diff --git a/tests/index.test.js b/tests/index.test.js
index 74cc983..8d2e3c7 100644
--- a/tests/index.test.js
+++ b/tests/index.test.js
@@ -11,14 +11,21 @@ import * as gitGptCommit from '../index.js'
 
 describe('Git GPT Commit', () => {
   let tempDir
+  let originalDir
 
   beforeEach(() => {
+    // Store original directory
+    originalDir = process.cwd()
+
     // Set up a new test environment before each test
     tempDir = setupTestRepo()
     vi.clearAllMocks()
   })
 
   afterEach(() => {
+    // Change back to original directory before cleaning up
+    process.chdir(originalDir)
+
     // Clean up the test environment after each test
     cleanupTestRepo(tempDir)
     vi.clearAllMocks()
diff --git a/tests/setup-mocks.js b/tests/setup-mocks.js
index 4c99e69..1dc7f2f 100644
--- a/tests/setup-mocks.js
+++ b/tests/setup-mocks.js
@@ -21,12 +21,12 @@ vi.mock('openai', () => {
   }
 })
 
-// index.jsモジュール全体をモック
+// Mock the entire index.js module
 vi.mock('../index.js', () => {
   return {
     getGitSummary: vi.fn((options) => {
       try {
-        // 実際のdiffコマンドを実行せず、ファイルの変更があるかチェック
+        // Check if there are file changes without actually executing the diff command
         const gitStatus = require('child_process')
           .execSync('git status --porcelain')
           .toString()
@@ -35,8 +35,8 @@ vi.mock('../index.js', () => {
           throw new Error('No changes to commit')
         }
 
-        // モックされたdiffの内容を返す
-        return `diff --git a/file1.js b/file1.js\nindex 123456..789012 100644\n--- a/file1.js\n+++ b/file1.js\n@@ -1,5 +1,8 @@\nfunction greet(name) {\n-  return \`Hello, \${name}!\`;\n+  // 名前が空の場合のデフォルト値を追加\n+  const userName = name || 'Guest';\n+  return \`Hello, \${userName}!\`;\n }`
+        // Return mocked diff content
+        return `diff --git a/file1.js b/file1.js\nindex 123456..789012 100644\n--- a/file1.js\n+++ b/file1.js\n@@ -1,5 +1,8 @@\nfunction greet(name) {\n-  return \`Hello, \${name}!\`;\n+  // Add default value when name is empty\n+  const userName = name || 'Guest';\n+  return \`Hello, \${userName}!\`;\n }`
       } catch (error) {
         throw new Error('Failed to get git summary')
       }
@@ -45,40 +45,40 @@ vi.mock('../index.js', () => {
       return 'Mock commit message'
     }),
     gitExtension: vi.fn(),
-    // その他必要な関数やオブジェクト
+    // Other necessary functions or objects
   }
 })
 
-// fs モジュールをモック
+// Mock fs module
 vi.mock('fs', async () => {
   const actual = await vi.importActual('fs')
 
   return {
     ...actual,
     existsSync: vi.fn((path) => {
-      // 特定のパスのみモックレスポンスを返す
+      // Return mock response only for specific paths
       if (path.includes('.git-gpt-commit-config.json')) {
         return true
       }
-      // それ以外は実際の実装を使用
+      // Use actual implementation for others
       return actual.existsSync(path)
     }),
     readFileSync: vi.fn((path, options) => {
-      // コンフィグファイルの場合、モックデータを返す
+      // Return mock data for config file
       if (path.includes('.git-gpt-commit-config.json')) {
         return JSON.stringify({
           model: 'gpt-4o',
           language: 'English',
         })
       }
-      // それ以外は実際の実装を使用
+      // Use actual implementation for others
       return actual.readFileSync(path, options)
     }),
     writeFileSync: vi.fn(),
   }
 })
 
-// commanderをモック
+// Mock commander
 vi.mock('commander', () => {
   const mockProgram = {
     command: vi.fn().mockReturnThis(),
@@ -95,7 +95,7 @@ vi.mock('commander', () => {
   }
 })
 
-// child_processをモック
+// Mock child_process
 vi.mock('child_process', async () => {
   const actual = await vi.importActual('child_process')
 
@@ -103,24 +103,24 @@ vi.mock('child_process', async () => {
     ...actual,
     execSync: vi.fn((command) => {
       if (typeof command === 'string') {
-        // git statusコマンドの場合は変更があるとみなす
+        // Treat as having changes for git status commands
         if (command.includes('git status')) {
           return Buffer.from('M file1.js')
         }
 
-        // git commitコマンドの場合はモック応答
+        // Mock response for git commit commands
         if (command.includes('git commit')) {
           return Buffer.from('Commit successful')
         }
       }
 
-      // その他のコマンドは実際に実行
+      // Actually execute other commands
       return actual.execSync(command)
     }),
     exec: vi.fn((command, callback) => {
       if (command.includes('git diff')) {
         const stdout =
-          "diff --git a/file1.js b/file1.js\nindex 123456..789012 100644\n--- a/file1.js\n+++ b/file1.js\n@@ -1,5 +1,8 @@\nfunction greet(name) {\n-  return `Hello, ${name}!`;\n+  // 名前が空の場合のデフォルト値を追加\n+  const userName = name || 'Guest';\n+  return `Hello, ${userName}!`;\n }"
+          "diff --git a/file1.js b/file1.js\nindex 123456..789012 100644\n--- a/file1.js\n+++ b/file1.js\n@@ -1,5 +1,8 @@\nfunction greet(name) {\n-  return \`Hello, \${name}!\`;\n+  // Add default value when name is empty\n+  const userName = name || 'Guest';\n+  return \`Hello, \${userName}!\`;\n }"
         callback(null, { stdout })
       } else {
         callback(null, { stdout: '' })
@@ -129,12 +129,12 @@ vi.mock('child_process', async () => {
   }
 })
 
-// promptsモジュールをモック
+// Mock prompts module
 vi.mock('prompts', () => ({
   default: vi.fn().mockResolvedValue({ value: true }),
 }))
 
-// process.exitをモック
+// Mock process.exit
 vi.stubGlobal('process', {
   ...process,
   exit: vi.fn((code) => {
diff --git a/tests/setup.js b/tests/setup.js
index ee1f000..1aaa754 100644
--- a/tests/setup.js
+++ b/tests/setup.js
@@ -17,10 +17,51 @@ if (fs.existsSync(testEnvPath)) {
  * @returns {string} Path to the created temporary directory
  */
 export function setupTestRepo() {
+  // Find the project root to access fixtures
+  let projectRoot = process.cwd()
+  let currentPath = projectRoot
+  while (!fs.existsSync(path.join(currentPath, 'package.json'))) {
+    const parentPath = path.dirname(currentPath)
+    if (parentPath === currentPath) break
+    currentPath = parentPath
+  }
+  if (fs.existsSync(path.join(currentPath, 'package.json'))) {
+    projectRoot = currentPath
+  }
+
   // Create a temporary directory
   const tempDir = path.join(os.tmpdir(), `git-gpt-commit-test-${Date.now()}`)
   fs.mkdirSync(tempDir, { recursive: true })
 
+  // Create fixtures directory in the temp directory
+  const fixturesDir = path.join(tempDir, 'fixtures')
+  fs.mkdirSync(fixturesDir, { recursive: true })
+
+  // Copy fixture files from original project to test directory
+  const sourceFixturesDir = path.join(projectRoot, 'fixtures')
+  if (fs.existsSync(sourceFixturesDir)) {
+    const files = fs.readdirSync(sourceFixturesDir)
+    files.forEach((file) => {
+      const sourcePath = path.join(sourceFixturesDir, file)
+      const destPath = path.join(fixturesDir, file)
+
+      if (fs.statSync(sourcePath).isFile()) {
+        fs.copyFileSync(sourcePath, destPath)
+      } else if (fs.statSync(sourcePath).isDirectory()) {
+        // Handle subdirectories like 'expected'
+        fs.mkdirSync(destPath, { recursive: true })
+        const subFiles = fs.readdirSync(sourcePath)
+        subFiles.forEach((subFile) => {
+          const subSourcePath = path.join(sourcePath, subFile)
+          const subDestPath = path.join(destPath, subFile)
+          if (fs.statSync(subSourcePath).isFile()) {
+            fs.copyFileSync(subSourcePath, subDestPath)
+          }
+        })
+      }
+    })
+  }
+
   // Initialize Git repository
   process.chdir(tempDir)
   execSync('git init')
@@ -40,7 +81,17 @@ export function setupTestRepo() {
  * @returns {string} Path to the copied file
  */
 export function copyFixture(fixtureName, destName = fixtureName) {
-  // Find the project root by looking for package.json up the directory tree
+  // First check if fixture exists in the current working directory
+  const localFixturePath = path.join(process.cwd(), 'fixtures', fixtureName)
+  const destPath = path.join(process.cwd(), destName)
+
+  // If fixture exists locally, use it
+  if (fs.existsSync(localFixturePath)) {
+    fs.copyFileSync(localFixturePath, destPath)
+    return destPath
+  }
+
+  // Otherwise, look for it in the project root
   let projectRoot = process.cwd()
   let currentPath = projectRoot
 
@@ -59,7 +110,6 @@ export function copyFixture(fixtureName, destName = fixtureName) {
   }
 
   const fixturePath = path.join(projectRoot, 'fixtures', fixtureName)
-  const destPath = path.join(process.cwd(), destName)
 
   if (!fs.existsSync(fixturePath)) {
     // Create a mock file if the fixture directory doesn't exist
@@ -94,6 +144,5 @@ export function modifyAndStageFile(filePath, content) {
  */
 export function cleanupTestRepo(tempDir) {
   // Delete the directory after the test
-  // テスト後にディレクトリを削除
   fs.rmSync(tempDir, { recursive: true, force: true })
 }