Angular 2 Unit Tests: Cannot find name ‘describe’


I'm following this tutorial from

As they said, I've created hero.spec.ts file to create unit tests:

import { Hero } from './hero';
describe('Hero', () => {
  it('has name', () => {
    let hero: Hero = {id: 1, name: 'Super Cat'};
    expect('Super Cat');
  it('has id', () => {
    let hero: Hero = {id: 1, name: 'Super Cat'};

Unit Tests work like a charm. The problem is: I see some errors, which are mentioned in tutorial:

Our editor and the compiler may complain that they don’t know what it
and expect are because they lack the typing files that describe
Jasmine. We can ignore those annoying complaints for now as they are

And they indeed ignored it. Even though those errors are harmless, it doesn't look good in my output console when I receive bunch of them.

Example of what I get:

Cannot find name 'describe'.

Cannot find name 'it'.

Cannot find name 'expect'.

What can I do to fix it?

Best Solution

I hope you've installed -

npm install --save-dev @types/jasmine

Then put following import at the top of the hero.spec.ts file -

import 'jasmine';

It should solve the problem.