From 592965a2953b4ddf0f2a63639d5bf1eaa9588c04 Mon Sep 17 00:00:00 2001
From: Hiroki Osame <hiroki.osame@gmail.com>
Date: Thu, 31 Aug 2023 13:11:01 +0900
Subject: [PATCH] fix(watch): wait for the process to exit

---
 src/watch/index.ts   |  7 ++++++-
 tests/specs/watch.ts | 44 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/src/watch/index.ts b/src/watch/index.ts
index b1379686..5b3c68d9 100644
--- a/src/watch/index.ts
+++ b/src/watch/index.ts
@@ -64,12 +64,17 @@ export const watchCommand = command({
 
 	let runProcess: ChildProcess | undefined;
 
-	const reRun = debounce(() => {
+	const reRun = debounce(async () => {
 		if (
 			runProcess
 			&& (!runProcess.killed && runProcess.exitCode === null)
 		) {
+			const waitForExit = new Promise((resolve) => {
+				runProcess!.on('exit', resolve);
+			});
 			runProcess.kill();
+
+			await waitForExit;
 		}
 
 		// Not first run
diff --git a/tests/specs/watch.ts b/tests/specs/watch.ts
index e216aede..01c0c487 100644
--- a/tests/specs/watch.ts
+++ b/tests/specs/watch.ts
@@ -106,6 +106,50 @@ export default testSuite(async ({ describe }, fixturePath: string) => {
 			await tsxProcess;
 		}, 10_000);
 
+		test('wait for exit', async ({ onTestFinish }) => {
+			const fixture = await createFixture({
+				'index.js': `
+				console.log('start');
+				const sleepSync = (delay) => {
+					const waitTo = Date.now() + delay;
+					while (Date.now() < waitTo) {}
+				};
+				process.on('exit', () => {
+					sleepSync(300);
+					console.log('end');
+				});
+				`,
+			});
+
+			onTestFinish(async () => await fixture.rm());
+
+			const tsxProcess = tsx({
+				args: [
+					'watch',
+					path.join(fixture.path, 'index.js'),
+				],
+			});
+
+			const stdout = await new Promise<string>((resolve) => {
+				const buffers: Buffer[] = [];
+				async function onStdOut(data: Buffer) {
+					buffers.push(data);
+					const chunkString = data.toString();
+					if (chunkString.match('start\n')) {
+						tsxProcess.stdin?.write('enter');
+					} else if (chunkString.match('end\n')) {
+						tsxProcess.kill();
+						resolve(Buffer.concat(buffers).toString());
+					}
+				}
+
+				tsxProcess.stdout!.on('data', onStdOut);
+				tsxProcess.stderr!.on('data', onStdOut);
+			});
+
+			expect(stdout).toBe('\u001Bcstart\nend\n');
+		}, 10_000);
+
 		describe('help', ({ test }) => {
 			test('shows help', async () => {
 				const tsxProcess = await tsx({