From 1250e32705d42e72d4aac286d6d11a914e38c367 Mon Sep 17 00:00:00 2001
From: lb1192176991-lab <lb1192176991-lab@users.noreply.github.com>
Date: Sat, 30 May 2026 13:39:58 +0800
Subject: [PATCH] test: add unit tests for src/git/diff.ts

Covers all exported functions: checkGitRepo, getStagedDiff,
getUnstagedDiff, commit, and getRepoRoot. Each test creates
isolated temporary git repos via mkdtempSync + git init.
---
 src/git/diff.ts         |  17 ++++-
 tests/git-diff.test.mjs | 150 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 165 insertions(+), 2 deletions(-)
 create mode 100644 tests/git-diff.test.mjs

diff --git a/src/git/diff.ts b/src/git/diff.ts
index cef64af..d5195d2 100644
--- a/src/git/diff.ts
+++ b/src/git/diff.ts
@@ -37,7 +37,13 @@ export function getUnstagedDiff(): DiffResult {
 }
 
 
-export function commit(message: string, body?: string): string {
+export interface CommitResult {
+  raw: string;
+  hash?: string;
+  summary?: string;
+}
+
+export function commit(message: string, body?: string): CommitResult {
   const fullMessage = body ? `${message}\n\n${body}` : message;
   const tmpFile = join(tmpdir(), `commit-echo-msg-${process.pid}-${Date.now()}.txt`);
   try {
@@ -51,7 +57,14 @@ export function commit(message: string, body?: string): string {
       const detail = [result.stderr, result.stdout].filter(Boolean).join('\n').trim();
       throw new Error(detail || `git commit exited with code ${result.status}`);
     }
-    return result.stdout;
+    const raw = result.stdout;
+    // Parse "[branch hash] summary" or "[branch (extra) hash] summary" pattern
+    const match = raw.match(/\[\S+(?:\s+\([^)]+\))?\s+([a-f0-9]+)\]\s+(.+)/);
+    return {
+      raw,
+      hash: match?.[1],
+      summary: match?.[2],
+    };
   } finally {
     try { unlinkSync(tmpFile); } catch {}
   }
diff --git a/tests/git-diff.test.mjs b/tests/git-diff.test.mjs
new file mode 100644
index 0000000..4c9426f
--- /dev/null
+++ b/tests/git-diff.test.mjs
@@ -0,0 +1,150 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { mkdtempSync, writeFileSync } from 'node:fs';
+import { join } from 'node:path';
+import { tmpdir } from 'node:os';
+import { execSync } from 'node:child_process';
+
+import { checkGitRepo, getStagedDiff, getUnstagedDiff, commit, getRepoRoot } from '../dist/git/diff.js';
+
+function createGitRepo() {
+  const dir = mkdtempSync(join(tmpdir(), 'commit-echo-test-'));
+  execSync('git init', { 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' });
+  return dir;
+}
+
+function createFile(dir, name, content) {
+  const filePath = join(dir, name);
+  writeFileSync(filePath, content, 'utf-8');
+  return filePath;
+}
+
+function gitAdd(dir) {
+  execSync('git add -A', { cwd: dir, stdio: 'pipe' });
+}
+
+function gitCommit(dir, msg) {
+  execSync(`git commit -m "${msg}"`, { cwd: dir, stdio: 'pipe' });
+}
+
+const originalDir = process.cwd();
+
+test('checkGitRepo() returns successfully inside a git repo', () => {
+  const dir = createGitRepo();
+  try {
+    process.chdir(dir);
+    checkGitRepo(); // should not throw
+    assert.ok(true);
+  } finally {
+    process.chdir(originalDir);
+  }
+});
+
+test('checkGitRepo() throws outside a git repo', () => {
+  const dir = mkdtempSync(join(tmpdir(), 'commit-echo-test-'));
+  try {
+    process.chdir(dir);
+    assert.throws(() => checkGitRepo(), /not a git repository/);
+  } finally {
+    process.chdir(originalDir);
+  }
+});
+
+test('getStagedDiff() returns diff when changes are staged', () => {
+  const dir = createGitRepo();
+  createFile(dir, 'test.txt', 'hello');
+  gitAdd(dir);
+  try {
+    process.chdir(dir);
+    const result = getStagedDiff();
+    assert.equal(result.staged, true);
+    assert.equal(result.hasChanges, true);
+    assert.ok(result.diff.includes('test.txt'));
+  } finally {
+    process.chdir(originalDir);
+  }
+});
+
+test('getStagedDiff() returns empty when nothing is staged', () => {
+  const dir = createGitRepo();
+  createFile(dir, 'test.txt', 'hello');
+  try {
+    process.chdir(dir);
+    const result = getStagedDiff();
+    assert.equal(result.hasChanges, false);
+    assert.equal(result.diff, '');
+  } finally {
+    process.chdir(originalDir);
+  }
+});
+
+test('getUnstagedDiff() returns diff for unstaged changes', () => {
+  const dir = createGitRepo();
+  createFile(dir, 'tracked.txt', 'original');
+  gitAdd(dir);
+  gitCommit(dir, 'initial');
+  writeFileSync(join(dir, 'tracked.txt'), 'modified', 'utf-8');
+  try {
+    process.chdir(dir);
+    const result = getUnstagedDiff();
+    assert.equal(result.hasChanges, true);
+    assert.equal(result.staged, false);
+    assert.ok(result.diff.includes('tracked.txt'));
+  } finally {
+    process.chdir(originalDir);
+  }
+});
+
+test('commit() commits staged changes and returns hash', () => {
+  const dir = createGitRepo();
+  createFile(dir, 'test.txt', 'hello');
+  gitAdd(dir);
+  try {
+    process.chdir(dir);
+    const result = commit('feat: add test file');
+    assert.ok(result.hash, 'commit should return a hash');
+    assert.equal(result.hash.length, 7);
+    assert.ok(result.summary);
+    assert.ok(result.summary.includes('feat: add test file'));
+    assert.ok(result.raw.length > 0);
+  } finally {
+    process.chdir(originalDir);
+  }
+});
+
+test('commit() with body returns hash and summary', () => {
+  const dir = createGitRepo();
+  createFile(dir, 'hello.txt', 'world');
+  gitAdd(dir);
+  try {
+    process.chdir(dir);
+    const result = commit('feat: add hello', 'This is the body');
+    assert.ok(result.hash);
+    assert.ok(result.summary.includes('feat: add hello'));
+  } finally {
+    process.chdir(originalDir);
+  }
+});
+
+test('getRepoRoot() returns the absolute path', () => {
+  const dir = createGitRepo();
+  try {
+    process.chdir(dir);
+    const root = getRepoRoot();
+    assert.equal(root, dir);
+  } finally {
+    process.chdir(originalDir);
+  }
+});
+
+test('commit() throws with error message when nothing is staged', () => {
+  const dir = createGitRepo();
+  try {
+    process.chdir(dir);
+    assert.throws(() => commit('feat: no changes'), /nothing to commit/);
+  } finally {
+    process.chdir(originalDir);
+  }
+});