`ReactTestUtils` makes it easy to test React components in the testing framework of your choice. At Facebook we use [Jest](https://facebook.github.io/jest/) for painless JavaScript testing. Learn how to get started with Jest through the Jest website's [React Tutorial](http://facebook.github.io/jest/docs/tutorial-react.html#content).
> Note:
>
> Airbnb has released a testing utility called Enzyme, which makes it easy to assert, manipulate, and traverse your React Components' output. If you're deciding on a unit testing utility to use together with Jest, or any other test runner, it's worth checking out: [http://airbnb.io/enzyme/](http://airbnb.io/enzyme/)
> You will have to provide any event property that you're using in your component (e.g. keyCode, which, etc...) as React is not creating any of these for you.
> You will need to have `window`, `window.document` and `window.document.createElement` globally available **before** you import `React`. Otherwise React will think it can't access the DOM and methods like `setState` won't work.
* * *
### `mockComponent()`
```javascript
mockComponent(
componentClass,
[mockTagName]
)
```
Pass a mocked component module to this method to augment it with useful methods that allow it to be used as a dummy React component. Instead of rendering as usual, the component will become a simple `<div>` (or other tag if `mockTagName` is provided) containing any provided children.
* * *
### `isElement()`
```javascript
isElement(element)
```
Returns `true` if `element` is any React element.
* * *
### `isElementOfType()`
```javascript
isElementOfType(
element,
componentClass
)
```
Returns `true` if `element` is a React element whose type is of a React `componentClass`.
* * *
### `isDOMComponent()`
```javascript
isDOMComponent(instance)
```
Returns `true` if `instance` is a DOM component (such as a `<div>` or `<span>`).
* * *
### `isCompositeComponent()`
```javascript
isCompositeComponent(instance)
```
Returns `true` if `instance` is a user-defined component, such as a class or a function.
* * *
### `isCompositeComponentWithType()`
```javascript
isCompositeComponentWithType(
instance,
componentClass
)
```
Returns `true` if `instance` is a component whose type is of a React `componentClass`.
* * *
### `findAllInRenderedTree()`
```javascript
findAllInRenderedTree(
tree,
test
)
```
Traverse all components in `tree` and accumulate all components where `test(component)` is `true`. This is not that useful on its own, but it's used as a primitive for other test utils.
* * *
### `scryRenderedDOMComponentsWithClass()`
```javascript
scryRenderedDOMComponentsWithClass(
tree,
className
)
```
Finds all DOM elements of components in the rendered tree that are DOM components with the class name matching `className`.
* * *
### `findRenderedDOMComponentWithClass()`
```javascript
findRenderedDOMComponentWithClass(
tree,
className
)
```
Like [`scryRenderedDOMComponentsWithClass()`](#scryrendereddomcomponentswithclass) but expects there to be one result, and returns that one result, or throws exception if there is any other number of matches besides one.
* * *
### `scryRenderedDOMComponentsWithTag()`
```javascript
scryRenderedDOMComponentsWithTag(
tree,
tagName
)
```
Finds all DOM elements of components in the rendered tree that are DOM components with the tag name matching `tagName`.
* * *
### `findRenderedDOMComponentWithTag()`
```javascript
findRenderedDOMComponentWithTag(
tree,
tagName
)
```
Like [`scryRenderedDOMComponentsWithTag()`](#scryrendereddomcomponentswithtag) but expects there to be one result, and returns that one result, or throws exception if there is any other number of matches besides one.
* * *
### `scryRenderedComponentsWithType()`
```javascript
scryRenderedComponentsWithType(
tree,
componentClass
)
```
Finds all instances of components with type equal to `componentClass`.
* * *
### `findRenderedComponentWithType()`
```javascript
findRenderedComponentWithType(
tree,
componentClass
)
```
Same as [`scryRenderedComponentsWithType()`](#scryrenderedcomponentswithtype) but expects there to be one result and returns that one result, or throws exception if there is any other number of matches besides one.
* * *
## Shallow Rendering
### `createRenderer()`
```javascript
createRenderer()
```
Call this in your tests to create a [shallow renderer](#shallow-rendering).
* * *
### `shallowRenderer.render()`
```javascript
shallowRenderer.render(
element
)
```
Similar to [`ReactDOM.render`](/react/docs/react-dom.html#render) but it doesn't require DOM and only renders a single level deep. See [Shallow Rendering](#shallow-rendering).
* * *
### `shallowRenderer.getRenderOutput()`
```javascript
shallowRenderer.getRenderOutput()
```
After [`shallowRenderer.render()`](#shallowrenderer.render) has been called, returns shallowly rendered output.
