We're using [Jest](https://facebook.github.io/jest/) and [Enzyme](https://github.com/airbnb/enzyme) for our unit tests.

First of all, what we want with our unit tests is to ensure that our components behave the way we want. We're testing each component as a single unit. You should test your components isolated from the rest of the application (no redux involved for example)

Let's say we have a component like

class TheComponent extends React.Component {

foo = name => {

return `the ${name}`;

}

render() {

return(

<View>

{

this.props.isOpen &&

<Bar>Foo</Bar>

}

<Text>{this.props.name}</Text>

<Text>{this.foo()}</Text>

</View>

);

}

}

We would expect a couple of scenarios that test:

1. `the component should render the Bar component when isOpen is truthy`

2. `the component should not render the Bar component when isOpen is falsy`

3. `the method foo should return 'the NAME'`

As you can see, we didn't include a scenario that says something like `the component should render the name prop`, that's because testing that scenario will be like testing if React works. So please, avoid that kind of tests.

All the test files live under `/__tests__/`. In that folder you'll find everything you need to keep working on tests of create new ones. If you're adding a test for a component, you should find/create its file under `/__tests__/components/the-component.js`

A test file should look like:

import React from 'react';

import { shallow } from 'enzyme';

import { TheComponent, Bar } from 'components'; // this may change depending on WHAT you want to test. utils, actions, components, etc...

const defaultProps = {

isOpen: false,

name: 'foo'

};

describe('<TheComponent />', () => { // Usually, is the name of the component.

it('should render the Bar component when isOpen is truthy', () => {

const wrapper = shallow(

<TheComponent

{...defaultProps}

isOpen={false}

/>

);

expect(wrapper.find(Bar).length).toBe(1);

});

it('should not render the Bar component when isOpen is falsy', () => { ... });

it('should return 'the NAME' when foo received "name" as a param', () => { ... });

// ...add more tests accordingly

});

1. Try to always use `shallow` instead of `render`, it's faster and only renders your component 1 level deep (real unit tests)

2. Use the `defaultProps` object so you don't have to write all the props for each test

3. Try to not nest `describe` blocks unless it's absolutely necessary

4. Don't test unecessary stuff like we mentioned above

5. Every `it` must start with `should...` to keep things consistent

If you still have questions, don't hesitate to ask.