diff --git a/client/src/templates/Challenges/utils/worker-executor.test.js b/client/src/templates/Challenges/utils/worker-executor.test.js
new file mode 100644
index 0000000000..bfc5bb7a2b
--- /dev/null
+++ b/client/src/templates/Challenges/utils/worker-executor.test.js
@@ -0,0 +1,237 @@
+/* global expect, jest */
+
+import createWorker from './worker-executor';
+
+function mockWorker({ init, postMessage, terminate } = {}) {
+  global.Worker = jest.fn(function() {
+    setImmediate(
+      (init && init(this)) ||
+        (() =>
+          this.onmessage && this.onmessage({ data: { type: 'contentLoaded' } }))
+    );
+    this.onmessage = null;
+    this.postMessage =
+      postMessage ||
+      function(data) {
+        setImmediate(
+          () => this.onmessage && this.onmessage({ data: `${data} processed` })
+        );
+      };
+    this.terminate = terminate || (() => {});
+    return this;
+  });
+}
+
+afterEach(() => {
+  delete global.Worker;
+});
+
+it('Worker executor should successfully execute one task', async () => {
+  const terminateHandler = jest.fn();
+  mockWorker({ terminate: terminateHandler });
+  const testWorker = createWorker('test');
+  expect(testWorker).not.toBeUndefined();
+
+  const task = testWorker.execute('test');
+  expect(task).not.toBeUndefined();
+  expect(task.done).not.toBeUndefined();
+  const handler = jest.fn();
+  task.on('done', handler);
+  const errorHandler = jest.fn();
+  task.on('error', errorHandler);
+
+  await expect(task.done).resolves.toBe('test processed');
+
+  expect(handler).toBeCalledTimes(1);
+  expect(handler).toBeCalledWith('test processed');
+
+  expect(errorHandler).not.toBeCalled();
+  expect(terminateHandler).not.toBeCalled();
+
+  expect(global.Worker).toBeCalledTimes(1);
+  expect(global.Worker).toBeCalledWith('/js/test.js');
+});
+
+// eslint-disable-next-line max-len
+it('Worker executor should successfully execute two tasks in parallel', async () => {
+  const terminateHandler = jest.fn();
+  mockWorker({ terminate: terminateHandler });
+  const testWorker = createWorker('test');
+
+  const task1 = testWorker.execute('test1');
+  const handler1 = jest.fn();
+  task1.on('done', handler1);
+  const errorHandler1 = jest.fn();
+  task1.on('error', errorHandler1);
+
+  const task2 = testWorker.execute('test2');
+  const handler2 = jest.fn();
+  task2.on('done', handler2);
+  const errorHandler2 = jest.fn();
+  task2.on('error', errorHandler2);
+
+  await expect(Promise.all([task1.done, task2.done])).resolves.toEqual([
+    'test1 processed',
+    'test2 processed'
+  ]);
+
+  expect(handler1).toBeCalledTimes(1);
+  expect(handler1).toBeCalledWith('test1 processed');
+  expect(errorHandler1).not.toBeCalled();
+
+  expect(handler2).toBeCalledTimes(1);
+  expect(handler2).toBeCalledWith('test2 processed');
+  expect(errorHandler2).not.toBeCalled();
+  expect(terminateHandler).not.toBeCalled();
+
+  expect(global.Worker).toBeCalledTimes(2);
+});
+
+// eslint-disable-next-line max-len
+it('Worker executor should successfully execute 3 tasks in parallel and use two workers', async () => {
+  mockWorker();
+  const testWorker = createWorker('test');
+
+  const task1 = testWorker.execute('test1');
+  const task2 = testWorker.execute('test2');
+  const task3 = testWorker.execute('test3');
+  await expect(
+    Promise.all([task1.done, task2.done, task3.done])
+  ).resolves.toEqual(['test1 processed', 'test2 processed', 'test3 processed']);
+
+  expect(global.Worker).toBeCalledTimes(2);
+});
+
+// eslint-disable-next-line max-len
+it('Worker executor should successfully execute 3 tasks, use 3 workers and terminate each worker', async () => {
+  const terminateHandler = jest.fn();
+  mockWorker({ terminate: terminateHandler });
+  const testWorker = createWorker('test', { terminateWorker: true });
+
+  const task1 = testWorker.execute('test1');
+  const task2 = testWorker.execute('test2');
+  const task3 = testWorker.execute('test3');
+  await expect(
+    Promise.all([task1.done, task2.done, task3.done])
+  ).resolves.toEqual(['test1 processed', 'test2 processed', 'test3 processed']);
+
+  expect(terminateHandler).toBeCalledTimes(3);
+  expect(global.Worker).toBeCalledTimes(3);
+});
+
+// eslint-disable-next-line max-len
+it('Worker executor should successfully execute 3 tasks in parallel and use 3 workers', async () => {
+  mockWorker();
+  const testWorker = createWorker('test', { concurrency: 3 });
+
+  const task1 = testWorker.execute('test1');
+  const task2 = testWorker.execute('test2');
+  const task3 = testWorker.execute('test3');
+  await expect(
+    Promise.all([task1.done, task2.done, task3.done])
+  ).resolves.toEqual(['test1 processed', 'test2 processed', 'test3 processed']);
+
+  expect(global.Worker).toBeCalledTimes(3);
+});
+
+// eslint-disable-next-line max-len
+it('Worker executor should successfully execute 3 tasks and use 1 worker', async () => {
+  mockWorker();
+  const testWorker = createWorker('test', { concurrency: 1 });
+
+  const task1 = testWorker.execute('test1');
+  const task2 = testWorker.execute('test2');
+  const task3 = testWorker.execute('test3');
+  await expect(
+    Promise.all([task1.done, task2.done, task3.done])
+  ).resolves.toEqual(['test1 processed', 'test2 processed', 'test3 processed']);
+
+  expect(global.Worker).toBeCalledTimes(1);
+});
+
+it('Worker executor should reject task', async () => {
+  const error = { message: 'Error on init worker' };
+  mockWorker({
+    init: () => {
+      throw error;
+    }
+  });
+  const testWorker = createWorker('test');
+
+  const task = testWorker.execute('test');
+  const errorHandler = jest.fn();
+  task.on('error', errorHandler);
+  await expect(task.done).rejects.toBe(error.message);
+
+  expect(errorHandler).toBeCalledTimes(1);
+  expect(errorHandler).toBeCalledWith(error);
+});
+
+it('Worker executor should emit LOG events', async () => {
+  mockWorker({
+    postMessage: function(data) {
+      setImmediate(() => {
+        for (let i = 0; i < 3; i++) {
+          // eslint-disable-next-line no-unused-expressions
+          this.onmessage && this.onmessage({ data: { type: 'LOG', data: i } });
+        }
+        // eslint-disable-next-line no-unused-expressions
+        this.onmessage && this.onmessage({ data: `${data} processed` });
+        setImmediate(
+          () =>
+            this.onmessage && this.onmessage({ data: { type: 'LOG', data: 3 } })
+        );
+      });
+    }
+  });
+  const testWorker = createWorker('test');
+
+  const task = testWorker.execute('test');
+  const handler = jest.fn();
+  task.on('done', handler);
+  const errorHandler = jest.fn();
+  task.on('error', errorHandler);
+  const logHandler = jest.fn();
+  task.on('LOG', logHandler);
+
+  await expect(task.done).resolves.toBe('test processed');
+
+  expect(handler).toBeCalledTimes(1);
+  expect(handler).toBeCalledWith('test processed');
+  expect(errorHandler).not.toBeCalled();
+
+  expect(logHandler).toBeCalledTimes(3);
+  for (let i = 0; i < 3; i++) {
+    expect(logHandler.mock.calls[i][0]).toBe(i);
+  }
+});
+
+it('Worker executor should reject task on timeout', async () => {
+  const terminateHandler = jest.fn();
+  mockWorker({
+    postMessage: () => {},
+    terminate: terminateHandler
+  });
+  const testWorker = createWorker('test');
+
+  const task = testWorker.execute('test', 0);
+  const errorHandler = jest.fn();
+  task.on('error', errorHandler);
+  await expect(task.done).rejects.toBe('timeout');
+
+  expect(errorHandler).toBeCalledTimes(1);
+  expect(errorHandler.mock.calls[0][0]).toEqual({ message: 'timeout' });
+
+  expect(terminateHandler).toBeCalledTimes(1);
+});
+
+it('Worker executor should get worker from specified location', async () => {
+  mockWorker();
+  const testWorker = createWorker('test', { location: '/other/location/' });
+
+  const task = testWorker.execute('test');
+  await expect(task.done).resolves.toBe('test processed');
+
+  expect(global.Worker).toBeCalledTimes(1);
+  expect(global.Worker).toBeCalledWith('/other/location/test.js');
+});