[Bug] Prevent hard process exit on Ctrl+C if an onCancel callback is passed to spinner

.changeset/clever-rules-invent.md

@@ -0,0 +1,6 @@
+---
+"@clack/prompts": minor
+"@clack/core": minor
+---
+
+Fixed spinner onCancel not being called on Ctrl+C and prevents process.exit call

packages/core/src/utils/index.ts

@@ -29,13 +29,15 @@ interface BlockOptions {
 	output?: Writable;
 	overwrite?: boolean;
 	hideCursor?: boolean;
+	onSoftCancel?: () => void;
 }
 
 export function block({
 	input = stdin,
 	output = stdout,
 	overwrite = true,
 	hideCursor = true,
+	onSoftCancel,
 }: BlockOptions = {}) {
 	const rl = readline.createInterface({
 		input,
@@ -52,8 +54,12 @@ export function block({
 	const clear = (data: Buffer, { name, sequence }: Key) => {
 		const str = String(data);
 		if (isActionKey([str, name, sequence], 'cancel')) {
-			if (hideCursor) output.write(cursor.show);
-			process.exit(0);
+			if (typeof onSoftCancel === 'function') {
+				onSoftCancel();
+			} else {
+				if (hideCursor) output.write(cursor.show);
+				process.exit(0);
+			}
 			return;
 		}
 		if (!overwrite) return;
@@ -78,8 +84,10 @@ export function block({
 			input.setRawMode(false);
 		}
 
-		// @ts-expect-error fix for https://github.com/nodejs/node/issues/31762#issuecomment-1441223907
-		rl.terminal = false;
+		if (typeof onSoftCancel !== 'function') {
+			// @ts-expect-error fix for https://github.com/nodejs/node/issues/31762#issuecomment-1441223907
+			rl.terminal = false;
+		}
 		rl.close();
 	};
 }

packages/prompts/README.md

@@ -271,6 +271,27 @@ s.start('Installing via npm');
 s.stop('Installed via npm');
 ```
 
+Note: The `Ctrl+C` input will hard-stop the process with a `process.exit(0)` call.
+If you wish to avoid this behavior, pass an `onCancel` callback to the spinner initialization function.
+
+```js
+import { spinner, log } from '@clack/prompts';
+
+const s = spinner({
+  onCancel: () => {
+    // Do something...or nothing
+    log.warn('Coolness reached 3.14%');
+  }
+});
+
+s.start('Downloading coolness...');
+// Do stuff...then hit Ctrl+C to cancel
+s.stop('Maximum coolness reached! :)'); // Note: This does nothing if the spinner was cancelled
+
+// Carry on... (teardown connections, etc.)
+
+```
+
 ### Progress
 
 The progress component extends the spinner component to add a progress bar to visualize the progression of an action.

packages/prompts/src/spinner.ts

@@ -56,6 +56,7 @@ export const spinner = ({
 	let _origin: number = performance.now();
 	const columns = getColumns(output);
 	const styleFn = opts?.styleFrame ?? defaultStyleFn;
+	const isSoftCancel = typeof onCancel === 'function';
 
 	const handleExit = (code: number) => {
 		const msg =
@@ -131,7 +132,7 @@ export const spinner = ({
 
 	const start = (msg = ''): void => {
 		isSpinnerActive = true;
-		unblock = block({ output });
+		unblock = block({ output, onSoftCancel: isSoftCancel ? () => handleExit(1) : undefined });
 		_message = removeTrailingDots(msg);
 		_origin = performance.now();
 		if (hasGuide) {

packages/prompts/test/__snapshots__/spinner.test.ts.snap

@@ -11,6 +11,17 @@ exports[`spinner (isCI = false) > can be aborted by a signal 1`] = `
 ]
 `;
 
+exports[`spinner (isCI = false) > can be cancelled by Ctrl+C without exiting process 1`] = `
+[
+  "<cursor.hide>",
+  "│
+",
+  "■  Canceled
+",
+  "<cursor.show>",
+]
+`;
+
 exports[`spinner (isCI = false) > clear > stops and clears the spinner from the output 1`] = `
 [
   "<cursor.hide>",
@@ -324,6 +335,15 @@ exports[`spinner (isCI = false) > message > sets message for next frame 1`] = `
 ]
 `;
 
+exports[`spinner (isCI = false) > process exit handling > hard-exits the process on Ctrl+C when no onCancel callback is provided 1`] = `
+[
+  "<cursor.hide>",
+  "│
+",
+  "<cursor.show>",
+]
+`;
+
 exports[`spinner (isCI = false) > process exit handling > prioritizes cancel option over global setting 1`] = `
 [
   "<cursor.hide>",
@@ -606,6 +626,17 @@ exports[`spinner (isCI = true) > can be aborted by a signal 1`] = `
 ]
 `;
 
+exports[`spinner (isCI = true) > can be cancelled by Ctrl+C without exiting process 1`] = `
+[
+  "<cursor.hide>",
+  "│
+",
+  "■  Canceled
+",
+  "<cursor.show>",
+]
+`;
+
 exports[`spinner (isCI = true) > clear > stops and clears the spinner from the output 1`] = `
 [
   "<cursor.hide>",
@@ -719,6 +750,15 @@ exports[`spinner (isCI = true) > message > sets message for next frame 1`] = `
 ]
 `;
 
+exports[`spinner (isCI = true) > process exit handling > hard-exits the process on Ctrl+C when no onCancel callback is provided 1`] = `
+[
+  "<cursor.hide>",
+  "│
+",
+  "<cursor.show>",
+]
+`;
+
 exports[`spinner (isCI = true) > process exit handling > prioritizes cancel option over global setting 1`] = `
 [
   "<cursor.hide>",

packages/prompts/test/spinner.test.ts

@@ -411,6 +411,36 @@ describe.each(['true', 'false'])('spinner (isCI = %s)', (isCI) => {
 				prompts.settings.messages.cancel = originalCancelMessage;
 			}
 		});
+
+		test('hard-exits the process on Ctrl+C when no onCancel callback is provided', () => {
+			const exitSpy = vi.spyOn(process, 'exit').mockImplementation(((code?: number) => {
+				return code ?? 0;
+			}) as typeof process.exit);
+			const result = prompts.spinner({ output });
+
+			result.start('Testing');
+
+			// Simulate Ctrl+C keypress
+			const ctrlCEvent = Buffer.from([0x03]); // ASCII for Ctrl+C
+			process.stdin.emit('keypress', ctrlCEvent, { name: 'c', ctrl: true });
+
+			expect(output.buffer).toMatchSnapshot();
+			expect(exitSpy).toHaveBeenCalledWith(0);
+		});
+	});
+
+	test('can be cancelled by Ctrl+C without exiting process', () => {
+		const onCancel = vi.fn();
+		const result = prompts.spinner({ output, onCancel });
+
+		result.start('Testing');
+
+		// Simulate Ctrl+C keypress
+		const ctrlCEvent = Buffer.from([0x03]); // ASCII for Ctrl+C
+		process.stdin.emit('keypress', ctrlCEvent, { name: 'c', ctrl: true });
+
+		expect(onCancel).toHaveBeenCalled();
+		expect(output.buffer).toMatchSnapshot();
 	});
 
 	test('can be aborted by a signal', async () => {