fix: exclude .claude-pr snapshot from git staging (#1277)

src/github/operations/restore-config.ts

@@ -1,5 +1,13 @@
 import { execFileSync } from "child_process";
-import { cpSync, existsSync, rmSync } from "fs";
+import {
+  appendFileSync,
+  cpSync,
+  existsSync,
+  mkdirSync,
+  readFileSync,
+  rmSync,
+} from "fs";
+import { dirname } from "path";
 
 // Paths that are both PR-controllable and read from cwd at CLI startup.
 //
@@ -20,6 +28,30 @@ const SENSITIVE_PATHS = [
   ".husky",
 ];
 
+const CLAUDE_PR_EXCLUDE_PATTERN = "/.claude-pr/";
+
+function ensureClaudePrExcludedFromGit(): void {
+  const excludePath = execFileSync(
+    "git",
+    ["rev-parse", "--git-path", "info/exclude"],
+    { encoding: "utf8" },
+  ).trim();
+
+  const excludeContents = existsSync(excludePath)
+    ? readFileSync(excludePath, "utf8")
+    : "";
+
+  if (excludeContents.split(/\r?\n/).includes(CLAUDE_PR_EXCLUDE_PATTERN)) {
+    return;
+  }
+
+  mkdirSync(dirname(excludePath), { recursive: true });
+
+  const prefix =
+    excludeContents.length === 0 || excludeContents.endsWith("\n") ? "" : "\n";
+  appendFileSync(excludePath, `${prefix}${CLAUDE_PR_EXCLUDE_PATTERN}\n`);
+}
+
 /**
  * Restores security-sensitive config paths from the PR base branch.
  *
@@ -59,8 +91,9 @@ export function restoreConfigFromBase(baseBranch: string): void {
   }
   if (existsSync(".claude-pr")) {
     console.log(
-      "Preserved PR's sensitive paths → .claude-pr/ for review agents (not executed)",
+      "Preserved PR's sensitive paths -> .claude-pr/ for review agents (not executed)",
     );
+    ensureClaudePrExcludedFromGit();
   }
 
   // Delete PR-controlled versions BEFORE fetching so the attacker-controlled

test/restore-config.test.ts

@@ -0,0 +1,169 @@
+import { afterEach, beforeEach, describe, expect, test } from "bun:test";
+import { execFileSync } from "child_process";
+import {
+  existsSync,
+  mkdtempSync,
+  mkdirSync,
+  readFileSync,
+  rmSync,
+  writeFileSync,
+} from "fs";
+import { dirname, isAbsolute, join } from "path";
+import { restoreConfigFromBase } from "../src/github/operations/restore-config";
+
+const CLAUDE_PR_EXCLUDE_PATTERN = "/.claude-pr/";
+
+describe("restoreConfigFromBase", () => {
+  let originalCwd: string;
+  let tempDir = "";
+  let repoDir: string;
+  let remoteDir: string;
+
+  beforeEach(() => {
+    originalCwd = process.cwd();
+    tempDir = mkdtempSync(join("/tmp", "restore-config-"));
+    repoDir = join(tempDir, "repo");
+    remoteDir = join(tempDir, "origin.git");
+
+    execFileSync("git", ["init", "--bare", remoteDir], { stdio: "pipe" });
+    execFileSync("git", ["init", repoDir], { stdio: "pipe" });
+    git(["checkout", "-b", "main"]);
+    git(["config", "user.email", "test@example.com"]);
+    git(["config", "user.name", "Test User"]);
+
+    writeRepoFile("CLAUDE.md", "base claude instructions\n");
+    writeRepoFile(
+      ".claude/settings.json",
+      `${JSON.stringify({ source: "base" })}\n`,
+    );
+    writeRepoFile("src/index.ts", "export const base = true;\n");
+
+    git(["add", "CLAUDE.md", ".claude/settings.json", "src/index.ts"]);
+    git(["commit", "-m", "base config"]);
+    git(["remote", "add", "origin", remoteDir]);
+    git(["push", "-u", "origin", "main"]);
+
+    git(["checkout", "-b", "pr"]);
+    writeRepoFile("CLAUDE.md", "pr claude instructions\n");
+    writeRepoFile(
+      ".claude/settings.json",
+      `${JSON.stringify({ source: "pr" })}\n`,
+    );
+    git(["add", "CLAUDE.md", ".claude/settings.json"]);
+    git(["commit", "-m", "pr config"]);
+
+    process.chdir(repoDir);
+  });
+
+  afterEach(() => {
+    process.chdir(originalCwd);
+    if (tempDir) {
+      rmSync(tempDir, { recursive: true, force: true });
+    }
+  });
+
+  test("preserves PR sensitive files while excluding .claude-pr from broad staging", () => {
+    const gitignoreExistedBefore = existsRepoFile(".gitignore");
+    const gitignoreContentsBefore = gitignoreExistedBefore
+      ? readRepoFile(".gitignore")
+      : "";
+
+    restoreConfigFromBase("main");
+
+    expect(readRepoFile(".claude-pr/CLAUDE.md")).toBe(
+      "pr claude instructions\n",
+    );
+    expect(readRepoFile(".claude-pr/.claude/settings.json")).toBe(
+      `${JSON.stringify({ source: "pr" })}\n`,
+    );
+    expect(readRepoFile("CLAUDE.md")).toBe("base claude instructions\n");
+    expect(readRepoFile(".claude/settings.json")).toBe(
+      `${JSON.stringify({ source: "base" })}\n`,
+    );
+    expect(git(["check-ignore", ".claude-pr/CLAUDE.md"]).trim()).toBe(
+      ".claude-pr/CLAUDE.md",
+    );
+    expect(countClaudePrExcludeEntries()).toBe(1);
+
+    restoreConfigFromBase("main");
+
+    expect(countClaudePrExcludeEntries()).toBe(1);
+    expect(existsRepoFile(".gitignore")).toBe(gitignoreExistedBefore);
+    if (gitignoreExistedBefore) {
+      expect(readRepoFile(".gitignore")).toBe(gitignoreContentsBefore);
+    }
+
+    writeRepoFile("src/fix.ts", "export const fix = true;\n");
+    git(["add", "-A"]);
+
+    const stagedFiles = git(["diff", "--cached", "--name-only"])
+      .trim()
+      .split(/\r?\n/)
+      .filter(Boolean);
+    expect(stagedFiles).toContain("src/fix.ts");
+    expect(stagedFiles.some((file) => file.startsWith(".claude-pr/"))).toBe(
+      false,
+    );
+
+    git(["commit", "-m", "apply fix"]);
+
+    const committedFiles = git(["show", "--name-only", "--format=", "HEAD"])
+      .trim()
+      .split(/\r?\n/)
+      .filter(Boolean);
+    expect(committedFiles).toContain("src/fix.ts");
+    expect(committedFiles.some((file) => file.startsWith(".claude-pr/"))).toBe(
+      false,
+    );
+    expect(existsRepoFile(".gitignore")).toBe(gitignoreExistedBefore);
+    if (gitignoreExistedBefore) {
+      expect(readRepoFile(".gitignore")).toBe(gitignoreContentsBefore);
+    }
+  });
+
+  test("does not modify an existing .gitignore", () => {
+    writeRepoFile(".gitignore", "node_modules\n");
+    git(["add", ".gitignore"]);
+    git(["commit", "-m", "add gitignore"]);
+
+    const gitignoreBefore = readRepoFile(".gitignore");
+
+    restoreConfigFromBase("main");
+
+    expect(readRepoFile(".gitignore")).toBe(gitignoreBefore);
+    expect(countClaudePrExcludeEntries()).toBe(1);
+  });
+
+  function git(args: string[]): string {
+    return execFileSync("git", args, {
+      cwd: repoDir,
+      encoding: "utf8",
+      stdio: ["ignore", "pipe", "pipe"],
+    });
+  }
+
+  function writeRepoFile(path: string, contents: string): void {
+    const fullPath = join(repoDir, path);
+    mkdirSync(dirname(fullPath), { recursive: true });
+    writeFileSync(fullPath, contents);
+  }
+
+  function readRepoFile(path: string): string {
+    return readFileSync(join(repoDir, path), "utf8");
+  }
+
+  function existsRepoFile(path: string): boolean {
+    return existsSync(join(repoDir, path));
+  }
+
+  function countClaudePrExcludeEntries(): number {
+    return readFileSync(getExcludePath(), "utf8")
+      .split(/\r?\n/)
+      .filter((line) => line === CLAUDE_PR_EXCLUDE_PATTERN).length;
+  }
+
+  function getExcludePath(): string {
+    const gitPath = git(["rev-parse", "--git-path", "info/exclude"]).trim();
+    return isAbsolute(gitPath) ? gitPath : join(repoDir, gitPath);
+  }
+});