From 533b65188de4c99cf50c850927b0a9e45cc07308 Mon Sep 17 00:00:00 2001
From: Jacob Richman <jacob314@gmail.com>
Date: Tue, 3 Mar 2026 15:01:06 -0800
Subject: [PATCH] Cleanup old branches. (#19354)

---
 scripts/cleanup-branches.ts | 180 ++++++++++++++++++++++++++++++++++++
 1 file changed, 180 insertions(+)
 create mode 100644 scripts/cleanup-branches.ts

diff --git a/scripts/cleanup-branches.ts b/scripts/cleanup-branches.ts
new file mode 100644
index 0000000000..cfa4da6e35
--- /dev/null
+++ b/scripts/cleanup-branches.ts
@@ -0,0 +1,180 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { execSync } from 'node:child_process';
+import * as readline from 'node:readline/promises';
+import * as process from 'node:process';
+
+function runCmd(cmd: string): string {
+  return execSync(cmd, {
+    encoding: 'utf-8',
+    stdio: ['pipe', 'pipe', 'ignore'],
+  }).trim();
+}
+
+async function main() {
+  try {
+    runCmd('gh --version');
+  } catch {
+    console.error(
+      'Error: "gh" CLI is required but not installed or not working.',
+    );
+    process.exit(1);
+  }
+
+  try {
+    runCmd('git --version');
+  } catch {
+    console.error('Error: "git" is required.');
+    process.exit(1);
+  }
+
+  console.log('Fetching remote branches from origin...');
+  let allBranchesOutput = '';
+  try {
+    // Also fetch to ensure we have the latest commit dates
+    console.log(
+      'Running git fetch to ensure we have up-to-date commit dates and prune stale branches...',
+    );
+    runCmd('git fetch origin --prune');
+
+    // Get all branches with their commit dates
+    allBranchesOutput = runCmd(
+      "git for-each-ref --format='%(refname:lstrip=3) %(committerdate:unix)' refs/remotes/origin",
+    );
+  } catch {
+    console.error('Failed to fetch branches from origin.');
+    process.exit(1);
+  }
+
+  const THIRTY_DAYS_IN_SECONDS = 30 * 24 * 60 * 60;
+  const now = Math.floor(Date.now() / 1000);
+
+  const remoteBranches: { name: string; lastCommitDate: number }[] =
+    allBranchesOutput
+      .split(/\r?\n/)
+      .map((line) => {
+        const parts = line.split(' ');
+        if (parts.length < 2) return null;
+        const date = parseInt(parts.pop() || '0', 10);
+        const name = parts.join(' ');
+        return { name, lastCommitDate: date };
+      })
+      .filter((b): b is { name: string; lastCommitDate: number } => b !== null);
+
+  console.log(`Found ${remoteBranches.length} branches on origin.`);
+
+  console.log('Fetching open PRs...');
+  let openPrsJson = '[]';
+  try {
+    openPrsJson = runCmd(
+      'gh pr list --state open --limit 5000 --json headRefName',
+    );
+  } catch {
+    console.error('Failed to fetch open PRs.');
+    process.exit(1);
+  }
+
+  const openPrs = JSON.parse(openPrsJson);
+  const openPrBranches = new Set(
+    openPrs.map((pr: { headRefName: string }) => pr.headRefName),
+  );
+
+  const protectedPattern =
+    /^(main|master|next|release[-/].*|hotfix[-/].*|v\d+.*|HEAD|gh-readonly-queue.*)$/;
+
+  const branchesToDelete = remoteBranches.filter((branch) => {
+    if (protectedPattern.test(branch.name)) {
+      return false;
+    }
+    if (openPrBranches.has(branch.name)) {
+      return false;
+    }
+
+    const ageInSeconds = now - branch.lastCommitDate;
+    if (ageInSeconds < THIRTY_DAYS_IN_SECONDS) {
+      return false; // Skip branches pushed to recently
+    }
+
+    return true;
+  });
+
+  if (branchesToDelete.length === 0) {
+    console.log('No remote branches to delete.');
+    return;
+  }
+
+  console.log(
+    '\nThe following remote branches are NOT release branches, have NO active PR, and are OLDER than 30 days:',
+  );
+  console.log(
+    '---------------------------------------------------------------------',
+  );
+  branchesToDelete.forEach((b) => console.log(` - ${b.name}`));
+  console.log(
+    '---------------------------------------------------------------------',
+  );
+  console.log(`Total to delete: ${branchesToDelete.length}`);
+
+  const rl = readline.createInterface({
+    input: process.stdin,
+    output: process.stdout,
+  });
+
+  const answer = await rl.question(
+    `\nDo you want to delete these ${branchesToDelete.length} remote branches from origin? (y/N) `,
+  );
+  rl.close();
+
+  if (answer.toLowerCase() === 'y') {
+    console.log('Deleting remote branches...');
+    // Delete in batches to avoid hitting command line length limits
+    const batchSize = 50;
+    for (let i = 0; i < branchesToDelete.length; i += batchSize) {
+      const batch = branchesToDelete.slice(i, i + batchSize).map((b) => b.name);
+      const branchList = batch.join(' ');
+      console.log(`Deleting remote batch ${Math.floor(i / batchSize) + 1}...`);
+      try {
+        execSync(`git push origin --delete ${branchList}`, {
+          stdio: 'inherit',
+        });
+      } catch {
+        console.warn('Batch failed, trying to delete branches individually...');
+        for (const branch of batch) {
+          try {
+            execSync(`git push origin --delete ${branch}`, {
+              stdio: 'pipe',
+            });
+          } catch (err: unknown) {
+            const error = err as { stderr?: Buffer; message?: string };
+            const stderr = error.stderr?.toString() || '';
+            if (!stderr.includes('remote ref does not exist')) {
+              console.error(
+                `Failed to delete branch "${branch}":`,
+                stderr.trim() || error.message,
+              );
+            }
+          }
+        }
+      }
+    }
+
+    console.log('Cleaning up local tracking branches...');
+    try {
+      execSync('git remote prune origin', { stdio: 'inherit' });
+    } catch {
+      console.error('Failed to prune local tracking branches.');
+    }
+    console.log('Cleanup complete.');
+  } else {
+    console.log('Operation cancelled.');
+  }
+}
+
+main().catch((e) => {
+  console.error(e);
+  process.exit(1);
+});