---
id: test-utils
title: Test Utilities
permalink: docs/test-utils.html
layout: docs
category: Reference
---

**Importing**

```javascript
import ReactTestUtils from 'react-dom/test-utils'; // ES6
var ReactTestUtils = require('react-dom/test-utils'); // ES5 with npm
```

## Overview

`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/en/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/)
>
> Alternatively, there is another testing utility called react-testing-library designed to enable and encourage writing tests that use your components as the end users use them. It also works with any test runner: [https://git.io/react-testing-library](https://git.io/react-testing-library)

 - [`Simulate`](#simulate)
 - [`renderIntoDocument()`](#renderintodocument)
 - [`mockComponent()`](#mockcomponent)
 - [`isElement()`](#iselement)
 - [`isElementOfType()`](#iselementoftype)
 - [`isDOMComponent()`](#isdomcomponent)
 - [`isCompositeComponent()`](#iscompositecomponent)
 - [`isCompositeComponentWithType()`](#iscompositecomponentwithtype)
 - [`findAllInRenderedTree()`](#findallinrenderedtree)
 - [`scryRenderedDOMComponentsWithClass()`](#scryrendereddomcomponentswithclass)
 - [`findRenderedDOMComponentWithClass()`](#findrendereddomcomponentwithclass)
 - [`scryRenderedDOMComponentsWithTag()`](#scryrendereddomcomponentswithtag)
 - [`findRenderedDOMComponentWithTag()`](#findrendereddomcomponentwithtag)
 - [`scryRenderedComponentsWithType()`](#scryrenderedcomponentswithtype)
 - [`findRenderedComponentWithType()`](#findrenderedcomponentwithtype)

## Reference

## Shallow Rendering

When writing unit tests for React, shallow rendering can be helpful. Shallow rendering lets you render a component "one level deep" and assert facts about what its render method returns, without worrying about the behavior of child components, which are not instantiated or rendered. This does not require a DOM.

> Note:
>
> The shallow renderer has moved to `react-test-renderer/shallow`.<br>
> [Learn more about shallow rendering on its reference page.](/docs/shallow-renderer.html)

## Other Utilities

### `Simulate`

```javascript
Simulate.{eventName}(
  element,
  [eventData]
)
```

Simulate an event dispatch on a DOM node with optional `eventData` event data.

`Simulate` has a method for [every event that React understands](/docs/events.html#supported-events).

**Clicking an element**

```javascript
// <button ref={(node) => this.button = node}>...</button>
const node = this.button;
ReactTestUtils.Simulate.click(node);
```

**Changing the value of an input field and then pressing ENTER.**

```javascript
// <input ref={(node) => this.textInput = node} />
const node = this.textInput;
node.value = 'giraffe';
ReactTestUtils.Simulate.change(node);
ReactTestUtils.Simulate.keyDown(node, {key: "Enter", keyCode: 13, which: 13});
```

> Note
>
> 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.

* * *

### `renderIntoDocument()`

```javascript
renderIntoDocument(element)
```

Render a React element into a detached DOM node in the document. **This function requires a DOM.**

> Note:
>
> 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.

> Note:
>
> `mockComponent()` is a legacy API. We recommend using [shallow rendering](/docs/test-utils.html#shallow-rendering) or [`jest.mock()`](https://facebook.github.io/jest/docs/en/tutorial-react-native.html#mock-native-modules-using-jestmock) instead.

* * *

### `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.

* * *