fix(dev): wait until all app server descendants have been killed

packages/remix-dev/devServer_unstable/index.ts

@@ -22,6 +22,7 @@ import type { Result } from "../result";
 import { err, ok } from "../result";
 import invariant from "../invariant";
 import { logger } from "../tux";
+import { kill, killtree } from "./proc";
 
 type Origin = {
   scheme: string;
@@ -214,7 +215,9 @@ export let serve = async (
         try {
           let start = Date.now();
           if (state.appServer === undefined || options.restart) {
-            await kill(state.appServer);
+            if (state.appServer?.pid) {
+              await killtree(state.appServer.pid);
+            }
             state.appServer = startAppServer(options.command);
           }
           let appReady = await state.appReady!.result;
@@ -276,7 +279,7 @@ export let serve = async (
   server.listen(origin.port);
 
   return new Promise(() => {}).finally(async () => {
-    await kill(state.appServer);
+    state.appServer?.pid && (await kill(state.appServer.pid));
     websocket.close();
     server.close();
     await dispose();
@@ -290,25 +293,3 @@ let clean = (config: RemixConfig) => {
 };
 
 let relativePath = (file: string) => path.relative(process.cwd(), file);
-
-let kill = async (p?: execa.ExecaChildProcess) => {
-  if (p === undefined) return;
-  let channel = Channel.create<void>();
-  p.on("exit", channel.ok);
-
-  // https://github.com/nodejs/node/issues/12378
-  if (process.platform === "win32") {
-    try {
-      await execa("taskkill", ["/pid", String(p.pid), "/f", "/t"]);
-    } catch (error) {
-      // if exit code is 128, app server process is already dead
-      if (!(error instanceof Error)) throw error;
-      if (!("exitCode" in error)) throw error;
-      if (error.exitCode !== 128) throw error;
-    }
-  } else {
-    p.kill("SIGTERM", { forceKillAfterTimeout: 1_000 });
-  }
-
-  await channel.result;
-};

packages/remix-dev/devServer_unstable/proc.ts

@@ -0,0 +1,46 @@
+import execa from "execa";
+import pidtree from "pidtree";
+
+let isWindows = process.platform === "win32";
+
+export let kill = async (pid: number) => {
+  try {
+    let cmd = isWindows
+      ? ["taskkill", "/F", "/PID", pid.toString()]
+      : ["kill", "-9", pid.toString()];
+    await execa(cmd[0], cmd.slice(1));
+  } catch (error) {
+    throw new Error(`Failed to kill process ${pid}: ${error}`);
+  }
+};
+
+let isAlive = (pid: number) => {
+  try {
+    process.kill(pid, 0);
+    return true;
+  } catch (error) {
+    return false;
+  }
+};
+
+export let killtree = async (pid: number) => {
+  let descendants = await pidtree(pid);
+  let pids = [pid, ...descendants];
+  await kill(pid);
+  return new Promise<void>((resolve, reject) => {
+    let check = setInterval(() => {
+      let alive = pids.filter(isAlive);
+      if (alive.length === 0) {
+        clearInterval(check);
+        resolve();
+      }
+    }, 50);
+
+    setTimeout(() => {
+      clearInterval(check);
+      reject(
+        new Error("Timeout: Processes did not exit within the specified time.")
+      );
+    }, 2000);
+  });
+};

packages/remix-dev/package.json

@@ -54,6 +54,7 @@
     "ora": "^5.4.1",
     "picocolors": "^1.0.0",
     "picomatch": "^2.3.1",
+    "pidtree": "^0.6.0",
     "postcss": "^8.4.19",
     "postcss-discard-duplicates": "^5.1.0",
     "postcss-load-config": "^4.0.1",

yarn.lock

@@ -10947,6 +10947,11 @@ pidtree@^0.3.0:
   resolved "https://registry.npmjs.org/pidtree/-/pidtree-0.3.1.tgz"
   integrity sha512-qQbW94hLHEqCg7nhby4yRC7G2+jYHY4Rguc2bjw7Uug4GIJuu1tvf2uHaZv5Q8zdt+WKJ6qK1FOI6amaWUo5FA==
 
+pidtree@^0.6.0:
+  version "0.6.0"
+  resolved "https://registry.npmjs.org/pidtree/-/pidtree-0.6.0.tgz#90ad7b6d42d5841e69e0a2419ef38f8883aa057c"
+  integrity sha512-eG2dWTVw5bzqGRztnHExczNxt5VGsE6OwTeCG3fdUf9KBsZzO3R5OIIIzWR+iZA0NtZ+RDVdaoE2dK1cn6jH4g==
+
 pify@^2.2.0, pify@^2.3.0:
   version "2.3.0"
   resolved "https://registry.npmjs.org/pify/-/pify-2.3.0.tgz"