make it work correctly on linux

packages/playwright/src/plugins/webServerPlugin.ts

@@ -15,6 +15,7 @@
  */
 import path from 'path';
 import net from 'net';
+import child_process from 'child_process'
 
 import { colors, debug } from 'playwright-core/lib/utilsBundle';
 import { raceAgainstDeadline, launchProcess, monotonicTime, isURLAvailable } from 'playwright-core/lib/utils';
@@ -124,10 +125,18 @@ export class WebServerPlugin implements TestRunnerPlugin {
         if (!signal)
           throw new Error('skip graceful shutdown');
 
-        // launchedProcess is a shell. not all shells forward signals to their child processes.
+        if (signal === "SIGINT") // proper usage of SIGINT is to send it to the entire process group, see https://www.cons.org/cracauer/sigint.html
-        // we need to send the signal to the webserver inside the shell.
+          process.kill(-launchedProcess.pid!, "SIGINT");
-        const webserverPid = launchedProcess.pid!; // TODO: get the actual pid of the webserver
+        else { // SIGTERM is sent to the top process only, which then decides what to do
-        process.kill(webserverPid, signal);
+          let pid = launchedProcess.pid!;
+          if (process.platform === "linux") {
+            for (const webServerPID of this._queryChildProcesses(launchedProcess.pid!))
+              process.kill(webServerPID, 'SIGTERM');
+          } else {
+            process.kill(-pid, "SIGTERM");
+          }
+        }
+          
         return new Promise<void>((resolve, reject) => {
           const timer = timeout !== 0
             ? setTimeout(() => reject(new Error(`process didn't close gracefully within timeout, falling back to SIGKILL`)), timeout)
@@ -156,6 +165,11 @@ export class WebServerPlugin implements TestRunnerPlugin {
     });
   }
 
+  private _queryChildProcesses(parentPID: number): number[] {
+    const output = child_process.execSync(`ps --ppid ${parentPID} -o pid`, { encoding: 'utf-8' });
+    return output.split("\n").map(l => parseInt(l.trim(), 10)).filter(l => !Number.isNaN(l))
+  }
+
   private async _waitForProcess() {
     if (!this._isAvailableCallback) {
       this._processExitedPromise.catch(() => {});

tests/playwright-test/web-server.spec.ts

@@ -752,10 +752,23 @@ test.describe('kill option', () => {
   const files = (additionalOptions = {}) => {
     const port = test.info().workerIndex * 2 + 10510;
     return {
+      'child.js': `
+        process.on('SIGINT', () => { console.log('%%childprocess received SIGINT'); setTimeout(() => process.exit(), 10) })
+        process.on('SIGTERM', () => { console.log('%%childprocess received SIGTERM'); setTimeout(() => process.exit(), 10) })
+        process.on('message', msg => console.log(msg))
+      `,
       'web-server.js': `
-        process.on('SIGINT', () => { console.log('%%webserver received SIGINT but stubbornly refuses to wind down') })
+        const child = require("node:child_process").fork('./child.js', { silent: false })
-        process.on('SIGTERM', () => { console.log('%%webserver received SIGTERM but stubbornly refuses to wind down') })
+        
-        const server = require('http').createServer((req, res) => { res.end("ok"); })
+        process.on('SIGINT', () => {
+          console.log('%%webserver received SIGINT but stubbornly refuses to wind down')
+        })
+        process.on('SIGTERM', () => {
+          console.log('%%webserver received SIGTERM but stubbornly refuses to wind down')
+          child.kill('SIGINT')
+        })
+
+        const server = require("node:http").createServer((req, res) => { res.end("ok"); })
         server.listen(process.argv[2]);
       `,
       'test.spec.ts': `
@@ -765,7 +778,7 @@ test.describe('kill option', () => {
       'playwright.config.ts': `
         module.exports = {
           webServer: {
-            command: 'node web-server.js ${port}',
+            command: 'echo some-precondition && node web-server.js ${port}',
             port: ${port},
             stdout: 'pipe',
             timeout: 3000,
@@ -788,12 +801,12 @@ test.describe('kill option', () => {
 
   test('can be configured to send SIGTERM', async ({ runInlineTest }) => {
     const result = await runInlineTest(files({ kill: { SIGTERM: 500 } }), { workers: 1 });
-    expect(parseOutputLines(result)).toEqual(['webserver received SIGTERM but stubbornly refuses to wind down']);
+    expect(parseOutputLines(result)).toEqual(['webserver received SIGTERM but stubbornly refuses to wind down', 'childprocess received SIGINT']);
   });
 
   test('can be configured to send SIGINT', async ({ runInlineTest }) => {
-    const result = await runInlineTest(files({ kill: { SIGINT: 500 } }), { workers: 1 });
+    const result = await runInlineTest(files({ kill: { SIGINT: 5000 } }), { workers: 1 });
-    expect(parseOutputLines(result)).toEqual(['webserver received SIGINT but stubbornly refuses to wind down']);
+    expect(parseOutputLines(result).sort()).toEqual(['childprocess received SIGINT', 'webserver received SIGINT but stubbornly refuses to wind down']);
   });
 
   test('throws when mixed', async ({ runInlineTest }) => {