wdio-local-runner: unpipe streams in the end (#3882)

* wdio-local-runner: unpipe streams in the end

* wdio-local-runner: transformStream _final test

packages/wdio-local-runner/src/transformStream.js

@@ -19,12 +19,8 @@ export default class RunnerTransformStream extends Transform {
         callback()
     }
 
-    _final () {
-        /**
-         * we don't want to do anything here otherwise we would end the
-         * stream of the local runner that captures stdout/stderr or all
-         * runners and therefor would loose all incoming messages after
-         * the first runner finishes.
-         */
+    _final (callback) {
+        this.unpipe()
+        callback()
     }
 }

packages/wdio-local-runner/tests/transformStream.test.js

@@ -1,27 +1,38 @@
 import RunnerTransformStream from '../src/transformStream'
 import { DEBUGGER_MESSAGES } from '../src/constants'
 
-jest.mock('stream', () => {
-    class TransformMock {
-        constructor () {
-            this.push = jest.fn()
-        }
-    }
-
-    return { Transform: TransformMock }
-})
-
 test('should add cid to message', () => {
     const stream = new RunnerTransformStream('0-5')
     const cb = jest.fn()
+    const pushSpy = jest.spyOn(stream, 'push')
+
     stream._transform('foobar', null, cb)
-    expect(stream.push).toBeCalledWith('[0-5] foobar')
+    expect(pushSpy).toBeCalledWith('[0-5] foobar')
     expect(cb).toBeCalled()
 })
 
 test('should ignore debugger messages', () => {
     const stream = new RunnerTransformStream('0-5')
     const cb = jest.fn()
+    const pushSpy = jest.spyOn(stream, 'push')
+
     DEBUGGER_MESSAGES.forEach(m => stream._transform(`${m} foobar`, null, cb))
-    expect(stream.push).toBeCalledTimes(0)
+    expect(pushSpy).toBeCalledTimes(0)
+})
+
+test('should ignore debugger messages', (done) => {
+    const stream = new RunnerTransformStream('0-5')
+    const stream2 = new RunnerTransformStream('0-6')
+
+    stream2.pipe(stream)
+    const cb = jest.fn()
+    stream.on('unpipe', cb)
+
+    const finalSpy = jest.spyOn(stream, '_final')
+
+    stream.end(() => {
+        expect(cb).toBeCalled()
+        expect(finalSpy).toBeCalled()
+        done()
+    })
 })