Question: How do I check if a component is not present, i.e. that a specific component has not been rendered?

Answer: 
You can use enzymes [`contains`](http://airbnb.io/enzyme/docs/api/ShallowWrapper/contains.html) to check if the component was rendered:

```
expect(component.contains(<ComponentName />)).toBe(false)

```
We use Jest and Enzyme, and I've found the only good test is to import the sub-component and test this way:

```
expect(component.find(SubComponent).length).toEqual(0); // or (1) for exists, obvs

```

I tried all the other answers and none worked reliably.