenses.txt')] = 'license text';
+      }
+
+      seedFs(writes);
+      return { status: 0 };
+    });
 
+    seedFs({
+      '/repo/node_modules/@vercel/ncc/dist/ncc/cli.js': '',
+      '/repo/my-action/action.yml': '',
+      '/repo/my-action/src/index.ts': 'export {};',
+      '/repo/my-action/src/pre.ts': 'export {};',
+      '/repo/my-action/src/post.ts': 'export {};',
+      '/repo/my-action/dist/pre.js': 'stale pre',
+      '/repo/my-action/dist/post.js': 'stale post',
+    });
+
+    expect(runBuildActions({ rootDir, log, spawn })).toBe(0);
+    expect(spawn).toHaveBeenCalledTimes(3);
+    expect(spawn).toHaveBeenNthCalledWith(
+      1,
+      expect.any(String),
+      expect.arrayContaining(['src/index.ts', '--out', 'dist', '--license', 'licenses.txt']),
+      expect.objectContaining({ cwd: actionDir }),
+    );
+    expect(spawn).toHaveBeenNthCalledWith(
+      2,
+      expect.any(String),
+      expect.arrayContaining(['src/pre.ts', '--out', path.join('dist', 'pre')]),
+      expect.objectContaining({ cwd: actionDir }),
+    );
+    expect(spawn).toHaveBeenNthCalledWith(
+      3,
+      expect.any(String),
+      expect.arrayContaining(['src/post.ts', '--out', path.join('dist', 'post')]),
+      expect.objectContaining({ cwd: actionDir }),
+    );
+    expect(vol.readFileSync(path.join(actionDir, 'dist', 'pre.js'), 'utf8')).toContain('src/pre.ts');
+    expect(vol.readFileSync(path.join(actionDir, 'dist', 'post.js'), 'utf8')).toContain('src/post.ts');
+    expect(vol.existsSync(path.join(actionDir, 'dist', 'pre'))).toBe(false);
+    expect(vol.existsSync(path.join(actionDir, 'dist', 'post'))).toBe(false);
+  });
+
+  it('fails when an action is missing src/index.ts', () => {
     seedFs({
       '/repo/node_modules/@vercel/ncc/dist/ncc/cli.js': '',
       '/repo/my-action/action.yml': '',

scripts/build-actions.ts

@@ -1,5 +1,5 @@
 import { spawnSync, type SpawnSyncReturns } from 'node:child_process';
-import { existsSync, readdirSync } from 'node:fs';
+import { existsSync, readdirSync, renameSync, rmSync } from 'node:fs';
 import path from 'node:path';
 import process from 'node:process';
 import { fileURLToPath } from 'node:url';
@@ -22,6 +22,12 @@ type RunBuildActionsOptions = {
   error?: (message: string) => void;
 };
 
+type HookBuild = {
+  sourceFile: string;
+  outputDir: string;
+  finalFile: string;
+};
+
 export function getActionDirs(rootDir: string): string[] {
   return readdirSync(rootDir, { withFileTypes: true })
     .filter((entry) => entry.isDirectory())
@@ -51,17 +57,31 @@ export function runBuildActions({
   }
 
   for (const actionDir of actionDirs) {
-    const entryFile = path.join(actionDir, 'src', 'index.ts');
     const relativeActionDir = path.relative(rootDir, actionDir);
+    const mainSourceFile = path.join(actionDir, 'src', 'index.ts');
+    const hookBuilds: HookBuild[] = [
+      {
+        sourceFile: path.join(actionDir, 'src', 'pre.ts'),
+        outputDir: path.join(actionDir, 'dist', 'pre'),
+        finalFile: path.join(actionDir, 'dist', 'pre.js'),
+      },
+      {
+        sourceFile: path.join(actionDir, 'src', 'post.ts'),
+        outputDir: path.join(actionDir, 'dist', 'post'),
+        finalFile: path.join(actionDir, 'dist', 'post.js'),
+      },
+    ];
 
-    if (!existsSync(entryFile)) {
+    if (!existsSync(mainSourceFile)) {
       error(`${relativeActionDir} is missing src/index.ts.`);
       return 1;
     }
 
     log(`Building ${relativeActionDir}`);
 
-    const result = spawn(
+    rmSync(path.join(actionDir, 'dist'), { recursive: true, force: true });
+
+    const mainResult = spawn(
       process.execPath,
       [
         nccCliPath,
@@ -80,8 +100,38 @@ export function runBuildActions({
       },
     );
 
-    if (result.status !== 0) {
-      return result.status ?? 1;
+    if (mainResult.status !== 0) {
+      return mainResult.status ?? 1;
+    }
+
+    for (const hookBuild of hookBuilds) {
+      if (!existsSync(hookBuild.sourceFile)) {
+        continue;
+      }
+
+      const result = spawn(
+        process.execPath,
+        [
+          nccCliPath,
+          'build',
+          path.relative(actionDir, hookBuild.sourceFile),
+          '--out',
+          path.relative(actionDir, hookBuild.outputDir),
+          '--target',
+          'es2022',
+        ],
+        {
+          cwd: actionDir,
+          stdio: 'inherit',
+        },
+      );
+
+      if (result.status !== 0) {
+        return result.status ?? 1;
+      }
+
+      renameSync(path.join(hookBuild.outputDir, 'index.js'), hookBuild.finalFile);
+      rmSync(hookBuild.outputDir, { recursive: true, force: true });
     }
   }
 

tsconfig.json

@@ -1,6 +1,5 @@
 {
   "compilerOptions": {
-    "allowImportingTsExtensions": true,
     "esModuleInterop": true,
     "module": "ESNext",
     "moduleResolution": "Bundler",