'use strict';
/**
 * #1146: git.base-branch resolver — single source of truth for default-branch detection.
 *
 * Tests:
 *   A. Config override wins (git.base_branch set → returned as-is, no git calls needed)
 *   B. origin/HEAD symref resolves → used
 *   C. origin/HEAD unset but git remote show origin knows HEAD → AUTHORITATIVE fallback
 *      (key regression: master repo with no origin/HEAD → must return "master", NOT "main")
 *   D. No origin/HEAD, no remote show, local branch "master" present → returns "master"
 *   E. No origin/HEAD, no remote show, local branch "main" present → returns "main"
 *   F. No origin/HEAD, no remote show, no local branches → returns "main" (last resort)
 *   G. Anti-regression guard: five affected workflows must NOT contain the
 *      duplicated bare `:-main` / `:-master` fallback pattern that was the root cause.
 *      They must call `gsd_run query git.base-branch` instead.
 *      (allow-test-rule: runtime-contract-is-the-product — the workflow .md content IS
 *       the runtime surface; the absence of the bad pattern is what ships to agents.)
 */

// allow-test-rule: runtime-contract-is-the-product
// Justification: the workflow .md files ARE the product surface — agents read and
// execute them directly. Guard G asserts that the resolved command appears in all five
// workflows, which requires reading those workflow files. Per TESTING-STANDARDS.md §6.

const { describe, test } = require('node:test');
const assert = require('node:assert/strict');
const fs = require('node:fs');
const os = require('node:os');
const path = require('node:path');
const { execSync } = require('node:child_process');

const { runGsdTools, cleanup } = require('./helpers.cjs');

// ─── helpers ──────────────────────────────────────────────────────────────────

/**
 * Create a minimal git repo in a temp dir, optionally setting up a remote
 * and local branches.
 */
function createGitRepo(opts = {}) {
  const { prefix = 'gsd-1146-', defaultBranch = 'master' } = opts;
  const dir = fs.mkdtempSync(path.join(os.tmpdir(), prefix));
  execSync(`git init -b ${defaultBranch}`, { cwd: dir, stdio: 'pipe' });
  execSync('git config user.email "test@test.com"', { cwd: dir, stdio: 'pipe' });
  execSync('git config user.name "Test"', { cwd: dir, stdio: 'pipe' });
  execSync('git config commit.gpgsign false', { cwd: dir, stdio: 'pipe' });
  // Need at least one commit so branches exist
  fs.writeFileSync(path.join(dir, 'README.md'), '# test\n');
  execSync('git add README.md', { cwd: dir, stdio: 'pipe' });
  execSync('git commit -m "init"', { cwd: dir, stdio: 'pipe' });
  return dir;
}

/**
 * Create a .planning dir so gsd-tools resolveProjectRoot doesn't bail.
 */
function addPlanning(dir) {
  fs.mkdirSync(path.join(dir, '.planning', 'phases'), { recursive: true });
}

/**
 * Write a gsd config.json with git.base_branch set.
 */
function setGsdConfig(dir, key, value) {
  const cfgDir = path.join(dir, '.planning');
  fs.mkdirSync(cfgDir, { recursive: true });
  const cfgPath = path.join(cfgDir, 'config.json');
  let cfg = {};
  try { cfg = JSON.parse(fs.readFileSync(cfgPath, 'utf8')); } catch (_) { /* new file */ }
  // Set nested key (dot notation). Guard every segment against prototype
  // pollution with inline literal checks at each write site — mirrors the
  // production guard in src/config.cts. A Set/pre-loop guard is NOT recognised
  // by CodeQL's js/prototype-pollution-utility query (see PR #752 / alert #40).
  const parts = key.split('.');
  let obj = cfg;
  for (let i = 0; i < parts.length - 1; i++) {
    const k = parts[i];
    if (k === '__proto__' || k === 'prototype' || k === 'constructor') {
      throw new Error(`setGsdConfig: unsafe config key segment '${k}'`);
    }
    if (typeof obj[k] !== 'object' || obj[k] === null) obj[k] = {};
    obj = obj[k];
  }
  const lastKey = parts[parts.length - 1];
  if (lastKey === '__proto__' || lastKey === 'prototype' || lastKey === 'constructor') {
    throw new Error(`setGsdConfig: unsafe config key segment '${lastKey}'`);
  }
  obj[lastKey] = value;
  fs.writeFileSync(cfgPath, JSON.stringify(cfg, null, 2) + '\n');
}

// Paths to the five affected workflow files
const WORKFLOW_DIR = path.join(__dirname, '..', 'gsd-core', 'workflows');
const AFFECTED_WORKFLOWS = [
  path.join(WORKFLOW_DIR, 'execute-phase.md'),
  path.join(WORKFLOW_DIR, 'quick.md'),
  path.join(WORKFLOW_DIR, 'ship.md'),
  path.join(WORKFLOW_DIR, 'complete-milestone.md'),
  path.join(WORKFLOW_DIR, 'pr-branch.md'),
];

// ─── Test suite ───────────────────────────────────────────────────────────────

describe('#1146: git.base-branch resolver', () => {

  test('A. config override git.base_branch → returned immediately', (t) => {
    const dir = createGitRepo({ prefix: 'gsd-1146-a-', defaultBranch: 'master' });
    t.after(() => cleanup(dir));
    addPlanning(dir);
    setGsdConfig(dir, 'git.base_branch', 'develop');

    const result = runGsdTools(['query', 'git.base-branch'], dir);
    assert.ok(result.success, `git.base-branch with config override failed:\n${result.error}`);
    const branch = result.output.trim();
    assert.strictEqual(branch, 'develop',
      `Expected config override 'develop', got: '${branch}'`);
  });

  test('B. origin/HEAD symref resolves → returned', (t) => {
    // Create an "origin" bare repo with main branch
    const originDir = createGitRepo({ prefix: 'gsd-1146-b-origin-', defaultBranch: 'main' });
    const worktreeDir = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-1146-b-wt-'));
    t.after(() => { cleanup(originDir); cleanup(worktreeDir); });

    // Clone from origin — this sets origin/HEAD
    execSync(`git clone "${originDir}" "${worktreeDir}"`, { stdio: 'pipe' });
    execSync('git config user.email "test@test.com"', { cwd: worktreeDir, stdio: 'pipe' });
    execSync('git config user.name "Test"', { cwd: worktreeDir, stdio: 'pipe' });
    addPlanning(worktreeDir);

    // Verify origin/HEAD is set (it should be after clone)
    const symref = execSync('git symbolic-ref refs/remotes/origin/HEAD', { cwd: worktreeDir, encoding: 'utf8' }).trim();
    assert.ok(symref.includes('origin/main'), `Expected origin/HEAD→origin/main, got: ${symref}`);

    const result = runGsdTools(['query', 'git.base-branch'], worktreeDir);
    assert.ok(result.success, `git.base-branch symref test failed:\n${result.error}`);
    const branch = result.output.trim();
    assert.strictEqual(branch, 'main',
      `Expected 'main' from origin/HEAD, got: '${branch}'`);
  });

  test('C. KEY REGRESSION — master repo, origin/HEAD unset → returns "master" not "main"', (t) => {
    // This is the bug: git init + remote add without git remote set-head → no origin/HEAD
    // Current code falls back to :-main → wrong. Fixed code uses `git remote show origin`.
    const originDir = createGitRepo({ prefix: 'gsd-1146-c-origin-', defaultBranch: 'master' });
    const cloneDir = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-1146-c-clone-'));
    t.after(() => { cleanup(originDir); cleanup(cloneDir); });

    // Manually add remote WITHOUT cloning (so origin/HEAD is never set)
    execSync('git init', { cwd: cloneDir, stdio: 'pipe' });
    execSync('git config user.email "test@test.com"', { cwd: cloneDir, stdio: 'pipe' });
    execSync('git config user.name "Test"', { cwd: cloneDir, stdio: 'pipe' });
    execSync('git config commit.gpgsign false', { cwd: cloneDir, stdio: 'pipe' });
    execSync(`git remote add origin "${originDir}"`, { cwd: cloneDir, stdio: 'pipe' });
    execSync('git fetch origin', { cwd: cloneDir, stdio: 'pipe' });
    // Explicitly delete origin/HEAD in case git fetch auto-set it (newer git versions may do this)
    try {
      execSync('git remote set-head origin --delete', { cwd: cloneDir, stdio: 'pipe' });
    } catch (_) { /* ignore — may not exist */ }
    addPlanning(cloneDir);

    // Confirm origin/HEAD is unset
    let hasSymref = true;
    try {
      execSync('git symbolic-ref refs/remotes/origin/HEAD', { cwd: cloneDir, stdio: 'pipe' });
    } catch (_) {
      hasSymref = false;
    }
    assert.strictEqual(hasSymref, false, 'Test setup: origin/HEAD must be unset for this test case');

    const result = runGsdTools(['query', 'git.base-branch'], cloneDir);
    assert.ok(result.success, `git.base-branch regression test failed:\n${result.error}`);
    const branch = result.output.trim();
    assert.strictEqual(branch, 'master',
      `BUG REGRESSION: master repo with origin/HEAD unset must return 'master', got: '${branch}'`);
  });

  test('D. No remote, local branch "master" present, "main" absent → returns "master"', (t) => {
    const dir = createGitRepo({ prefix: 'gsd-1146-d-', defaultBranch: 'master' });
    t.after(() => cleanup(dir));
    addPlanning(dir);
    // No remote configured — falls through to local branch detection

    const result = runGsdTools(['query', 'git.base-branch'], dir);
    assert.ok(result.success, `git.base-branch local branch test failed:\n${result.error}`);
    const branch = result.output.trim();
    assert.strictEqual(branch, 'master',
      `Expected 'master' from local branch detection, got: '${branch}'`);
  });

  test('E. No remote, local branch "main" present → returns "main"', (t) => {
    const dir = createGitRepo({ prefix: 'gsd-1146-e-', defaultBranch: 'main' });
    t.after(() => cleanup(dir));
    addPlanning(dir);

    const result = runGsdTools(['query', 'git.base-branch'], dir);
    assert.ok(result.success, `git.base-branch main branch test failed:\n${result.error}`);
    const branch = result.output.trim();
    assert.strictEqual(branch, 'main',
      `Expected 'main' from local branch detection, got: '${branch}'`);
  });

  test('F. No remote, no main/master local branch → returns "main" (last resort default)', (t) => {
    const dir = createGitRepo({ prefix: 'gsd-1146-f-', defaultBranch: 'develop' });
    t.after(() => cleanup(dir));
    addPlanning(dir);
    // Branch named "develop" — neither main nor master

    const result = runGsdTools(['query', 'git.base-branch'], dir);
    assert.ok(result.success, `git.base-branch default fallback test failed:\n${result.error}`);
    const branch = result.output.trim();
    assert.strictEqual(branch, 'main',
      `Expected 'main' as last resort default, got: '${branch}'`);
  });

  test('A2. config override with flat base_branch key (legacy form) → returned immediately', (t) => {
    const dir = createGitRepo({ prefix: 'gsd-1146-a2-', defaultBranch: 'master' });
    t.after(() => cleanup(dir));
    addPlanning(dir);
    // Write flat base_branch directly to config root (legacy form, not nested under "git")
    const cfgPath = require('node:path').join(dir, '.planning', 'config.json');
    require('node:fs').writeFileSync(cfgPath, JSON.stringify({ base_branch: 'release' }, null, 2) + '\n');

    const result = runGsdTools(['query', 'git.base-branch'], dir);
    assert.ok(result.success, `git.base-branch with flat config key failed:\n${result.error}`);
    const branch = result.output.trim();
    assert.strictEqual(branch, 'release',
      `Expected flat config override 'release', got: '${branch}'`);
  });

  test('H. No remote, both "main" and "master" local branches exist → returns "main" (main wins tie-break)', (t) => {
    // Tier-4 tie-break: when both main and master exist locally and no remote info is available,
    // "main" wins (documented in tryLocalBranch JSDoc — modern default).
    const dir = createGitRepo({ prefix: 'gsd-1146-h-', defaultBranch: 'master' });
    t.after(() => cleanup(dir));
    addPlanning(dir);
    // Create a "main" branch alongside the existing "master"
    const { execSync: exec } = require('node:child_process');
    exec('git branch main', { cwd: dir, stdio: 'pipe' });
    // No remote configured — falls to tier-4 (local branch existence)

    const result = runGsdTools(['query', 'git.base-branch'], dir);
    assert.ok(result.success, `git.base-branch both-branches test failed:\n${result.error}`);
    const branch = result.output.trim();
    assert.strictEqual(branch, 'main',
      `Expected 'main' to win when both main and master exist locally, got: '${branch}'`);
  });

  test('G. Anti-regression: all five affected workflows use gsd_run query git.base-branch, not bare :-main / :-master', () => {
    // The root-cause pattern: DEFAULT_BRANCH=${DEFAULT_BRANCH:-main} or BASE_BRANCH="${BASE_BRANCH:-main}"
    // After fix: workflows call gsd_run query git.base-branch and remove the bare fallback.
    const BAD_PATTERN = /\$\{(?:DEFAULT_BRANCH|BASE_BRANCH):-(?:main|master)\}/;
    const RESOLVER_CALL = /gsd_run query git\.base-branch/;

    for (const wfPath of AFFECTED_WORKFLOWS) {
      const name = path.basename(wfPath);
      const content = fs.readFileSync(wfPath, 'utf8');

      assert.ok(
        !BAD_PATTERN.test(content),
        `${name} still contains the bare :-main/:-master fallback pattern. ` +
        'Must be replaced with gsd_run query git.base-branch (Issue #1146).',
      );

      assert.ok(
        RESOLVER_CALL.test(content),
        `${name} does not call \`gsd_run query git.base-branch\`. ` +
        'All five affected workflows must delegate to the single resolver (Issue #1146).',
      );
    }
  });
});

// ─── gitWorktreeInfoInternal: behaviour (#1268 T0, T1 #1277) ─────────────────

const gitBaseBranch = require(path.join(__dirname, '..', 'gsd-core', 'bin', 'lib', 'git-base-branch.cjs'));
const { createTempGitProject, createTempDir } = require('./helpers.cjs');

describe('#1268 gitWorktreeInfoInternal: relocation to git-base-branch', () => {
  test('gitWorktreeInfoInternal(createTempGitProject()) returns {inside:true, worktreeRoot:<non-empty string>}', (t) => {
    const dir = createTempGitProject('gsd-wt-info-');
    t.after(() => cleanup(dir));
    const result = gitBaseBranch.gitWorktreeInfoInternal(dir);
    assert.strictEqual(result.inside, true, 'inside must be true for a git project dir');
    assert.ok(typeof result.worktreeRoot === 'string' && result.worktreeRoot.length > 0,
      `worktreeRoot must be a non-empty string, got: ${JSON.stringify(result.worktreeRoot)}`);
  });

  test('gitWorktreeInfoInternal(createTempDir()) returns {inside:false, worktreeRoot:null} for a non-git dir', (t) => {
    const dir = createTempDir('gsd-wt-info-nongit-');
    t.after(() => cleanup(dir));
    const result = gitBaseBranch.gitWorktreeInfoInternal(dir);
    assert.strictEqual(result.inside, false, 'inside must be false for a non-git dir');
    assert.strictEqual(result.worktreeRoot, null, 'worktreeRoot must be null for a non-git dir');
  });

  test('gitWorktreeInfoInternal never throws (non-git dir)', (t) => {
    const dir = createTempDir('gsd-wt-info-nothrow-');
    t.after(() => cleanup(dir));
    assert.doesNotThrow(() => gitBaseBranch.gitWorktreeInfoInternal(dir));
  });
});

// ─── setGsdConfig prototype-pollution guard (#1406) ───────────────────────────

describe('#1406: setGsdConfig prototype-pollution guard', () => {
  test('rejects __proto__ as a key segment', (t) => {
    const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-1406-'));
    t.after(() => cleanup(dir));
    assert.throws(() => setGsdConfig(dir, '__proto__', 'x'), /unsafe config key segment/);
    assert.throws(() => setGsdConfig(dir, '__proto__.polluted', true), /unsafe config key segment/);
  });

  test('rejects constructor / prototype chain segments', (t) => {
    const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-1406-'));
    t.after(() => cleanup(dir));
    assert.throws(() => setGsdConfig(dir, 'constructor.prototype.polluted', true), /unsafe config key segment/);
    assert.throws(() => setGsdConfig(dir, 'safe.__proto__', true), /unsafe config key segment/);
    assert.throws(() => setGsdConfig(dir, 'a.prototype.b', true), /unsafe config key segment/);
  });

  test('does not pollute Object.prototype after rejected attempts', (t) => {
    const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-1406-'));
    t.after(() => cleanup(dir));
    try { setGsdConfig(dir, '__proto__.polluted', true); } catch (_) { /* expected */ }
    try { setGsdConfig(dir, 'constructor.prototype.polluted', true); } catch (_) { /* expected */ }
    try { setGsdConfig(dir, 'a.__proto__.polluted', true); } catch (_) { /* expected */ }
    assert.strictEqual(({}).polluted, undefined);
    assert.strictEqual(Object.prototype.polluted, undefined);
  });

  test('still writes a normal nested key', (t) => {
    const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-1406-'));
    t.after(() => cleanup(dir));
    setGsdConfig(dir, 'git.base_branch', 'develop');
    const cfgPath = path.join(dir, '.planning', 'config.json');
    const cfg = JSON.parse(fs.readFileSync(cfgPath, 'utf8'));
    assert.strictEqual(cfg.git.base_branch, 'develop');
  });
});


// ────────────────────────────────────────────────────────────────────────
// Folded from tests/bug-2004-pr-branch-milestone.test.cjs — consolidation epic #1969 (B4 #1973)
// ────────────────────────────────────────────────────────────────────────
{
  const { describe: __foldDescribe } = require('node:test');
  __foldDescribe("folded:bug-2004-pr-branch-milestone (consolidation epic #1969 B4 #1973)", () => {
/**
 * Regression tests for bug #2004
 *
 * /gsd-pr-branch must not exclude milestone archive and structural planning
 * commits. The previous implementation filtered ALL .planning/-only commits,
 * including STATE.md, ROADMAP.md, MILESTONES.md, and milestones/** updates
 * that are needed to preserve repository planning state after a merge.
 *
 * Fixed: pr-branch.md now distinguishes:
 *   - Transient planning commits (phase plans, summaries, research, context) → EXCLUDE
 *   - Structural planning commits (STATE.md, ROADMAP.md, MILESTONES.md,
 *     PROJECT.md, milestones/**) → INCLUDE
 *   - Code commits (any non-.planning/ file) → INCLUDE
 *   - Mixed commits (code + planning) → INCLUDE
 */

'use strict';

const { describe, test } = require('node:test');
const assert = require('node:assert/strict');
const fs = require('node:fs');
const path = require('node:path');

const workflowPath = path.resolve(
  __dirname, '..', 'gsd-core', 'workflows', 'pr-branch.md'
);

describe('bug #2004: pr-branch preserves structural planning commits', () => {
  let content;

  test('setup: pr-branch workflow is readable', () => {
    content = fs.readFileSync(workflowPath, 'utf-8');
    assert.ok(content.length > 0, 'pr-branch.md must not be empty');
  });

  test('workflow distinguishes structural vs transient planning commits', () => {
    content = content || fs.readFileSync(workflowPath, 'utf-8');
    // Must contain language distinguishing structural from transient/phase planning files
    assert.ok(
      /structural|milestone.*archive|STATE\.md.*INCLUDE|preserve.*milestone|milestone.*preserve/i.test(content),
      'pr-branch.md must distinguish structural planning commits from transient ones'
    );
  });

  test('workflow lists STATE.md and ROADMAP.md as structural files to preserve', () => {
    content = content || fs.readFileSync(workflowPath, 'utf-8');
    assert.ok(
      content.includes('STATE.md'),
      'pr-branch.md must reference STATE.md as a structural file to preserve'
    );
    assert.ok(
      content.includes('ROADMAP.md'),
      'pr-branch.md must reference ROADMAP.md as a structural file to preserve'
    );
  });

  test('workflow lists MILESTONES.md or milestones/ as structural files to preserve', () => {
    content = content || fs.readFileSync(workflowPath, 'utf-8');
    assert.ok(
      content.includes('MILESTONES.md') || content.includes('milestones/'),
      'pr-branch.md must reference MILESTONES.md or milestones/ as structural files to preserve'
    );
  });

  test('workflow has four commit categories (code, planning-only, mixed, structural)', () => {
    content = content || fs.readFileSync(workflowPath, 'utf-8');
    // Must have at least a "structural" or "milestone" category beyond the original three
    assert.ok(
      /structural.*commit|milestone.*commit|commit.*structural|commit.*milestone/i.test(content) ||
      /INCLUDE.*STATE\.md|STATE\.md.*INCLUDE/i.test(content),
      'pr-branch.md must classify structural planning commits as INCLUDE'
    );
  });

  test('create_pr_branch step does not rm -r --cached all of .planning/', () => {
    content = content || fs.readFileSync(workflowPath, 'utf-8');
    // The original bug: `git rm -r --cached .planning/` nuked structural files.
    // The fix must either remove this wholesale rm or scope it to transient dirs.
    // Acceptable: narrowed rm targeting only phase/, quick/, research/, etc.
    // Not acceptable: `git rm -r --cached .planning/` with no scoping.
    const hasUnscoped = /git rm -r --cached \.planning\/(?!\*)?(?!phases|quick|research|threads|todos|debug|seeds|ui-reviews|codebase)/
      .test(content);
    assert.ok(
      !hasUnscoped,
      'create_pr_branch must not use unscoped "git rm -r --cached .planning/" — scope to transient subdirectories only'
    );
  });
});
  });
}

// ────────────────────────────────────────────────────────────────────────
// Folded from tests/bug-2916-handle-branching-default-base.test.cjs — consolidation epic #1969 (B6 #1975)
// ────────────────────────────────────────────────────────────────────────
{
  const { describe: __foldDescribe } = require('node:test');
  __foldDescribe("folded:bug-2916-handle-branching-default-base (consolidation epic #1969 B6 #1975)", () => {
/**
 * Regression test for #2916: execute-phase `handle_branching` step creates the
 * per-phase branch off whatever HEAD is currently checked out (typically the
 * previous phase's unmerged branch) instead of off `origin/HEAD`.
 *
 * The bug compounded phases on top of each other and stranded them unpushed
 * for weeks. The fix:
 *   1. Detect the default branch via `git symbolic-ref refs/remotes/origin/HEAD`.
 *   2. If $BRANCH_NAME exists, switch to it (preserve existing behavior).
 *   3. Otherwise, ff-update the default branch from origin and create the new
 *      phase branch off the default-branch tip.
 *   4. Refuse-or-warn on dirty working tree.
 *   5. Post-creation, assert `git rev-list --count $DEFAULT_BRANCH..HEAD == 0`.
 *
 * This test extracts the bash payload from the <step name="handle_branching">
 * block in execute-phase.md (parsed structurally — no regex on prose), executes
 * it inside a fixture git repo where HEAD sits on a previous-phase branch with
 * extra commits, and asserts that the new phase branch's tip equals
 * `origin/main` (no commits inherited from the previous phase).
 */

const { describe, test } = require('node:test');
const assert = require('node:assert/strict');
const { execFileSync } = require('node:child_process');
const fs = require('node:fs');
const os = require('node:os');
const path = require('node:path');

const { cleanup } = require('./helpers.cjs');

const EXECUTE_PHASE_PATH = path.join(
  __dirname,
  '..',
  'gsd-core',
  'workflows',
  'execute-phase.md'
);

const GIT_ENV = Object.freeze({
  ...process.env,
  GIT_AUTHOR_NAME: 'Test',
  GIT_AUTHOR_EMAIL: 'test@test.com',
  GIT_COMMITTER_NAME: 'Test',
  GIT_COMMITTER_EMAIL: 'test@test.com',
});

function git(cwd, ...args) {
  return execFileSync('git', args, {
    cwd,
    env: GIT_ENV,
    stdio: ['pipe', 'pipe', 'pipe'],
  })
    .toString()
    .trim();
}

/**
 * Structurally extract the bash code that the handle_branching step instructs
 * the agent to run. We:
 *   1. Locate the <step name="handle_branching"> ... </step> block.
 *   2. Walk its body looking for fenced ```bash blocks.
 *   3. Concatenate every bash block in the step (the fix may use more than one).
 *
 * No `.includes()` content checks — we parse fence-delimited code blocks the
 * same way a markdown parser would.
 */
function extractHandleBranchingBash() {
  const content = fs.readFileSync(EXECUTE_PHASE_PATH, 'utf-8');
  const lines = content.split(/\r?\n/);

  let start = -1;
  let end = -1;
  for (let i = 0; i < lines.length; i += 1) {
    if (start === -1 && /^<step\s+name="handle_branching">\s*$/.test(lines[i])) {
      start = i + 1;
    } else if (start !== -1 && /^<\/step>\s*$/.test(lines[i])) {
      end = i;
      break;
    }
  }
  if (start === -1 || end === -1) {
    throw new Error(
      'execute-phase.md does not contain a <step name="handle_branching"> ... </step> block'
    );
  }

  const bashBlocks = [];
  let inBash = false;
  let buffer = [];
  for (let i = start; i < end; i += 1) {
    const line = lines[i];
    if (!inBash && /^```bash\s*$/.test(line)) {
      inBash = true;
      buffer = [];
      continue;
    }
    if (inBash && /^```\s*$/.test(line)) {
      bashBlocks.push(buffer.join('\n'));
      inBash = false;
      continue;
    }
    if (inBash) buffer.push(line);
  }
  if (bashBlocks.length === 0) {
    throw new Error(
      'handle_branching step contains no ```bash code blocks to execute'
    );
  }
  return bashBlocks.join('\n');
}

/**
 * Build a fixture: a bare "origin" repo with the named default branch (one
 * commit), a clone with `origin/HEAD` pointed at it, and a checked-out
 * previous-phase branch carrying its own unmerged commit.
 *
 * `defaultBranch` is parameterized so callers can lock in that the workflow
 * honors `git symbolic-ref refs/remotes/origin/HEAD` rather than silently
 * defaulting to `main` (#2921 CR feedback — quick-branching.test.cjs got the
 * same treatment in 80f14cac; this test deserves the same coverage).
 */
function setupFixture(defaultBranch = 'main') {
  const root = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-2916-'));
  const seedPath = path.join(root, 'seed');
  const originPath = path.join(root, 'origin.git');
  const clonePath = path.join(root, 'clone');

  fs.mkdirSync(seedPath);
  git(seedPath, 'init', '-b', defaultBranch);
  git(seedPath, 'config', 'commit.gpgsign', 'false');
  fs.writeFileSync(path.join(seedPath, 'README.md'), '# seed\n');
  git(seedPath, 'add', 'README.md');
  git(seedPath, 'commit', '-m', 'initial');

  git(root, 'clone', '--bare', seedPath, originPath);
  git(originPath, 'symbolic-ref', 'HEAD', `refs/heads/${defaultBranch}`);

  git(root, 'clone', originPath, clonePath);
  git(clonePath, 'config', 'commit.gpgsign', 'false');
  git(clonePath, 'config', 'user.email', 'test@test.com');
  git(clonePath, 'config', 'user.name', 'Test');

  // Simulate finishing a previous phase: branch off the default branch, add
  // a commit, and *stay* on it (the failure scenario described in the bug).
  git(clonePath, 'checkout', '-b', 'feature/phase-01-foundation');
  fs.writeFileSync(path.join(clonePath, 'phase01.txt'), 'phase 1 work\n');
  git(clonePath, 'add', 'phase01.txt');
  git(clonePath, 'commit', '-m', 'phase 01 work');

  return { root, clonePath, defaultBranch };
}

function runHandleBranchingStep(bash, cwd, branchName) {
  // Write the script to a sibling tempdir, not inside the repo — putting it in
  // `cwd` would create an untracked file that trips `git status --porcelain`
  // and steers the step into its dirty-tree fallback path.
  const scriptDir = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-2916-step-'));
  const scriptPath = path.join(scriptDir, 'handle-branching.sh');
  const script = `#!/usr/bin/env bash\nset -uo pipefail\nBRANCH_NAME="${branchName}"\n${bash}\n`;
  fs.writeFileSync(scriptPath, script, { mode: 0o755 });
  try {
    return execFileSync('bash', [scriptPath], {
      cwd,
      env: GIT_ENV,
      stdio: ['pipe', 'pipe', 'pipe'],
    }).toString();
  } finally {
    cleanup(scriptDir);
  }
}

describe('handle_branching branches off origin/HEAD, not current HEAD (#2916)', () => {
  // Run against `main` (conventional default) and `trunk` (non-main default
  // exercising the symbolic-ref code path) so a regression that hard-codes
  // `main` instead of consulting origin/HEAD will fail the trunk variant.
  for (const defaultBranch of ['main', 'trunk']) {
    test(`new phase branch branches off origin/${defaultBranch} with 0 inherited commits`, () => {
      const bash = extractHandleBranchingBash();
      const { root, clonePath } = setupFixture(defaultBranch);

      try {
        const upstream = `origin/${defaultBranch}`;

        assert.equal(
          git(clonePath, 'rev-parse', '--abbrev-ref', 'HEAD'),
          'feature/phase-01-foundation'
        );
        assert.equal(
          git(clonePath, 'rev-list', '--count', `${upstream}..HEAD`),
          '1',
          `fixture should be 1 commit ahead of ${upstream}`
        );

        runHandleBranchingStep(bash, clonePath, 'feature/phase-02-content-sync');

        assert.equal(
          git(clonePath, 'rev-parse', '--abbrev-ref', 'HEAD'),
          'feature/phase-02-content-sync',
          'handle_branching should switch to the new phase branch'
        );

        const inherited = git(clonePath, 'rev-list', '--count', `${upstream}..HEAD`);
        assert.equal(
          inherited,
          '0',
          `new phase branch must branch off ${upstream}, but inherited ${inherited} commit(s) from previous-phase HEAD`
        );
        assert.equal(
          git(clonePath, 'rev-parse', 'HEAD'),
          git(clonePath, 'rev-parse', upstream),
          `new phase branch tip must equal ${upstream} tip`
        );
      } finally {
        cleanup(root);
      }
    });
  }

  test('handle_branching reuses an existing branch instead of forking again', () => {
    const bash = extractHandleBranchingBash();
    const { root, clonePath } = setupFixture();

    try {
      // Pre-create the target branch off origin/main with its own commit, then
      // walk away to a different branch — the step must switch back to it.
      git(clonePath, 'checkout', '-B', 'feature/phase-02-content-sync', 'origin/main');
      fs.writeFileSync(path.join(clonePath, 'phase02.txt'), 'phase 2 work\n');
      git(clonePath, 'add', 'phase02.txt');
      git(clonePath, 'commit', '-m', 'phase 02 wip');
      const phase02Sha = git(clonePath, 'rev-parse', 'HEAD');
      git(clonePath, 'checkout', 'feature/phase-01-foundation');

      runHandleBranchingStep(bash, clonePath, 'feature/phase-02-content-sync');

      assert.equal(
        git(clonePath, 'rev-parse', '--abbrev-ref', 'HEAD'),
        'feature/phase-02-content-sync'
      );
      assert.equal(
        git(clonePath, 'rev-parse', 'HEAD'),
        phase02Sha,
        'existing-branch tip must be preserved (no rebase/reset)'
      );
    } finally {
      cleanup(root);
    }
  });
});
  });
}