Preserve runtime checkout manifests for post-job hooks

actions/setup/js/checkout_dynamic.cjs

@@ -7,6 +7,8 @@ const { createInterface } = require("readline");
 const { isRepoAllowed } = require("./repo_helpers.cjs");
 const { getSetupTimeoutMs } = require("./child_process_timeouts.cjs");
 
+const NO_OP_STEP = { shell: "bash", run: "true" };
+
 // Only controlled messages may be propagated to workflow failure issues.
 class CheckoutPreparationError extends Error {}
 
@@ -223,12 +225,13 @@ async function prepareCheckouts({ github, getOctokit }, token) {
   // A composite action must contain at least one step, even for an empty scheduled batch.
   try {
     fs.mkdirSync(actionDir, { recursive: true });
+    fs.writeFileSync(path.join(actionDir, ".gitignore"), "*\n");
     fs.writeFileSync(
       path.join(actionDir, "action.yml"),
       JSON.stringify({
         name: "Runtime repository checkout",
         description: "Checkout prevalidated runtime repositories",
-        runs: { using: "composite", steps: steps.length ? steps : [{ shell: "bash", run: "true" }] },
+        runs: { using: "composite", steps: steps.length ? steps : [NO_OP_STEP] },
       })
     );
   } catch (error) {
@@ -394,10 +397,26 @@ async function finish(options = {}) {
   }
   const actionDir = workspacePath(config.workspace, `.gh-aw/checkouts/${config.index}`);
   try {
-    fs.unlinkSync(path.join(actionDir, "action.yml"));
-    fs.rmdirSync(actionDir);
+    // The runner reloads this composite for checkout post hooks; retain a token-free no-op.
+    const temporaryDir = fs.mkdtempSync(path.join(actionDir, ".finalize-"));
+    try {
+      const temporaryManifest = path.join(temporaryDir, "action.yml");
+      fs.writeFileSync(
+        temporaryManifest,
+        JSON.stringify({
+          name: "Runtime repository checkout",
+          description: "Runtime repository checkout finalized",
+          runs: { using: "composite", steps: [NO_OP_STEP] },
+        }),
+        { flag: "wx" }
+      );
+      // Rename atomically to preserve the original on failure without following a manifest symlink.
+      fs.renameSync(temporaryManifest, path.join(actionDir, "action.yml"));
+    } finally {
+      fs.rmSync(temporaryDir, { recursive: true, force: true });
+    }
   } catch (error) {
-    throw new Error("Unable to remove the temporary runtime checkout action", { cause: error });
+    throw new Error("Unable to finalize the temporary runtime checkout action", { cause: error });
   }
   return entries;
 }

actions/setup/js/checkout_dynamic.test.cjs

@@ -63,6 +63,7 @@ describe("runtime repository checkout", () => {
   });
 
   afterEach(() => {
+    vi.restoreAllMocks();
     vi.unstubAllEnvs();
     fs.rmSync(temp, { recursive: true, force: true });
   });
@@ -93,6 +94,69 @@ describe("runtime repository checkout", () => {
     expect(action.runs.steps).toEqual([{ shell: "bash", run: "true" }]);
   });
 
+  it.each([
+    ["empty", ""],
+    ["single", "org/a"],
+    ["multi", "org/a\norg/b"],
+  ])("keeps a token-free no-op composite available for post-job resolution: %s batch", async (_name, repositories) => {
+    vi.stubEnv("GH_AW_DYNAMIC_REPOSITORIES", repositories);
+    const entries = await prepare(runtime);
+    expect(await finish()).toEqual(entries);
+    const manifest = fs.readFileSync(path.join(workspace, ".gh-aw/checkouts/0/action.yml"), "utf8");
+    const action = JSON.parse(manifest);
+    expect(action.name).toBeTruthy();
+    expect(action.description).toBeTruthy();
+    expect(action.runs).toEqual({ using: "composite", steps: [{ shell: "bash", run: "true" }] });
+    expect(manifest).not.toMatch(/token|GH_AW_DYNAMIC|\$\{\{/i);
+  });
+
+  it.each(["writeFileSync", "renameSync"])("preserves the original manifest when replacement fails in %s", async operation => {
+    vi.stubEnv("GH_AW_DYNAMIC_REPOSITORIES", "");
+    await prepare(runtime);
+    const actionDir = path.join(workspace, ".gh-aw/checkouts/0");
+    const manifestPath = path.join(actionDir, "action.yml");
+    const original = fs.readFileSync(manifestPath, "utf8");
+    vi.spyOn(fs, operation).mockImplementation(() => {
+      throw new Error("Injected filesystem failure");
+    });
+    await expect(finish()).rejects.toThrow("Unable to finalize the temporary runtime checkout action");
+    expect(fs.readFileSync(manifestPath, "utf8")).toBe(original);
+    expect(fs.readdirSync(actionDir).sort()).toEqual([".gitignore", "action.yml"]);
+  });
+
+  it("replaces a manifest symlink without modifying its target", async () => {
+    vi.stubEnv("GH_AW_DYNAMIC_REPOSITORIES", "");
+    await prepare(runtime);
+    const manifestPath = path.join(workspace, ".gh-aw/checkouts/0/action.yml");
+    const outside = path.join(temp, "outside.yml");
+    fs.writeFileSync(outside, "unchanged");
+    fs.unlinkSync(manifestPath);
+    fs.symlinkSync(outside, manifestPath);
+    await finish();
+    expect(fs.readFileSync(outside, "utf8")).toBe("unchanged");
+    expect(fs.lstatSync(manifestPath).isSymbolicLink()).toBe(false);
+    expect(JSON.parse(fs.readFileSync(manifestPath, "utf8")).runs).toEqual({ using: "composite", steps: [{ shell: "bash", run: "true" }] });
+  });
+
+  it("keeps runner-owned manifests out of staging, cleanup, and untracked stashes", async () => {
+    const git = args => execFileSync("git", ["-C", workspace, ...args], { encoding: "utf8", stdio: ["ignore", "pipe", "pipe"] }).trim();
+    git(["init", "--initial-branch=main"]);
+    git(["-c", "user.name=Test", "-c", "user.email=test@example.com", "-c", "commit.gpgsign=false", "-c", "core.hooksPath=/dev/null", "commit", "--allow-empty", "-m", "Fixture"]);
+    vi.stubEnv("GH_AW_DYNAMIC_REPOSITORIES", "");
+    await prepare(runtime);
+    await finish();
+    const actionDir = path.join(workspace, ".gh-aw/checkouts/0");
+    git(["add", "-A"]);
+    expect(git(["diff", "--cached", "--name-only"])).toBe("");
+    git(["clean", "-fd"]);
+    const untracked = path.join(workspace, "untracked.txt");
+    fs.writeFileSync(untracked, "stash me");
+    git(["stash", "push", "-u"]);
+    expect(fs.existsSync(untracked)).toBe(false);
+    expect(fs.existsSync(path.join(actionDir, ".gitignore"))).toBe(true);
+    expect(JSON.parse(fs.readFileSync(path.join(actionDir, "action.yml"), "utf8")).runs).toEqual({ using: "composite", steps: [{ shell: "bash", run: "true" }] });
+  });
+
   it.each(["0", "-1", "1.5", "NaN", "Infinity", "9007199254740992", "", " 2 ", "2e1", "2repos", "${{ inputs.max }}"])("rejects invalid max-repos before authenticated reads: %s", async value => {
     vi.stubEnv("GH_AW_DYNAMIC_MAX_REPOS", value);
     await expect(prepare(runtime)).rejects.toThrow("checkout.max-repos must be a positive integer");
@@ -364,7 +428,7 @@ describe("runtime repository checkout", () => {
     expect(runGit.mock.calls[0][1].env).toEqual(options.env);
     expect(runGit.mock.calls[0][1].stdio).toEqual(["ignore", "pipe", "pipe"]);
     expect(options.stdio).toEqual(["ignore", "pipe", "pipe"]);
-    expect(fs.existsSync(path.join(workspace, ".gh-aw/checkouts/0"))).toBe(false);
+    expect(fs.existsSync(path.join(workspace, ".gh-aw/checkouts/0/action.yml"))).toBe(true);
     runGit.mockImplementation(() => {
       throw new Error("secret-token");
     });
@@ -513,7 +577,7 @@ describe("runtime repository checkout", () => {
       expect(fs.readFileSync(path.join(dir, "config"), "utf8")).not.toContain("git-credentials-");
     }
     for (const include of includes) expect(fs.existsSync(include)).toBe(false);
-    expect(fs.existsSync(path.join(workspace, ".gh-aw/checkouts/0"))).toBe(false);
+    expect(fs.existsSync(path.join(workspace, ".gh-aw/checkouts/0/action.yml"))).toBe(true);
   }, 30000);
 
   it.each(["exit 7", "exit 0"])("fails closed when explicit cleanup returns '%s' but credentials remain", async cleaner => {
@@ -601,7 +665,7 @@ describe("runtime repository checkout", () => {
     await finish();
     expect(git(target, ["rev-parse", "origin/feature"])).toBe(git(source, ["rev-parse", "feature"]));
     expect(git(target, ["config", "--local", "--list"])).not.toMatch(/promisor|partialclonefilter|extraheader|secret-token/);
-    expect(fs.existsSync(path.join(workspace, ".gh-aw/checkouts/0"))).toBe(false);
+    expect(fs.existsSync(path.join(workspace, ".gh-aw/checkouts/0/action.yml"))).toBe(true);
   }, 30000);
 
   it("never fetches repository-controlled .gitmodules remotes during finalization, even with recursive fetch configured", async () => {