ci: Clean up abandoned release branches on PR dismiss (#26342)

.github/scripts/cleanup-release-branch.mjs

@@ -0,0 +1,123 @@
+import fs from 'node:fs/promises';
+import { getOctokit } from '@actions/github';
+import { ensureEnvVar, readPrLabels } from './github-helpers.mjs';
+
+/**
+ * @typedef {PullRequestCheckPass | PullRequestCheckFail} PullRequestCheckResult
+ **/
+
+/**
+ * @typedef PullRequestCheckPass
+ * @property {true} pass
+ * @property {string} baseRef
+ * */
+
+/**
+ * @typedef PullRequestCheckFail
+ * @property {false} pass
+ * @property {string} reason
+ * */
+
+/**
+ * @param {PullRequestCheckResult} pullRequestCheck
+ *
+ * @returns { pullRequestCheck is PullRequestCheckFail }
+ * */
+function pullRequestCheckFailed(pullRequestCheck) {
+	return !pullRequestCheck.pass;
+}
+
+/**
+ * @param {any} pullRequest
+ * @returns {PullRequestCheckResult}
+ */
+export function pullRequestIsDismissedRelease(pullRequest) {
+	if (!pullRequest) {
+		throw new Error('Missing pullRequest in event payload');
+	}
+
+	const baseRef = pullRequest?.base?.ref ?? '';
+	const headRef = pullRequest?.head?.ref ?? '';
+	const merged = Boolean(pullRequest?.merged);
+
+	if (merged) {
+		return { pass: false, reason: 'PR was merged' };
+	}
+
+	// Must match your release PR pattern:
+	//   base: release/<ver>
+	//   head: release-pr/<ver>
+	if (!baseRef.startsWith('release/')) {
+		return { pass: false, reason: `Base ref '${baseRef}' is not release/*` };
+	}
+	if (!headRef.startsWith('release-pr/')) {
+		return { pass: false, reason: `Head ref '${headRef}' is not release-pr/*` };
+	}
+
+	const baseVer = baseRef.slice('release/'.length);
+	const headVer = headRef.slice('release-pr/'.length);
+
+	if (!baseVer || baseVer !== headVer) {
+		return { pass: false, reason: `Version mismatch: base='${baseVer}' head='${headVer}'` };
+	}
+
+	const labelNames = readPrLabels(pullRequest);
+	if (!labelNames.includes('release')) {
+		return {
+			pass: false,
+			reason: `Missing required label 'release' (labels: ${labelNames.join(', ') || '[none]'})`,
+		};
+	}
+
+	return { pass: true, baseRef };
+}
+
+async function main() {
+	const token = ensureEnvVar('GITHUB_TOKEN');
+	const eventPath = ensureEnvVar('GITHUB_EVENT_PATH');
+	const repoFullName = ensureEnvVar('GITHUB_REPOSITORY');
+
+	const [owner, repo] = repoFullName.split('/');
+	if (!owner || !repo) {
+		throw new Error(`Invalid GITHUB_REPOSITORY: '${repoFullName}'`);
+	}
+
+	const rawEventData = await fs.readFile(eventPath, 'utf8');
+	const event = JSON.parse(rawEventData);
+
+	const result = pullRequestIsDismissedRelease(event.pull_request);
+	if (pullRequestCheckFailed(result)) {
+		console.log(`no-op: ${result.reason}`);
+		return;
+	}
+
+	const branch = result.baseRef; // e.g. "release/2.11.0"
+	console.log(`PR qualifies. Deleting branch '${branch}'...`);
+
+	const octokit = getOctokit(token);
+
+	try {
+		await octokit.rest.git.deleteRef({
+			owner,
+			repo,
+			// ref must be "heads/<branch>"
+			ref: `heads/${branch}`,
+		});
+		console.log(`Deleted '${branch}'.`);
+	} catch (err) {
+		// If it was already deleted, treat as success.
+		const status = err?.status;
+		if (status === 404) {
+			console.log(`Branch '${branch}' not found (already deleted).`);
+			return;
+		}
+
+		console.error(err);
+		throw new Error(`Failed to delete '${branch}'.`);
+	}
+}
+
+// only run when executed directly, not when imported by tests
+if (import.meta.url === `file://${process.argv[1]}`) {
+	await main();
+}

.github/scripts/cleanup-release-branch.test.mjs

@@ -0,0 +1,147 @@
+import { describe, it, mock, before } from 'node:test';
+import assert from 'node:assert/strict';
+import { readPrLabels } from './github-helpers.mjs';
+
+/**
+ * Run these tests by running
+ *
+ * node --test --experimental-test-module-mocks ./.github/scripts/cleanup-release-branch.test.mjs
+ * */
+
+// mock.module must be called before the module under test is imported,
+// because static imports are hoisted and resolve before any code runs.
+mock.module('./github-helpers.mjs', {
+	namedExports: {
+		ensureEnvVar: () => {}, // no-op
+		readPrLabels: (pr) => {
+			return readPrLabels(pr);
+		},
+	},
+});
+
+let pullRequestIsDismissedRelease;
+before(async () => {
+	({ pullRequestIsDismissedRelease } = await import('./cleanup-release-branch.mjs'));
+});
+
+describe('pullRequestIsDismissedRelease', () => {
+	it('Recognizes classic dismissed pull request', () => {
+		const pullRequest = {
+			merged: false,
+			labels: ['release'],
+			base: {
+				ref: 'release/2.9.0',
+			},
+			head: {
+				ref: 'release-pr/2.9.0',
+			},
+		};
+
+		/** @type { import('./cleanup-release-branch.mjs').PullRequestCheckResult } */
+		const result = pullRequestIsDismissedRelease(pullRequest);
+
+		assert.equal(result.pass, true);
+		assert.equal(result.reason, undefined);
+	});
+
+	it("Doesn't pass PR with malformed head", () => {
+		const pullRequest = {
+			merged: false,
+			labels: ['release'],
+			base: {
+				ref: 'release/2.9.0',
+			},
+			head: {
+				ref: 'my-fork-release-pr/2.9.0',
+			},
+		};
+
+		/** @type { import('./cleanup-release-branch.mjs').PullRequestCheckResult } */
+		const result = pullRequestIsDismissedRelease(pullRequest);
+
+		assert.equal(result.pass, false);
+		assert.equal(result.reason, `Head ref '${pullRequest.head.ref}' is not release-pr/*`);
+	});
+
+	it("Doesn't pass PR with malformed base", () => {
+		const pullRequest = {
+			merged: false,
+			labels: ['release'],
+			base: {
+				ref: 'master',
+			},
+			head: {
+				ref: 'release-pr/2.9.0',
+			},
+		};
+
+		/** @type { import('./cleanup-release-branch.mjs').PullRequestCheckResult } */
+		const result = pullRequestIsDismissedRelease(pullRequest);
+
+		assert.equal(result.pass, false);
+		assert.equal(result.reason, `Base ref '${pullRequest.base.ref}' is not release/*`);
+	});
+
+	it("Doesn't pass merged PR's", () => {
+		const pullRequest = {
+			merged: true,
+			labels: ['release'],
+			base: {
+				ref: 'release/2.9.0',
+			},
+			head: {
+				ref: 'release-pr/2.9.0',
+			},
+		};
+
+		/** @type { import('./cleanup-release-branch.mjs').PullRequestCheckResult } */
+		const result = pullRequestIsDismissedRelease(pullRequest);
+
+		assert.equal(result.pass, false);
+		assert.equal(result.reason, `PR was merged`);
+	});
+
+	it("Doesn't pass on PR version mismatch", () => {
+		const pullRequest = {
+			merged: false,
+			labels: ['release'],
+			base: {
+				ref: 'release/2.9.0',
+			},
+			head: {
+				ref: 'release-pr/2.9.1',
+			},
+		};
+
+		/** @type { import('./cleanup-release-branch.mjs').PullRequestCheckResult } */
+		const result = pullRequestIsDismissedRelease(pullRequest);
+
+		assert.equal(result.pass, false);
+		assert.equal(
+			result.reason,
+			`Version mismatch: base='${pullRequest.base.ref.replace('release/', '')}' head='${pullRequest.head.ref.replace('release-pr/', '')}'`,
+		);
+	});
+
+	it("Doesn't pass a PR with missing 'release' label", () => {
+		const pullRequest = {
+			merged: false,
+			labels: ['release-pr', 'core-team'],
+			base: {
+				ref: 'release/2.9.0',
+			},
+			head: {
+				ref: 'release-pr/2.9.0',
+			},
+		};
+
+		/** @type { import('./cleanup-release-branch.mjs').PullRequestCheckResult } */
+		const result = pullRequestIsDismissedRelease(pullRequest);
+
+		assert.equal(result.pass, false);
+		assert.equal(
+			result.reason,
+			`Missing required label 'release' (labels: ${pullRequest.labels.join(', ')})`,
+		);
+	});
+});

.github/scripts/github-helpers.mjs

@@ -118,14 +118,18 @@ export function stripReleasePrefixes(tag) {
 }
 
 /**
- * @returns { string[] }
- * */
-export function readPrLabels() {
-	const eventPath = ensureEnvVar('GITHUB_EVENT_PATH');
-
-	const event = JSON.parse(fs.readFileSync(eventPath, 'utf8'));
+ * @param {any} [pullRequest] Optional pull request object. If not provided, reads from GITHUB_EVENT_PATH
+ *
+ * @returns {string[]}
+ */
+export function readPrLabels(pullRequest) {
+	if (!pullRequest) {
+		const eventPath = ensureEnvVar('GITHUB_EVENT_PATH');
+		const event = JSON.parse(fs.readFileSync(eventPath, 'utf8'));
+		pullRequest = event.pull_request;
+	}
 	/** @type { string[] | { name: string }[] } */
-	const labels = event?.pull_request?.labels ?? [];
+	const labels = pullRequest?.labels ?? [];
 
 	return labels.map((l) => (typeof l === 'string' ? l : l?.name)).filter(Boolean);
 }

.github/scripts/package.json

@@ -7,6 +7,7 @@
     "p-limit": "3.1.0",
     "picocolors": "1.0.1",
     "semver": "7.5.4",
-    "tempfile": "5.0.0"
+    "tempfile": "5.0.0",
+    "@actions/github": "9.0.0"
   }
 }