fix: tty support

.changeset/late-sides-wonder.md

@@ -0,0 +1,5 @@
+---
+'dotenv-diff': patch
+---
+
+fixed interactive prompt may run in non-TTY environments

packages/cli/src/commands/prompts/prompts.ts

@@ -17,6 +17,13 @@ export async function confirmYesNo(
 ): Promise<boolean> {
   if (isYesMode) return true;
   if (isCiMode) return false;
+
+  // Avoid hanging in non-interactive environments (e.g. hooks/scripts without TTY)
+  const hasInteractiveTty = Boolean(
+    process.stdin?.isTTY && process.stdout?.isTTY,
+  );
+  if (!hasInteractiveTty) return false;
+
   const res = await prompts({
     type: 'select',
     name: 'ok',

packages/cli/test/e2e/cli.compare.e2e.test.ts

@@ -56,7 +56,7 @@ describe('added .env to gitignore with --compare and --fix', () => {
     fs.mkdirSync(path.join(cwd, 'src'), { recursive: true });
     fs.writeFileSync(
       path.join(cwd, 'src', 'index.ts'),
-      `const apiKey = process.env.API_KEY;`.trimStart(),
+      'const apiKey = process.env.API_KEY;'.trimStart(),
     );
 
     const res = runCli(cwd, ['--compare', '--fix']);
@@ -78,7 +78,7 @@ describe('added .env to gitignore with --compare and --fix', () => {
     fs.mkdirSync(path.join(cwd, 'src'), { recursive: true });
     fs.writeFileSync(
       path.join(cwd, 'src', 'index.ts'),
-      `const apiKey = process.env.API_KEY;`.trimStart(),
+      'const apiKey = process.env.API_KEY;'.trimStart(),
     );
 
     const res = runCli(cwd, ['--compare', '--json']);
@@ -89,17 +89,15 @@ describe('added .env to gitignore with --compare and --fix', () => {
     expect(json[0].gitignoreIssue?.reason).toBe('not-ignored');
   });
 
-  it('Will prompt .env.example file not found. and prompt if .env.local exists and .env.example is set to --example', async () => {
+  it('Will skip interactive prompt in non-TTY when .env.example is missing and --example is set', async () => {
     const cwd = tmpDir();
     fs.writeFileSync(path.join(cwd, '.env.local'), 'FOO=bar');
 
     const res = runCli(cwd, ['--compare', '--example', '.env.example']);
 
     expect(res.status).toBe(0);
     expect(res.stdout).toContain('▸ File not found');
-    expect(res.stdout).toContain(
-      'Do you want to create a .env.example file from .env.local?',
-    );
+    expect(res.stdout).toContain('▸ Skipping .env.example creation');
   });
 
   describe('Values mismatch checks', () => {

packages/cli/test/unit/commands/prompts/prompts.test.ts

@@ -6,6 +6,17 @@ vi.mock('prompts');
 
 const mockPrompts = prompts as unknown as ReturnType<typeof vi.fn>;
 
+function setTTY(stdinTTY: boolean, stdoutTTY: boolean): void {
+  Object.defineProperty(process.stdin, 'isTTY', {
+    value: stdinTTY,
+    configurable: true,
+  });
+  Object.defineProperty(process.stdout, 'isTTY', {
+    value: stdoutTTY,
+    configurable: true,
+  });
+}
+
 describe('confirmYesNo', () => {
   beforeEach(() => {
     vi.clearAllMocks();
@@ -32,6 +43,7 @@ describe('confirmYesNo', () => {
   });
 
   it('returns true when user selects Yes', async () => {
+    setTTY(true, true);
     mockPrompts.mockResolvedValue({ ok: true });
 
     const result = await confirmYesNo('Are you sure?', {
@@ -44,6 +56,7 @@ describe('confirmYesNo', () => {
   });
 
   it('returns false when user selects No', async () => {
+    setTTY(true, true);
     mockPrompts.mockResolvedValue({ ok: false });
 
     const result = await confirmYesNo('Are you sure?', {
@@ -56,6 +69,7 @@ describe('confirmYesNo', () => {
   });
 
   it('returns false when prompt returns undefined', async () => {
+    setTTY(true, true);
     mockPrompts.mockResolvedValue({});
 
     const result = await confirmYesNo('Are you sure?', {
@@ -65,4 +79,16 @@ describe('confirmYesNo', () => {
 
     expect(result).toBe(false);
   });
+
+  it('returns false when no TTY is available and does not prompt', async () => {
+    setTTY(false, false);
+
+    const result = await confirmYesNo('Are you sure?', {
+      isCiMode: false,
+      isYesMode: false,
+    });
+
+    expect(result).toBe(false);
+    expect(mockPrompts).not.toHaveBeenCalled();
+  });
 });