feat: add killAll function (#186)

README.md

@@ -112,6 +112,18 @@ Returns an `Array<string>` of paths to available Chrome installations. When `chr
 
 Note: This method performs synchronous I/O operations.
 
+### `.killAll()`
+
+Attempts to kill all Chrome instances created with [`.launch([opts])`](#launchopts). Returns a Promise that resolves to an array of errors that occurred while killing instances. If all instances were killed successfully, the array will be empty.
+
+```js
+const ChromeLauncher = require('chrome-launcher');
+
+async function cleanup() {
+  await ChromeLauncher.killAll();
+}
+```
+
 ## Examples
 
 #### Launching chrome:

src/chrome-launcher.ts

@@ -57,12 +57,7 @@ export interface ModuleOverrides {
 }
 
 const sigintListener = async () => {
-  for (const instance of instances) {
-    try {
-      await instance.kill();
-    } catch (err) {
-    }
-  }
+  await killAll();
   process.exit(_SIGINT_EXIT_CODE);
 };
 
@@ -90,6 +85,21 @@ async function launch(opts: Options = {}): Promise<LaunchedChrome> {
   return {pid: instance.pid!, port: instance.port!, kill, process: instance.chrome!};
 }
 
+async function killAll(): Promise<Array<Error>> {
+  let errors = [];
+  for (const instance of instances) {
+    try {
+      await instance.kill();
+      // only delete if kill did not error
+      // this means erroring instances remain in the Set
+      instances.delete(instance);
+    } catch (err) {
+      errors.push(err);
+    }
+  }
+  return errors;
+}
+
 class Launcher {
   private tmpDirandPidFileReady = false;
   private pidFile: string;
@@ -373,4 +383,4 @@ class Launcher {
 };
 
 export default Launcher;
-export {Launcher, launch};
+export {Launcher, launch, killAll};

test/chrome-launcher-test.ts

@@ -5,7 +5,7 @@
  */
 'use strict';
 
-import {Launcher, Options} from '../src/chrome-launcher';
+import {Launcher, launch, killAll, Options} from '../src/chrome-launcher';
 import {DEFAULT_FLAGS} from '../src/flags';
 
 import {spy, stub} from 'sinon';
@@ -98,6 +98,13 @@ describe('Launcher', () => {
     await chromeInstance.kill();
   });
 
+  it('doesn\'t fail when killing all instances', async () => {
+    await launch();
+    await launch();
+    const errors = await killAll();
+    assert.strictEqual(errors.length, 0);
+  });
+
   it('doesn\'t launch multiple chrome processes', async () => {
     const chromeInstance = new Launcher();
     await chromeInstance.launch();