fix(@clack/prompts): collapse carriage returns in line-based taskLog output

Author: colinaaa

packages/prompts/src/task-log.ts

@@ -59,6 +59,13 @@ const appendRawMessage = (input: string, msg: string, prependNewline: boolean):
 	return next;
 };
 
+const collapseCarriageReturnUpdates = (input: string): string => {
+	return input
+		.split('\n')
+		.map((line) => line.slice(line.lastIndexOf('\r') + 1))
+		.join('\n');
+};
+
 /**
  * Renders a log which clears on success and remains on failure
  */
@@ -170,7 +177,7 @@ export const taskLog = (opts: TaskLogOptions) => {
 			if (buffer.value !== '') {
 				buffer.value += '\n';
 			}
-			buffer.value += sanitized;
+			buffer.value += collapseCarriageReturnUpdates(sanitized);
 			lastMessageWasRaw = false;
 		}
 		if (opts.limit !== undefined) {

packages/prompts/test/task-log.test.ts

@@ -134,6 +134,23 @@ describe.each(['true', 'false'])('taskLog (isCI = %s)', (isCI) => {
 			expect(output.buffer).toMatchSnapshot();
 		});
 
+		test('raw = false keeps only the last carriage return update when success shows the log', async () => {
+			const log = prompts.taskLog({
+				input,
+				output,
+				title: 'foo',
+			});
+
+			log.message('◒  Cloning repository\r◐  Cloning repository\r◓  Cloning repository\r◇  Repository cloned');
+			log.success('done!', { showLog: true });
+
+			const renderedLog = output.buffer.at(-1);
+			expect(renderedLog).toContain('◇  Repository cloned');
+			expect(renderedLog).not.toContain('◒  Cloning repository');
+			expect(renderedLog).not.toContain('◐  Cloning repository');
+			expect(renderedLog).not.toContain('◓  Cloning repository');
+		});
+
 		test('prints empty lines', async () => {
 			const log = prompts.taskLog({
 				input,
@@ -225,6 +242,24 @@ describe.each(['true', 'false'])('taskLog (isCI = %s)', (isCI) => {
 
 			expect(output.buffer).toMatchSnapshot();
 		});
+
+		test('raw = false keeps only the last carriage return update on error', () => {
+			const log = prompts.taskLog({
+				input,
+				output,
+				title: 'foo',
+			});
+
+			log.message('◒  Cloning repository\r◐  Cloning repository\r◓  Cloning repository\r◇  Repository cloned');
+
+			log.error('some error!');
+
+			const renderedLog = output.buffer.at(-1);
+			expect(renderedLog).toContain('◇  Repository cloned');
+			expect(renderedLog).not.toContain('◒  Cloning repository');
+			expect(renderedLog).not.toContain('◐  Cloning repository');
+			expect(renderedLog).not.toContain('◓  Cloning repository');
+		});
 	});
 
 	describe('success', () => {