diff --git a/packages/api/src/test_framework/TestFramework.ts b/packages/api/src/test_framework/TestFramework.ts
index e64b4e4560..4da00e02a1 100644
--- a/packages/api/src/test_framework/TestFramework.ts
+++ b/packages/api/src/test_framework/TestFramework.ts
@@ -18,8 +18,8 @@ interface TestFramework {
 
   /**
    * Creates a code fragment which, if included in a test run,
-   * will be responsible for filtering out tests with given ids.
-   * The first test gets id 0, the second id 1, etc.
+   * will be responsible for filtering out tests with given test selector.
+   * If te test selection array is empty it should reset the filtering for the next test run.
    *
    * @param selections A list indicating the tests to select.
    * @returns A script which, if included in the test run, will filter out the correct tests.
diff --git a/packages/core/src/Sandbox.ts b/packages/core/src/Sandbox.ts
index f3c7b320be..9587343f31 100644
--- a/packages/core/src/Sandbox.ts
+++ b/packages/core/src/Sandbox.ts
@@ -197,8 +197,12 @@ export default class Sandbox {
   }
 
   private getFilterTestsHooks(mutant: TestableMutant): string | undefined {
-    if (this.testFramework && !mutant.runAllTests) {
-      return wrapInClosure(this.testFramework.filter(mutant.selectedTests));
+    if (this.testFramework) {
+      if (mutant.runAllTests) {
+        return wrapInClosure(this.testFramework.filter([]));
+      } else {
+        return wrapInClosure(this.testFramework.filter(mutant.selectedTests));
+      }
     } else {
       return undefined;
     }
diff --git a/packages/core/src/child-proxy/ChildProcessProxy.ts b/packages/core/src/child-proxy/ChildProcessProxy.ts
index bc80619aa3..876201d399 100644
--- a/packages/core/src/child-proxy/ChildProcessProxy.ts
+++ b/packages/core/src/child-proxy/ChildProcessProxy.ts
@@ -167,6 +167,10 @@ export default class ChildProcessProxy<T> implements Disposable {
     }
   }
 
+  public get stdout() {
+    return this.stdoutBuilder.toString();
+  }
+
   private reportError(error: Error) {
     this.workerTasks.filter(task => !task.isCompleted).forEach(task => task.reject(error));
   }
diff --git a/packages/core/test/integration/child-proxy/ChildProcessProxy.it.spec.ts b/packages/core/test/integration/child-proxy/ChildProcessProxy.it.spec.ts
index b1d0add8db..37ff5ce319 100644
--- a/packages/core/test/integration/child-proxy/ChildProcessProxy.it.spec.ts
+++ b/packages/core/test/integration/child-proxy/ChildProcessProxy.it.spec.ts
@@ -3,18 +3,15 @@ import * as path from 'path';
 import { File, LogLevel } from '@stryker-mutator/api/core';
 import { Logger } from '@stryker-mutator/api/logging';
 import { commonTokens } from '@stryker-mutator/api/plugin';
-import { testInjector } from '@stryker-mutator/test-helpers';
+import { testInjector, LoggingServer } from '@stryker-mutator/test-helpers';
 import { expect } from 'chai';
 import * as log4js from 'log4js';
 import { filter } from 'rxjs/operators';
 
-import getPort = require('get-port');
-
 import ChildProcessCrashedError from '../../../src/child-proxy/ChildProcessCrashedError';
 import ChildProcessProxy from '../../../src/child-proxy/ChildProcessProxy';
 import OutOfMemoryError from '../../../src/child-proxy/OutOfMemoryError';
 import { Task } from '../../../src/utils/Task';
-import LoggingServer from '../../helpers/LoggingServer';
 import currentLogMock from '../../helpers/logMock';
 import { Mock } from '../../helpers/producers';
 import { sleep } from '../../helpers/testUtils';
@@ -29,10 +26,10 @@ describe(ChildProcessProxy.name, () => {
   const workingDir = '..';
 
   beforeEach(async () => {
-    const port = await getPort();
+    loggingServer = new LoggingServer();
+    const port = await loggingServer.listen();
     const options = testInjector.injector.resolve(commonTokens.options);
     log = currentLogMock();
-    loggingServer = new LoggingServer(port);
     sut = ChildProcessProxy.create(require.resolve('./Echo'), { port, level: LogLevel.Debug }, options, { name: echoName }, workingDir, Echo);
   });
 
diff --git a/packages/core/test/integration/test-runner/ResilientTestRunnerFactory.it.spec.ts b/packages/core/test/integration/test-runner/ResilientTestRunnerFactory.it.spec.ts
index 1ceb6ffe7d..d16816febb 100644
--- a/packages/core/test/integration/test-runner/ResilientTestRunnerFactory.it.spec.ts
+++ b/packages/core/test/integration/test-runner/ResilientTestRunnerFactory.it.spec.ts
@@ -6,12 +6,10 @@ import { strykerOptions } from '@stryker-mutator/test-helpers/src/factory';
 import { expect } from 'chai';
 import * as log4js from 'log4js';
 import { toArray } from 'rxjs/operators';
-
-import getPort = require('get-port');
+import { LoggingServer } from '@stryker-mutator/test-helpers';
 
 import LoggingClientContext from '../../../src/logging/LoggingClientContext';
 import ResilientTestRunnerFactory from '../../../src/test-runner/ResilientTestRunnerFactory';
-import LoggingServer from '../../helpers/LoggingServer';
 import { sleep } from '../../helpers/testUtils';
 
 describe('ResilientTestRunnerFactory integration', () => {
@@ -25,8 +23,8 @@ describe('ResilientTestRunnerFactory integration', () => {
 
   beforeEach(async () => {
     // Make sure there is a logging server listening
-    const port = await getPort();
-    loggingServer = new LoggingServer(port);
+    loggingServer = new LoggingServer();
+    const port = await loggingServer.listen();
     loggingContext = { port, level: LogLevel.Trace };
     options = strykerOptions({
       plugins: [require.resolve('./AdditionalTestRunners')],
diff --git a/packages/core/test/unit/Sandbox.spec.ts b/packages/core/test/unit/Sandbox.spec.ts
index ce565988bf..0face9dd00 100644
--- a/packages/core/test/unit/Sandbox.spec.ts
+++ b/packages/core/test/unit/Sandbox.spec.ts
@@ -37,12 +37,11 @@ describe(Sandbox.name, () => {
   let options: Config;
   let inputFiles: File[];
   let testRunner: Mock<TestRunnerDecorator>;
-  let testFrameworkStub: any;
+  let testFrameworkStub: sinon.SinonStubbedInstance<TestFramework>;
   let expectedFileToMutate: File;
   let notMutatedFile: File;
   let sandboxDirectory: string;
   let expectedTargetFileToMutate: string;
-  let expectedTestFrameworkHooksFile: string;
   let writeFileStub: sinon.SinonStub;
   let symlinkJunctionStub: sinon.SinonStub;
   let findNodeModulesStub: sinon.SinonStub;
@@ -55,13 +54,14 @@ describe(Sandbox.name, () => {
     options = { timeoutFactor: 23, timeoutMS: 1000, testRunner: 'sandboxUnitTestRunner', symlinkNodeModules: true } as any;
     testRunner = { init: sinon.stub(), run: sinon.stub().resolves(runResult), dispose: sinon.stub() };
     testFrameworkStub = {
-      filter: sinon.stub()
+      filter: sinon.stub(),
+      afterEach: sinon.stub(),
+      beforeEach: sinon.stub()
     };
     expectedFileToMutate = new File(path.resolve('file1'), 'original code');
     notMutatedFile = new File(path.resolve('file2'), 'to be mutated');
     sandboxDirectory = path.resolve('random-folder-3');
     expectedTargetFileToMutate = path.join(sandboxDirectory, 'file1');
-    expectedTestFrameworkHooksFile = path.join(sandboxDirectory, '___testHooksForStryker.js');
     inputFiles = [expectedFileToMutate, notMutatedFile];
     temporaryDirectoryMock = sinon.createStubInstance(TemporaryDirectory);
     temporaryDirectoryMock.createRandomDirectory.returns(sandboxDirectory);
@@ -84,12 +84,12 @@ describe(Sandbox.name, () => {
     files: readonly File[];
   }
   function createSut(overrides?: Partial<CreateArgs>) {
-    const args: CreateArgs = {
+    const { files, testFramework, overheadTimeMS }: CreateArgs = {
       files: inputFiles,
       overheadTimeMS: OVERHEAD_TIME_MS,
-      testFramework: null
+      testFramework: null,
+      ...overrides
     };
-    const { files, testFramework, overheadTimeMS } = { ...args, ...overrides };
     return Sandbox.create(options, SANDBOX_INDEX, files, testFramework, overheadTimeMS, LOGGING_CONTEXT, temporaryDirectoryMock as any);
   }
 
@@ -112,19 +112,19 @@ describe(Sandbox.name, () => {
     });
 
     it('should have created a sandbox folder', async () => {
-      await createSut(testFrameworkStub);
+      await createSut({ testFramework: testFrameworkStub });
       expect(temporaryDirectoryMock.createRandomDirectory).calledWith('sandbox');
     });
 
     it('should symlink node modules in sandbox directory if exists', async () => {
-      await createSut(testFrameworkStub);
+      await createSut({ testFramework: testFrameworkStub });
       expect(findNodeModulesStub).calledWith(process.cwd());
       expect(symlinkJunctionStub).calledWith('node_modules', path.join(sandboxDirectory, 'node_modules'));
     });
 
     it('should not symlink node modules in sandbox directory if no node_modules exist', async () => {
       findNodeModulesStub.resolves(null);
-      await createSut(testFrameworkStub);
+      await createSut({ testFramework: testFrameworkStub });
       expect(log.warn).calledWithMatch('Could not find a node_modules');
       expect(log.warn).calledWithMatch(process.cwd());
       expect(symlinkJunctionStub).not.called;
@@ -133,7 +133,7 @@ describe(Sandbox.name, () => {
     it('should log a warning if "node_modules" already exists in the working folder', async () => {
       findNodeModulesStub.resolves('node_modules');
       symlinkJunctionStub.rejects(fileAlreadyExistsError());
-      await createSut(testFrameworkStub);
+      await createSut({ testFramework: testFrameworkStub });
       expect(log.warn).calledWithMatch(
         normalizeWhitespaces(
           `Could not symlink "node_modules" in sandbox directory, it is already created in the sandbox.
@@ -147,7 +147,7 @@ describe(Sandbox.name, () => {
       findNodeModulesStub.resolves('basePath/node_modules');
       const error = new Error('unknown');
       symlinkJunctionStub.rejects(error);
-      await createSut(testFrameworkStub);
+      await createSut({ testFramework: testFrameworkStub });
       expect(log.warn).calledWithMatch(
         normalizeWhitespaces('Unexpected error while trying to symlink "basePath/node_modules" in sandbox directory.'),
         error
@@ -156,7 +156,7 @@ describe(Sandbox.name, () => {
 
     it('should symlink node modules in sandbox directory if `symlinkNodeModules` is `false`', async () => {
       options.symlinkNodeModules = false;
-      await createSut(testFrameworkStub);
+      await createSut({ testFramework: testFrameworkStub });
       expect(symlinkJunctionStub).not.called;
       expect(findNodeModulesStub).not.called;
     });
@@ -229,6 +229,7 @@ describe(Sandbox.name, () => {
       const sut = await createSut({ testFramework: testFrameworkStub });
       await sut.runMutant(transpiledMutant);
       expect(testFrameworkStub.filter).to.have.been.calledWith(transpiledMutant.mutant.selectedTests);
+      expect(testRunner.run).calledWithMatch({ testHooks: wrapInClosure(testFilterCodeFragment) });
     });
 
     it('should provide the filter code as testHooks, correct timeout and mutatedFileName', async () => {
@@ -254,32 +255,25 @@ describe(Sandbox.name, () => {
     });
 
     it('should not filter any tests when testFramework = null', async () => {
+      transpiledMutant.mutant.selectAllTests(runResult, TestSelectionResult.Success);
       const sut = await createSut();
-      const mutant = new TestableMutant('2', createMutant(), new SourceFile(new File('', '')));
-      await sut.runMutant(new TranspiledMutant(mutant, { outputFiles: [new File(expectedTargetFileToMutate, '')], error: null }, true));
-      expect(fileUtils.writeFile).not.calledWith(expectedTestFrameworkHooksFile);
+      await sut.runMutant(transpiledMutant);
+      expect(testRunner.run).calledWithMatch({ testHooks: undefined });
     });
 
-    it('should not filter any tests when runAllTests = true', async () => {
+    it('should filter no tests when runAllTests = true', async () => {
       // Arrange
       while (transpiledMutant.mutant.selectedTests.pop());
       transpiledMutant.mutant.selectAllTests(runResult, TestSelectionResult.Success);
-      const sut = await createSut();
+      testFrameworkStub.filter.returns('empty filter');
+      const sut = await createSut({ testFramework: testFrameworkStub });
 
       // Act
       await sut.runMutant(transpiledMutant);
 
       // Assert
-      expect(fileUtils.writeFile).not.calledWith(expectedTestFrameworkHooksFile);
-      expect(testRunner.run).called;
-    });
-
-    it('should not filter any tests when runAllTests = true', async () => {
-      const sut = await createSut();
-      const mutant = new TestableMutant('2', createMutant(), new SourceFile(new File('', '')));
-      mutant.selectAllTests(runResult, TestSelectionResult.Failed);
-      sut.runMutant(new TranspiledMutant(mutant, { outputFiles: [new File(expectedTargetFileToMutate, '')], error: null }, true));
-      expect(fileUtils.writeFile).not.calledWith(expectedTestFrameworkHooksFile);
+      expect(testRunner.run).calledWithMatch({ testHooks: wrapInClosure('empty filter') });
+      expect(testFrameworkStub.filter).calledWith([]);
     });
 
     it('should report a runtime error when test run errored', async () => {
diff --git a/packages/jasmine-framework/src/JasmineTestFramework.ts b/packages/jasmine-framework/src/JasmineTestFramework.ts
index 55ea7049a8..6f0d1b5baf 100644
--- a/packages/jasmine-framework/src/JasmineTestFramework.ts
+++ b/packages/jasmine-framework/src/JasmineTestFramework.ts
@@ -28,10 +28,14 @@ export default class JasmineTestFramework implements TestFramework {
   }
 
   public filter(testSelections: TestSelection[]): string {
-    const names = testSelections.map(selection => selection.name);
-    return `
+    if (testSelections.length) {
+      const names = testSelections.map(selection => selection.name);
+      return `
       jasmine.getEnv().specFilter = function (spec) {
           return ${JSON.stringify(names)}.indexOf(spec.getFullName()) !== -1;
       }`;
+    } else {
+      return '';
+    }
   }
 }
diff --git a/packages/jasmine-framework/test/unit/JasmineTestFramework.spec.ts b/packages/jasmine-framework/test/unit/JasmineTestFramework.spec.ts
index 6a4c794e67..1c11efd486 100644
--- a/packages/jasmine-framework/test/unit/JasmineTestFramework.spec.ts
+++ b/packages/jasmine-framework/test/unit/JasmineTestFramework.spec.ts
@@ -21,7 +21,7 @@ describe('JasmineTestFramework', () => {
   });
 
   describe('filter()', () => {
-    it("should result in a specFilter of jasmine it's", () =>
+    it("should result in a specFilter of jasmine it's", () => {
       expect(
         sut.filter([
           { id: 5, name: 'test five' },
@@ -29,6 +29,11 @@ describe('JasmineTestFramework', () => {
         ])
       )
         .to.contain('jasmine.getEnv().specFilter = function (spec)')
-        .and.to.contain('return ["test five","test eight"].indexOf(spec.getFullName()) !== -1;'));
+        .and.to.contain('return ["test five","test eight"].indexOf(spec.getFullName()) !== -1;');
+    });
+
+    it('should result in an empty string when filter is empty', () => {
+      expect(sut.filter([])).eq('');
+    });
   });
 });
diff --git a/packages/jasmine-runner/test/integration/JasmineRunner.it.spec.ts b/packages/jasmine-runner/test/integration/JasmineRunner.it.spec.ts
index 884ce2fb3b..3c35f7913b 100644
--- a/packages/jasmine-runner/test/integration/JasmineRunner.it.spec.ts
+++ b/packages/jasmine-runner/test/integration/JasmineRunner.it.spec.ts
@@ -99,6 +99,17 @@ describe('JasmineRunner integration', () => {
       expectTestsFiltered(runResult.tests, 1, 3);
     });
 
+    it('should be able to clear the filter after a filtered run', async () => {
+      // Arrange
+      const testFramework = new JasmineTestFramework();
+      const filter1Test = wrapInClosure(testFramework.filter([{ id: 1, name: expectedJasmineInitResults[1].name }]));
+      const filterNoTests = wrapInClosure(testFramework.filter([]));
+
+      await sut.run({ testHooks: filter1Test });
+      const actualResult = await sut.run({ testHooks: filterNoTests });
+      expectTestResultsToEqual(actualResult.tests, expectedJasmineInitResults);
+    });
+
     it('should be able to filter tests in quick succession', async () => {
       // Arrange
       const testFramework = new JasmineTestFramework();
diff --git a/packages/karma-runner/package.json b/packages/karma-runner/package.json
index 8c0e55f2c6..6360256b31 100644
--- a/packages/karma-runner/package.json
+++ b/packages/karma-runner/package.json
@@ -5,7 +5,9 @@
   "main": "src/index.js",
   "scripts": {
     "test": "nyc --exclude-after-remap=false --check-coverage --reporter=html --report-dir=reports/coverage --lines 80 --functions 80 --branches 75 npm run mocha",
-    "mocha": "mocha \"test/helpers/**/*.js\" \"test/unit/**/*.js\" && mocha --timeout 30000 --exit \"test/helpers/**/*.js\" \"test/integration/**/*.js\"",
+    "mocha": "npm run test:unit && npm run test:integration",
+    "test:unit": "mocha \"test/helpers/**/*.js\" \"test/unit/**/*.js\"",
+    "test:integration": "mocha --timeout 30000 --exit \"test/helpers/**/*.js\" \"test/integration/**/*.js\"",
     "stryker": "node ../core/bin/stryker run"
   },
   "repository": {
@@ -37,8 +39,10 @@
     "@types/semver": "~7.1.0",
     "jasmine-core": "~3.5.0",
     "karma": "~4.1.0",
+    "karma-chai": "^0.1.0",
     "karma-jasmine": "~3.0.1",
-    "karma-phantomjs-launcher": "~1.0.4"
+    "karma-mocha": "^1.3.0",
+    "karma-phantomjs-launcher": "^1.0.4"
   },
   "peerDependencies": {
     "@stryker-mutator/core": "^2.0.0"
diff --git a/packages/karma-runner/test/integration/KarmaTestRunner.it.spec.ts b/packages/karma-runner/test/integration/KarmaTestRunner.it.spec.ts
index c1567f0315..bcc09f7b92 100644
--- a/packages/karma-runner/test/integration/KarmaTestRunner.it.spec.ts
+++ b/packages/karma-runner/test/integration/KarmaTestRunner.it.spec.ts
@@ -6,9 +6,11 @@ import JasmineTestFramework from '@stryker-mutator/jasmine-framework/src/Jasmine
 import { testInjector } from '@stryker-mutator/test-helpers';
 import { expect } from 'chai';
 import { FilePattern } from 'karma';
+import { TestSelection } from '@stryker-mutator/api/test_framework';
 
 import KarmaTestRunner from '../../src/KarmaTestRunner';
 import { expectTestResults } from '../helpers/assertions';
+import MochaTestFramework from '../../../mocha-framework/src/MochaTestFramework';
 
 function wrapInClosure(codeFragment: string) {
   return `
@@ -17,7 +19,13 @@ function wrapInClosure(codeFragment: string) {
     })((Function('return this'))());`;
 }
 
-function setOptions(files: ReadonlyArray<FilePattern | string>, coverageAnalysis: 'all' | 'perTest' | 'off' = 'off'): void {
+function setOptions(
+  files: ReadonlyArray<FilePattern | string> = [
+    'testResources/sampleProject/src-instrumented/Add.js',
+    'testResources/sampleProject/test-jasmine/AddSpec.js'
+  ],
+  coverageAnalysis: 'all' | 'perTest' | 'off' = 'off'
+): void {
   testInjector.options.coverageAnalysis = coverageAnalysis;
   testInjector.options.karma = {
     config: {
@@ -32,7 +40,7 @@ function createSut() {
   return testInjector.injector.injectClass(KarmaTestRunner);
 }
 
-describe('KarmaTestRunner', () => {
+describe(`${KarmaTestRunner.name} integration`, () => {
   let sut: KarmaTestRunner;
 
   const expectToHaveSuccessfulTests = (result: RunResult, n: number) => {
@@ -47,10 +55,54 @@ describe('KarmaTestRunner', () => {
     });
   };
 
+  describe('with mocha', () => {
+    let testFramework: MochaTestFramework;
+
+    const test0: Readonly<TestSelection> = Object.freeze({
+      id: 0,
+      name: 'Add should be able to add two numbers'
+    });
+
+    const test3: Readonly<TestSelection> = {
+      id: 3,
+      name: 'Add should be able to recognize a negative number'
+    };
+
+    before(() => {
+      testFramework = new MochaTestFramework();
+      setOptions(['testResources/sampleProject/src/Add.js', 'testResources/sampleProject/test-mocha/AddSpec.js']);
+      testInjector.options.karma.config.frameworks = ['mocha', 'chai'];
+      sut = createSut();
+      return sut.init();
+    });
+
+    it('should report completed tests', async () => {
+      const runResult = await sut.run({});
+      // await new Promise(res => {});
+      expectToHaveSuccessfulTests(runResult, 5);
+      expectToHaveFailedTests(runResult, []);
+      expect(runResult.status).to.be.eq(RunStatus.Complete);
+    });
+
+    it('should be able to filter tests', async () => {
+      const testHooks = wrapInClosure(testFramework.filter([test0, test3]));
+      const actualResult = await sut.run({ testHooks });
+      expectToHaveSuccessfulTests(actualResult, 2);
+      expect(actualResult.tests[0].name).eq(test0.name);
+      expect(actualResult.tests[1].name).eq(test3.name);
+    });
+
+    it('should be able to clear the filter after a filtered run', async () => {
+      await sut.run({ testHooks: wrapInClosure(testFramework.filter([test0, test3])) });
+      const actualResult = await sut.run({ testHooks: wrapInClosure(testFramework.filter([])) });
+      expect(actualResult.tests).lengthOf(5);
+    });
+  });
+
   describe('when all tests succeed', () => {
     describe('with simple add function to test', () => {
       before(() => {
-        setOptions(['testResources/sampleProject/src/Add.js', 'testResources/sampleProject/test/AddSpec.js']);
+        setOptions(['testResources/sampleProject/src/Add.js', 'testResources/sampleProject/test-jasmine/AddSpec.js']);
         sut = createSut();
         return sut.init();
       });
@@ -90,8 +142,8 @@ describe('KarmaTestRunner', () => {
     before(() => {
       setOptions([
         'testResources/sampleProject/src/Add.js',
-        'testResources/sampleProject/test/AddSpec.js',
-        'testResources/sampleProject/test/AddFailedSpec.js'
+        'testResources/sampleProject/test-jasmine/AddSpec.js',
+        'testResources/sampleProject/test-jasmine/AddFailedSpec.js'
       ]);
       sut = createSut();
       return sut.init();
@@ -112,7 +164,7 @@ describe('KarmaTestRunner', () => {
       setOptions([
         'testResources/sampleProject/src/Add.js',
         'testResources/sampleProject/src/Error.js',
-        'testResources/sampleProject/test/AddSpec.js'
+        'testResources/sampleProject/test-jasmine/AddSpec.js'
       ]);
       sut = createSut();
       return sut.init();
@@ -128,7 +180,7 @@ describe('KarmaTestRunner', () => {
 
   describe('when no error occurred and no test is performed', () => {
     before(() => {
-      setOptions(['testResources/sampleProject/src/Add.js', 'testResources/sampleProject/test/EmptySpec.js']);
+      setOptions(['testResources/sampleProject/src/Add.js', 'testResources/sampleProject/test-jasmine/EmptySpec.js']);
       sut = createSut();
       return sut.init();
     });
@@ -149,7 +201,7 @@ describe('KarmaTestRunner', () => {
     before(() => {
       setOptions([
         { pattern: 'testResources/sampleProject/src/Add.js', included: true },
-        { pattern: 'testResources/sampleProject/test/AddSpec.js', included: true },
+        { pattern: 'testResources/sampleProject/test-jasmine/AddSpec.js', included: true },
         { pattern: 'testResources/sampleProject/src/Error.js', included: false }
       ]);
       sut = createSut();
@@ -166,7 +218,7 @@ describe('KarmaTestRunner', () => {
 
   describe('when coverage data is available', () => {
     before(() => {
-      setOptions(['testResources/sampleProject/src-instrumented/Add.js', 'testResources/sampleProject/test/AddSpec.js'], 'all');
+      setOptions(['testResources/sampleProject/src-instrumented/Add.js', 'testResources/sampleProject/test-jasmine/AddSpec.js'], 'all');
       sut = createSut();
       return sut.init();
     });
@@ -187,7 +239,8 @@ describe('KarmaTestRunner', () => {
 
     before(async () => {
       dummyServer = await DummyServer.create();
-      sut = testInjector.injector.injectClass(KarmaTestRunner);
+      setOptions();
+      sut = createSut();
       return sut.init();
     });
 
diff --git a/packages/karma-runner/testResources/sampleProject/karma.conf.js b/packages/karma-runner/testResources/sampleProject/karma.conf.js
index 069da0d5ba..44a0bed8f8 100644
--- a/packages/karma-runner/testResources/sampleProject/karma.conf.js
+++ b/packages/karma-runner/testResources/sampleProject/karma.conf.js
@@ -4,7 +4,7 @@ module.exports = function (config) {
   config.set({
     files: [
       __dirname + '/src/*.js',
-      __dirname + '/test/*.js'
+      __dirname + '/test-jasmine/*.js'
     ],
     exclude: [
       __dirname + '/src/Error.js',
@@ -19,4 +19,4 @@ module.exports = function (config) {
       'PhantomJS'
     ]
   });
-}
\ No newline at end of file
+}
diff --git a/packages/karma-runner/testResources/sampleProject/test/AddFailedSpec.js b/packages/karma-runner/testResources/sampleProject/test-jasmine/AddFailedSpec.js
similarity index 100%
rename from packages/karma-runner/testResources/sampleProject/test/AddFailedSpec.js
rename to packages/karma-runner/testResources/sampleProject/test-jasmine/AddFailedSpec.js
diff --git a/packages/karma-runner/testResources/sampleProject/test/AddSpec.js b/packages/karma-runner/testResources/sampleProject/test-jasmine/AddSpec.js
similarity index 100%
rename from packages/karma-runner/testResources/sampleProject/test/AddSpec.js
rename to packages/karma-runner/testResources/sampleProject/test-jasmine/AddSpec.js
diff --git a/packages/karma-runner/testResources/sampleProject/test/CircleSpec.js b/packages/karma-runner/testResources/sampleProject/test-jasmine/CircleSpec.js
similarity index 100%
rename from packages/karma-runner/testResources/sampleProject/test/CircleSpec.js
rename to packages/karma-runner/testResources/sampleProject/test-jasmine/CircleSpec.js
diff --git a/packages/karma-runner/testResources/sampleProject/test/EmptySpec.js b/packages/karma-runner/testResources/sampleProject/test-jasmine/EmptySpec.js
similarity index 100%
rename from packages/karma-runner/testResources/sampleProject/test/EmptySpec.js
rename to packages/karma-runner/testResources/sampleProject/test-jasmine/EmptySpec.js
diff --git a/packages/karma-runner/testResources/sampleProject/test/FailingAddSpec.js b/packages/karma-runner/testResources/sampleProject/test-jasmine/FailingAddSpec.js
similarity index 100%
rename from packages/karma-runner/testResources/sampleProject/test/FailingAddSpec.js
rename to packages/karma-runner/testResources/sampleProject/test-jasmine/FailingAddSpec.js
diff --git a/packages/karma-runner/testResources/sampleProject/test-mocha/AddSpec.js b/packages/karma-runner/testResources/sampleProject/test-mocha/AddSpec.js
new file mode 100644
index 0000000000..7a2f8ad628
--- /dev/null
+++ b/packages/karma-runner/testResources/sampleProject/test-mocha/AddSpec.js
@@ -0,0 +1,48 @@
+describe('Add', function () {
+  it('should be able to add two numbers', function () {
+    var num1 = 2;
+    var num2 = 5;
+    var expected = num1 + num2;
+
+    var actual = add(num1, num2);
+
+    expect(actual).eq(expected);
+    window.setTimeout(function () {
+      done();
+    }, 20);
+  });
+
+  it('should be able 1 to a number', function () {
+    var number = 2;
+    var expected = 3;
+
+    var actual = addOne(number);
+
+    expect(actual).eq(expected);
+  });
+
+  it('should be able negate a number', function () {
+    var number = 2;
+    var expected = -2;
+
+    var actual = negate(number);
+
+    expect(actual).eq(expected);
+  });
+
+  it('should be able to recognize a negative number', function () {
+    var number = -2;
+
+    var isNegative = isNegativeNumber(number);
+
+    expect(isNegative).eq(true);
+  });
+
+  it('should be able to recognize that 0 is not a negative number', function () {
+    var number = 0;
+
+    var isNegative = isNegativeNumber(number);
+
+    expect(isNegative).eq(false);
+  });
+});
diff --git a/packages/karma-runner/tsconfig.test.json b/packages/karma-runner/tsconfig.test.json
index 1a212580d7..ae773b007d 100644
--- a/packages/karma-runner/tsconfig.test.json
+++ b/packages/karma-runner/tsconfig.test.json
@@ -18,6 +18,9 @@
     },
     {
       "path": "../test-helpers/tsconfig.src.json"
+    },
+    {
+      "path": "../mocha-framework/tsconfig.src.json"
     }
   ]
-}
\ No newline at end of file
+}
diff --git a/packages/mocha-framework/package.json b/packages/mocha-framework/package.json
index 95c721b731..4ea707bd69 100644
--- a/packages/mocha-framework/package.json
+++ b/packages/mocha-framework/package.json
@@ -43,6 +43,7 @@
     "mocha": ">= 2.3.3 < 7"
   },
   "dependencies": {
-    "@stryker-mutator/api": "^2.5.0"
+    "@stryker-mutator/api": "^2.5.0",
+    "@stryker-mutator/util": "^2.5.0"
   }
 }
diff --git a/packages/mocha-framework/src/MochaTestFramework.ts b/packages/mocha-framework/src/MochaTestFramework.ts
index e83840d9e8..721c736658 100644
--- a/packages/mocha-framework/src/MochaTestFramework.ts
+++ b/packages/mocha-framework/src/MochaTestFramework.ts
@@ -1,5 +1,14 @@
 import { TestFramework, TestSelection } from '@stryker-mutator/api/test_framework';
 
+const FILTER_HEADER_FRAGMENT = `
+  var Mocha = window.Mocha || require('mocha');
+  var describe = Mocha.describe;`;
+const FILTER_RESET = `${FILTER_HEADER_FRAGMENT}
+  if (window.____mochaAddTest) {
+    Mocha.Suite.prototype.addTest = window.____mochaAddTest;
+  }
+`;
+
 export default class MochaTestFramework implements TestFramework {
   public beforeEach(codeFragment: string): string {
     return `beforeEach(function() {
@@ -14,9 +23,9 @@ export default class MochaTestFramework implements TestFramework {
   }
 
   public filter(testSelections: TestSelection[]) {
-    const selectedTestNames = testSelections.map(selection => selection.name);
-    return `var Mocha = window.Mocha || require('mocha');
-      var describe = Mocha.describe;
+    if (testSelections.length) {
+      const selectedTestNames = testSelections.map(selection => selection.name);
+      return `${FILTER_HEADER_FRAGMENT}
       var selectedTestNames = ${JSON.stringify(selectedTestNames)};
       if (window.____mochaAddTest) {
         Mocha.Suite.prototype.addTest = window.____mochaAddTest;
@@ -28,9 +37,12 @@ export default class MochaTestFramework implements TestFramework {
       Mocha.Suite.prototype.addTest = function (test) {
         // Only actually add the tests with the expected names
         var name = this.fullTitle() + ' ' + test.title;
-        if(selectedTestNames.indexOf(name) !== -1) {
+        if(!selectedTestNames.length || selectedTestNames.indexOf(name) !== -1) {
           realAddTest.apply(this, arguments);
         }
       };`;
+    } else {
+      return FILTER_RESET;
+    }
   }
 }
diff --git a/packages/mocha-framework/test/unit/MochaTestFramework.spec.ts b/packages/mocha-framework/test/unit/MochaTestFramework.spec.ts
index 26d60e9335..32d42a4709 100644
--- a/packages/mocha-framework/test/unit/MochaTestFramework.spec.ts
+++ b/packages/mocha-framework/test/unit/MochaTestFramework.spec.ts
@@ -1,4 +1,5 @@
 import { expect } from 'chai';
+import { normalizeWhitespaces } from '@stryker-mutator/util';
 
 import MochaTestFramework from '../../src/MochaTestFramework';
 
@@ -29,9 +30,21 @@ describe('MochaTestFramework', () => {
         ])
       )
         .to.contain('var realAddTest = Mocha.Suite.prototype.addTest;')
+        .to.contain("var Mocha = window.Mocha || require('mocha');")
         .and.to.contain('selectedTestNames = ["test five","test eight"];')
-        .and.to.contain('if(selectedTestNames.indexOf(name) !== -1)')
+        .and.to.contain('if(!selectedTestNames.length || selectedTestNames.indexOf(name) !== -1)')
         .and.to.contain('realAddTest.apply(this, arguments);');
     });
+    it('should result in a filter reset when selecting no tests', () => {
+      const actualFilter = normalizeWhitespaces(sut.filter([]));
+      const expectedFilter = normalizeWhitespaces(`
+        var Mocha = window.Mocha || require('mocha');
+        var describe = Mocha.describe;
+        if (window.____mochaAddTest) {
+          Mocha.Suite.prototype.addTest = window.____mochaAddTest;
+        }
+      `);
+      expect(actualFilter).eq(expectedFilter);
+    });
   });
 });
diff --git a/packages/mocha-framework/tsconfig.test.json b/packages/mocha-framework/tsconfig.test.json
index 6931176018..d7eab70bef 100644
--- a/packages/mocha-framework/tsconfig.test.json
+++ b/packages/mocha-framework/tsconfig.test.json
@@ -13,6 +13,9 @@
   "references": [
     {
       "path": "./tsconfig.src.json"
+    },
+    {
+      "path": "../util/tsconfig.src.json"
     }
   ]
-}
\ No newline at end of file
+}
diff --git a/packages/mocha-runner/package.json b/packages/mocha-runner/package.json
index e413549fa6..4c8b543a69 100644
--- a/packages/mocha-runner/package.json
+++ b/packages/mocha-runner/package.json
@@ -5,7 +5,9 @@
   "main": "src/index.js",
   "scripts": {
     "test": "nyc --exclude-after-remap=false --check-coverage --reporter=html --report-dir=reports/coverage --lines 80 --functions 80 --branches 75 npm run mocha",
-    "mocha": "mocha \"test/helpers/**/*.js\" \"test/unit/**/*.js\" && mocha --timeout 10000 \"test/helpers/**/*.js\" \"test/integration/**/*.js\"",
+    "mocha": "npm run test:unit && npm run test:integration",
+    "test:unit": "mocha \"test/helpers/**/*.js\" \"test/unit/**/*.js\"",
+    "test:integration": "mocha --no-timeout \"test/helpers/**/*.js\" \"test/integration/**/*.js\"",
     "stryker": "node ../core/bin/stryker run"
   },
   "repository": {
@@ -41,7 +43,7 @@
   "devDependencies": {
     "@stryker-mutator/test-helpers": "^2.5.0",
     "@types/multimatch": "~4.0.0",
-    "stryker-mocha-framework": "^0.15.1"
+    "@stryker-mutator/mocha-framework": "^2.5.0"
   },
   "peerDependencies": {
     "@stryker-mutator/core": "^2.0.0",
diff --git a/packages/mocha-runner/src/MochaTestRunner.ts b/packages/mocha-runner/src/MochaTestRunner.ts
index f90b95968a..954f64ae74 100644
--- a/packages/mocha-runner/src/MochaTestRunner.ts
+++ b/packages/mocha-runner/src/MochaTestRunner.ts
@@ -12,7 +12,7 @@ import { evalGlobal, mochaOptionsKey } from './utils';
 
 const DEFAULT_TEST_PATTERN = 'test/**/*.js';
 
-export default class MochaTestRunner implements TestRunner {
+export class MochaTestRunner implements TestRunner {
   private testFileNames: string[];
   private readonly mochaOptions: MochaOptions;
 
diff --git a/packages/mocha-runner/src/index.ts b/packages/mocha-runner/src/index.ts
index 173c5d841f..f8457ca39f 100644
--- a/packages/mocha-runner/src/index.ts
+++ b/packages/mocha-runner/src/index.ts
@@ -2,7 +2,7 @@ import { BaseContext, commonTokens, declareClassPlugin, declareFactoryPlugin, In
 
 import MochaConfigEditor from './MochaConfigEditor';
 import MochaOptionsLoader from './MochaOptionsLoader';
-import MochaTestRunner from './MochaTestRunner';
+import { MochaTestRunner } from './MochaTestRunner';
 
 export const strykerPlugins = [
   declareFactoryPlugin(PluginKind.ConfigEditor, 'mocha-runner', mochaConfigEditorFactory),
diff --git a/packages/mocha-runner/test/integration/MochaFileResolving.spec.ts b/packages/mocha-runner/test/integration/MochaFileResolving.spec.ts
index bd9b526dad..f9129765e5 100644
--- a/packages/mocha-runner/test/integration/MochaFileResolving.spec.ts
+++ b/packages/mocha-runner/test/integration/MochaFileResolving.spec.ts
@@ -5,7 +5,7 @@ import { expect } from 'chai';
 import { testInjector } from '@stryker-mutator/test-helpers';
 
 import MochaOptionsLoader from '../../src/MochaOptionsLoader';
-import MochaTestRunner from '../../src/MochaTestRunner';
+import { MochaTestRunner } from '../../src/MochaTestRunner';
 import { mochaOptionsKey } from '../../src/utils';
 
 describe('Mocha 6 file resolving integration', () => {
diff --git a/packages/mocha-runner/test/integration/MochaFramework.it.spec.ts b/packages/mocha-runner/test/integration/MochaFramework.it.spec.ts
index dfbcc69bee..7a58f7a450 100644
--- a/packages/mocha-runner/test/integration/MochaFramework.it.spec.ts
+++ b/packages/mocha-runner/test/integration/MochaFramework.it.spec.ts
@@ -1,11 +1,15 @@
-import { fork } from 'child_process';
+import * as path from 'path';
 
 import { TestSelection } from '@stryker-mutator/api/test_framework';
-import { RunResult, RunStatus, TestStatus } from '@stryker-mutator/api/test_runner';
+import { TestStatus, RunStatus } from '@stryker-mutator/api/test_runner';
 import { expect } from 'chai';
-import MochaTestFramework from 'stryker-mocha-framework/src/MochaTestFramework';
+import { LoggingServer, testInjector } from '@stryker-mutator/test-helpers';
+import MochaTestFramework from '@stryker-mutator/mocha-framework/src/MochaTestFramework';
+import { LogLevel } from '@stryker-mutator/api/core';
+import { commonTokens } from '@stryker-mutator/api/plugin';
 
-import { AUTO_START_ARGUMENT, RunMessage } from './MochaTestFrameworkIntegrationTestWorker';
+import ChildProcessProxy from '../../../core/src/child-proxy/ChildProcessProxy';
+import { MochaTestRunner } from '../../src/MochaTestRunner';
 
 const test0: Readonly<TestSelection> = Object.freeze({
   id: 0,
@@ -23,17 +27,45 @@ export function wrapInClosure(codeFragment: string) {
     })((Function('return this'))());`;
 }
 
-describe('Integration with stryker-mocha-framework', () => {
+describe('Integration with @stryker-mutator/mocha-framework', () => {
   let testFramework: MochaTestFramework;
+  let loggingServer: LoggingServer;
+  let sut: ChildProcessProxy<MochaTestRunner>;
 
-  beforeEach(() => {
+  beforeEach(async () => {
     testFramework = new MochaTestFramework();
+    loggingServer = new LoggingServer();
+    const resolveSampleProject: typeof path.resolve = path.resolve.bind(path, __dirname, '../../testResources/sampleProject');
+    const port = await loggingServer.listen();
+    testInjector.options.mochaOptions = {
+      file: [],
+      ignore: [],
+      spec: [resolveSampleProject('MyMathSpec.js')]
+    };
+    testInjector.options.plugins = [];
+
+    sut = ChildProcessProxy.create(
+      require.resolve('../../src/MochaTestRunner'),
+      { level: LogLevel.Trace, port },
+      testInjector.options,
+      {
+        [commonTokens.sandboxFileNames]: [resolveSampleProject('MyMath.js'), resolveSampleProject('MyMathSpec.js')]
+      },
+      __dirname,
+      MochaTestRunner
+    );
+    await sut.proxy.init();
   });
 
-  it('should be able to select only test 0 and 3 to run', async () => {
+  afterEach(async () => {
+    await sut.dispose();
+    await loggingServer.dispose();
+  });
+
+  it('should be able to filter tests', async () => {
     const testHooks = wrapInClosure(testFramework.filter([test0, test3]));
-    const actualProcessOutput = await actRun(testHooks);
-    expect(actualProcessOutput.result.tests.map(test => ({ name: test.name, status: test.status }))).deep.eq([
+    const actualResult = await sut.proxy.run({ testHooks });
+    expect(actualResult.tests.map(test => ({ name: test.name, status: test.status }))).deep.eq([
       {
         name: 'MyMath should be able to add two numbers',
         status: TestStatus.Success
@@ -45,39 +77,19 @@ describe('Integration with stryker-mocha-framework', () => {
     ]);
   });
 
+  it('should be able to clear the filter after a filtered run', async () => {
+    await sut.proxy.run({ testHooks: wrapInClosure(testFramework.filter([test0, test3])) });
+    const actualResult = await sut.proxy.run({ testHooks: wrapInClosure(testFramework.filter([])) });
+    expect(actualResult.tests).lengthOf(5);
+  });
+
   it('should be able to run beforeEach and afterEach', async () => {
     const testHooks = wrapInClosure(
       testFramework.beforeEach('console.log("beforeEach from hook");') + testFramework.afterEach('console.log("afterEach from hook");')
     );
-    const actualProcessOutput = await actRun(testHooks);
-    expect(actualProcessOutput.result.status).eq(RunStatus.Complete);
-    expect(actualProcessOutput.stdout).includes('beforeEach from hook');
-    expect(actualProcessOutput.stdout).includes('afterEach from hook');
+    const actualProcessOutput = await sut.proxy.run({ testHooks });
+    expect(actualProcessOutput.status).eq(RunStatus.Complete);
+    expect(sut.stdout).includes('beforeEach from hook');
+    expect(sut.stdout).includes('afterEach from hook');
   });
-
-  function actRun(testHooks: string | undefined): Promise<{ result: RunResult; stdout: string }> {
-    return new Promise<{ result: RunResult; stdout: string }>((resolve, reject) => {
-      const sutProxy = fork(require.resolve('./MochaTestFrameworkIntegrationTestWorker'), [AUTO_START_ARGUMENT], {
-        execArgv: [],
-        silent: true
-      });
-      let stdout: string = '';
-      sutProxy.stdout.on('data', chunk => (stdout += chunk.toString()));
-      const message: RunMessage = { kind: 'run', testHooks };
-      sutProxy.send(message, (error: Error) => {
-        if (error) {
-          reject(error);
-          sutProxy.kill('SIGKILL');
-        }
-      });
-      sutProxy.on('message', (result: RunResult) => {
-        if (result.tests) {
-          resolve({ result, stdout });
-        } else {
-          reject(result);
-        }
-        sutProxy.kill('SIGKILL');
-      });
-    });
-  }
 });
diff --git a/packages/mocha-runner/test/integration/MochaTestFrameworkIntegrationTestWorker.ts b/packages/mocha-runner/test/integration/MochaTestFrameworkIntegrationTestWorker.ts
deleted file mode 100644
index 9afe472dcd..0000000000
--- a/packages/mocha-runner/test/integration/MochaTestFrameworkIntegrationTestWorker.ts
+++ /dev/null
@@ -1,65 +0,0 @@
-import * as path from 'path';
-
-import { commonTokens } from '@stryker-mutator/api/plugin';
-import { RunResult } from '@stryker-mutator/api/test_runner';
-import { testInjector } from '@stryker-mutator/test-helpers';
-
-import MochaTestRunner from '../../src/MochaTestRunner';
-
-export const AUTO_START_ARGUMENT = '2e164669-acf1-461c-9c05-2be139614de2';
-
-export type ChildMessage = RunMessage;
-
-export interface RunMessage {
-  kind: 'run';
-  testHooks?: string;
-}
-
-export default class MochaTestFrameworkIntegrationTestWorker {
-  public readonly sut: MochaTestRunner;
-
-  constructor() {
-    testInjector.options.mochaOptions = {
-      file: [],
-      ignore: [],
-      spec: [path.resolve(__dirname, '..', '..', 'testResources', 'sampleProject', 'MyMathSpec.js')]
-    };
-    this.sut = testInjector.injector
-      .provideValue(commonTokens.sandboxFileNames, [
-        path.resolve(__dirname, '..', '..', 'testResources', 'sampleProject', 'MyMath.js'),
-        path.resolve(__dirname, '..', '..', 'testResources', 'sampleProject', 'MyMathSpec.js')
-      ])
-      .injectClass(MochaTestRunner);
-
-    this.listenForParentProcess();
-    // try {
-    this.sut.init();
-    // } catch (err) {
-    //   this.sendError(err);
-    // }
-  }
-
-  public listenForParentProcess() {
-    process.on('message', (message: ChildMessage) => {
-      this.sut
-        .run({ testHooks: message.testHooks })
-        .then(result => this.send(result))
-        .catch(error => this.send(error));
-    });
-  }
-
-  public send(result: RunResult) {
-    if (process.send) {
-      process.send(result);
-    }
-  }
-  public sendError(error: Error) {
-    if (process.send) {
-      process.send({ name: error.name, message: error.message, stack: error.stack });
-    }
-  }
-}
-
-if (process.argv.includes(AUTO_START_ARGUMENT)) {
-  new MochaTestFrameworkIntegrationTestWorker();
-}
diff --git a/packages/mocha-runner/test/integration/QUnitSample.it.spec.ts b/packages/mocha-runner/test/integration/QUnitSample.it.spec.ts
index 5eecd5e5aa..d8ccaa82ba 100644
--- a/packages/mocha-runner/test/integration/QUnitSample.it.spec.ts
+++ b/packages/mocha-runner/test/integration/QUnitSample.it.spec.ts
@@ -5,7 +5,7 @@ import { RunStatus } from '@stryker-mutator/api/test_runner';
 import { testInjector } from '@stryker-mutator/test-helpers';
 import { expect } from 'chai';
 
-import MochaTestRunner from '../../src/MochaTestRunner';
+import { MochaTestRunner } from '../../src/MochaTestRunner';
 import { createMochaOptions } from '../helpers/factories';
 
 describe('QUnit sample', () => {
diff --git a/packages/mocha-runner/test/integration/SampleProject.it.spec.ts b/packages/mocha-runner/test/integration/SampleProject.it.spec.ts
index 5cb57d5f41..2b7f46c24e 100644
--- a/packages/mocha-runner/test/integration/SampleProject.it.spec.ts
+++ b/packages/mocha-runner/test/integration/SampleProject.it.spec.ts
@@ -6,7 +6,7 @@ import { testInjector } from '@stryker-mutator/test-helpers';
 import * as chai from 'chai';
 import * as chaiAsPromised from 'chai-as-promised';
 
-import MochaTestRunner from '../../src/MochaTestRunner';
+import { MochaTestRunner } from '../../src/MochaTestRunner';
 import { createMochaOptions } from '../helpers/factories';
 
 chai.use(chaiAsPromised);
diff --git a/packages/mocha-runner/test/unit/MochaTestRunner.spec.ts b/packages/mocha-runner/test/unit/MochaTestRunner.spec.ts
index e937e03c64..b2398e12bd 100644
--- a/packages/mocha-runner/test/unit/MochaTestRunner.spec.ts
+++ b/packages/mocha-runner/test/unit/MochaTestRunner.spec.ts
@@ -10,7 +10,7 @@ import * as Mocha from 'mocha';
 import sinon = require('sinon');
 import LibWrapper from '../../src/LibWrapper';
 import { MochaOptions } from '../../src/MochaOptions';
-import MochaTestRunner from '../../src/MochaTestRunner';
+import { MochaTestRunner } from '../../src/MochaTestRunner';
 import { StrykerMochaReporter } from '../../src/StrykerMochaReporter';
 import * as utils from '../../src/utils';
 
diff --git a/packages/mocha-runner/tsconfig.test.json b/packages/mocha-runner/tsconfig.test.json
index 099a53f9b5..d4b1083f05 100644
--- a/packages/mocha-runner/tsconfig.test.json
+++ b/packages/mocha-runner/tsconfig.test.json
@@ -17,6 +17,9 @@
     },
     {
       "path": "../test-helpers/tsconfig.src.json"
+    },
+    {
+      "path": "../core/tsconfig.src.json"
     }
   ]
-}
\ No newline at end of file
+}
diff --git a/packages/core/test/helpers/LoggingServer.ts b/packages/test-helpers/src/LoggingServer.ts
similarity index 78%
rename from packages/core/test/helpers/LoggingServer.ts
rename to packages/test-helpers/src/LoggingServer.ts
index 3edb1583d0..b0a8771266 100644
--- a/packages/core/test/helpers/LoggingServer.ts
+++ b/packages/test-helpers/src/LoggingServer.ts
@@ -4,13 +4,13 @@ import { parse } from 'flatted';
 import * as log4js from 'log4js';
 import { Observable, Subscriber } from 'rxjs';
 
-export default class LoggingServer {
+export class LoggingServer {
   private readonly server: net.Server;
   private subscriber: Subscriber<log4js.LoggingEvent> | undefined;
   public readonly event$: Observable<log4js.LoggingEvent>;
   private disposed = false;
 
-  constructor(public readonly port: number) {
+  constructor() {
     this.server = net.createServer(socket => {
       socket.on('data', data => {
         // Log4js also sends "__LOG4JS__" to signal an event end. Ignore those.
@@ -26,8 +26,6 @@ export default class LoggingServer {
         // This happens during integration tests, this is safe to ignore (log4js does that as well)
       });
     });
-    this.server.listen(this.port);
-
     this.event$ = new Observable<log4js.LoggingEvent>(subscriber => {
       this.subscriber = subscriber;
       this.server.on('close', () => {
@@ -36,6 +34,19 @@ export default class LoggingServer {
     });
   }
 
+  private alreadyListening = false;
+  public listen(): Promise<number> {
+    if (this.alreadyListening) {
+      throw new Error('Server already listening');
+    } else {
+      this.alreadyListening = true;
+      return new Promise(res => {
+        this.server.on('listening', () => res((this.server.address() as net.AddressInfo).port));
+        this.server.listen();
+      });
+    }
+  }
+
   public dispose(): Promise<void> {
     if (this.disposed) {
       return Promise.resolve();
diff --git a/packages/test-helpers/src/index.ts b/packages/test-helpers/src/index.ts
index c56bd55def..b922c3037a 100644
--- a/packages/test-helpers/src/index.ts
+++ b/packages/test-helpers/src/index.ts
@@ -2,3 +2,4 @@ import * as factory from './factory';
 
 export * from './TestInjector';
 export { factory };
+export * from './LoggingServer';