Copy git hooks during worktree init

cli/src/__tests__/worktree.test.ts

@@ -1,8 +1,9 @@
 import fs from "node:fs";
 import os from "node:os";
 import path from "node:path";
+import { execFileSync } from "node:child_process";
 import { describe, expect, it } from "vitest";
-import { copySeededSecretsKey, rebindWorkspaceCwd } from "../commands/worktree.js";
+import { copyGitHooksToWorktreeGitDir, copySeededSecretsKey, rebindWorkspaceCwd } from "../commands/worktree.js";
 import {
   buildWorktreeConfig,
   buildWorktreeEnvEntries,
@@ -199,4 +200,52 @@ describe("worktree helpers", () => {
       }),
     ).toBeNull();
   });
+
+  it("copies shared git hooks into a linked worktree git dir", () => {
+    const tempRoot = fs.mkdtempSync(path.join(os.tmpdir(), "paperclip-worktree-hooks-"));
+    const repoRoot = path.join(tempRoot, "repo");
+    const worktreePath = path.join(tempRoot, "repo-feature");
+
+    try {
+      fs.mkdirSync(repoRoot, { recursive: true });
+      execFileSync("git", ["init"], { cwd: repoRoot, stdio: "ignore" });
+      execFileSync("git", ["config", "user.email", "test@example.com"], { cwd: repoRoot, stdio: "ignore" });
+      execFileSync("git", ["config", "user.name", "Test User"], { cwd: repoRoot, stdio: "ignore" });
+      fs.writeFileSync(path.join(repoRoot, "README.md"), "# temp\n", "utf8");
+      execFileSync("git", ["add", "README.md"], { cwd: repoRoot, stdio: "ignore" });
+      execFileSync("git", ["commit", "-m", "Initial commit"], { cwd: repoRoot, stdio: "ignore" });
+
+      const sourceHooksDir = path.join(repoRoot, ".git", "hooks");
+      const sourceHookPath = path.join(sourceHooksDir, "pre-commit");
+      const sourceTokensPath = path.join(sourceHooksDir, "forbidden-tokens.txt");
+      fs.writeFileSync(sourceHookPath, "#!/usr/bin/env bash\nexit 0\n", { encoding: "utf8", mode: 0o755 });
+      fs.chmodSync(sourceHookPath, 0o755);
+      fs.writeFileSync(sourceTokensPath, "secret-token\n", "utf8");
+
+      execFileSync("git", ["worktree", "add", "--detach", worktreePath], { cwd: repoRoot, stdio: "ignore" });
+
+      const copied = copyGitHooksToWorktreeGitDir(worktreePath);
+      const worktreeGitDir = execFileSync("git", ["rev-parse", "--git-dir"], {
+        cwd: worktreePath,
+        encoding: "utf8",
+        stdio: ["ignore", "pipe", "ignore"],
+      }).trim();
+      const resolvedSourceHooksDir = fs.realpathSync(sourceHooksDir);
+      const resolvedTargetHooksDir = fs.realpathSync(path.resolve(worktreePath, worktreeGitDir, "hooks"));
+      const targetHookPath = path.join(resolvedTargetHooksDir, "pre-commit");
+      const targetTokensPath = path.join(resolvedTargetHooksDir, "forbidden-tokens.txt");
+
+      expect(copied).toMatchObject({
+        sourceHooksPath: resolvedSourceHooksDir,
+        targetHooksPath: resolvedTargetHooksDir,
+        copied: true,
+      });
+      expect(fs.readFileSync(targetHookPath, "utf8")).toBe("#!/usr/bin/env bash\nexit 0\n");
+      expect(fs.statSync(targetHookPath).mode & 0o111).not.toBe(0);
+      expect(fs.readFileSync(targetTokensPath, "utf8")).toBe("secret-token\n");
+    } finally {
+      execFileSync("git", ["worktree", "remove", "--force", worktreePath], { cwd: repoRoot, stdio: "ignore" });
+      fs.rmSync(tempRoot, { recursive: true, force: true });
+    }
+  });
 });

cli/src/commands/worktree.ts

@@ -1,4 +1,16 @@
-import { chmodSync, copyFileSync, existsSync, mkdirSync, readFileSync, rmSync, writeFileSync } from "node:fs";
+import {
+  chmodSync,
+  copyFileSync,
+  existsSync,
+  mkdirSync,
+  readdirSync,
+  readFileSync,
+  readlinkSync,
+  rmSync,
+  statSync,
+  symlinkSync,
+  writeFileSync,
+} from "node:fs";
 import os from "node:os";
 import path from "node:path";
 import { execFileSync } from "node:child_process";
@@ -80,6 +92,14 @@ type EmbeddedPostgresHandle = {
 type GitWorkspaceInfo = {
   root: string;
   commonDir: string;
+  gitDir: string;
+  hooksPath: string;
+};
+
+type CopiedGitHooksResult = {
+  sourceHooksPath: string;
+  targetHooksPath: string;
+  copied: boolean;
 };
 
 type SeedWorktreeDatabaseResult = {
@@ -162,15 +182,88 @@ function detectGitWorkspaceInfo(cwd: string): GitWorkspaceInfo | null {
       encoding: "utf8",
       stdio: ["ignore", "pipe", "ignore"],
     }).trim();
+    const gitDirRaw = execFileSync("git", ["rev-parse", "--git-dir"], {
+      cwd: root,
+      encoding: "utf8",
+      stdio: ["ignore", "pipe", "ignore"],
+    }).trim();
+    const hooksPathRaw = execFileSync("git", ["rev-parse", "--git-path", "hooks"], {
+      cwd: root,
+      encoding: "utf8",
+      stdio: ["ignore", "pipe", "ignore"],
+    }).trim();
     return {
       root: path.resolve(root),
       commonDir: path.resolve(root, commonDirRaw),
+      gitDir: path.resolve(root, gitDirRaw),
+      hooksPath: path.resolve(root, hooksPathRaw),
     };
   } catch {
     return null;
   }
 }
 
+function copyDirectoryContents(sourceDir: string, targetDir: string): boolean {
+  if (!existsSync(sourceDir)) return false;
+
+  const entries = readdirSync(sourceDir, { withFileTypes: true });
+  if (entries.length === 0) return false;
+
+  mkdirSync(targetDir, { recursive: true });
+
+  let copied = false;
+  for (const entry of entries) {
+    const sourcePath = path.resolve(sourceDir, entry.name);
+    const targetPath = path.resolve(targetDir, entry.name);
+
+    if (entry.isDirectory()) {
+      mkdirSync(targetPath, { recursive: true });
+      copyDirectoryContents(sourcePath, targetPath);
+      copied = true;
+      continue;
+    }
+
+    if (entry.isSymbolicLink()) {
+      rmSync(targetPath, { recursive: true, force: true });
+      symlinkSync(readlinkSync(sourcePath), targetPath);
+      copied = true;
+      continue;
+    }
+
+    copyFileSync(sourcePath, targetPath);
+    try {
+      chmodSync(targetPath, statSync(sourcePath).mode & 0o777);
+    } catch {
+      // best effort
+    }
+    copied = true;
+  }
+
+  return copied;
+}
+
+export function copyGitHooksToWorktreeGitDir(cwd: string): CopiedGitHooksResult | null {
+  const workspace = detectGitWorkspaceInfo(cwd);
+  if (!workspace) return null;
+
+  const sourceHooksPath = workspace.hooksPath;
+  const targetHooksPath = path.resolve(workspace.gitDir, "hooks");
+
+  if (sourceHooksPath === targetHooksPath) {
+    return {
+      sourceHooksPath,
+      targetHooksPath,
+      copied: false,
+    };
+  }
+
+  return {
+    sourceHooksPath,
+    targetHooksPath,
+    copied: copyDirectoryContents(sourceHooksPath, targetHooksPath),
+  };
+}
+
 export function rebindWorkspaceCwd(input: {
   sourceRepoRoot: string;
   targetRepoRoot: string;
@@ -493,6 +586,7 @@ export async function worktreeInitCommand(opts: WorktreeInitOptions): Promise<vo
   mergePaperclipEnvEntries(buildWorktreeEnvEntries(paths), paths.envPath);
   ensureAgentJwtSecret(paths.configPath);
   loadPaperclipEnvFile(paths.configPath);
+  const copiedGitHooks = copyGitHooksToWorktreeGitDir(cwd);
 
   let seedSummary: string | null = null;
   let reboundWorkspaceSummary: SeedWorktreeDatabaseResult["reboundWorkspaces"] = [];
@@ -527,6 +621,11 @@ export async function worktreeInitCommand(opts: WorktreeInitOptions): Promise<vo
   p.log.message(pc.dim(`Isolated home: ${paths.homeDir}`));
   p.log.message(pc.dim(`Instance: ${paths.instanceId}`));
   p.log.message(pc.dim(`Server port: ${serverPort} | DB port: ${databasePort}`));
+  if (copiedGitHooks?.copied) {
+    p.log.message(
+      pc.dim(`Mirrored git hooks: ${copiedGitHooks.sourceHooksPath} -> ${copiedGitHooks.targetHooksPath}`),
+    );
+  }
   if (seedSummary) {
     p.log.message(pc.dim(`Seed mode: ${seedMode}`));
     p.log.message(pc.dim(`Seed snapshot: ${seedSummary}`));

doc/DEVELOPING.md

@@ -138,6 +138,7 @@ This command:
 
 - writes repo-local files at `.paperclip/config.json` and `.paperclip/.env`
 - creates an isolated instance under `~/.paperclip-worktrees/instances/<worktree-id>/`
+- when run inside a linked git worktree, mirrors the effective git hooks into that worktree's private git dir
 - picks a free app port and embedded PostgreSQL port
 - by default seeds the isolated DB in `minimal` mode from your main instance via a logical SQL snapshot