Test Utilities

Importing

import ReactTestUtils from 'react-addons-test-utils' // ES6
var ReactTestUtils = require('react-addons-test-utils') // ES5 with npm
var ReactTestUtils = React.addons.TestUtils; // ES5 with react-with-addons.js

Overview

ReactTestUtils makes it easy to test React components in the testing framework of your choice. At Facebook we use Jest for painless JavaScript testing. Learn how to get started with Jest through the Jest website's React Tutorial.

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/

• Simulate
• renderIntoDocument()
• mockComponent()
• isElement()
• isElementOfType()
• isDOMComponent()
• isCompositeComponent()
• isCompositeComponentWithType()
• findAllInRenderedTree()
• scryRenderedDOMComponentsWithClass()
• findRenderedDOMComponentWithClass()
• scryRenderedDOMComponentsWithTag()
• findRenderedDOMComponentWithTag()
• scryRenderedComponentsWithType()
• findRenderedComponentWithType()

Shallow Rendering

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.

• createRenderer()
• shallowRenderer.render()
• shallowRenderer.getRenderOutput()

Call createRenderer() in your tests to create a shallow renderer. You can think of this as a "place" to render the component you're testing, and from which you can extract the component's output.

shallowRenderer.render() is similar to ReactDOM.render() but it doesn't require DOM and only renders a single level deep. This means you can test components isolated from how their children are implemented.

After shallowRenderer.render() has been called, you can use shallowRenderer.getRenderOutput() to get the shallowly rendered output.

You can then begin to assert facts about the output. For example, if you have the following component:

function MyComponent() {
  return (
    <div>
      <span className="heading">Title</span>
      <Subcomponent foo="bar" />
    </div>
  );
}

Then you can assert:

const renderer = ReactTestUtils.createRenderer();
renderer.render(<MyComponent />);
const result = renderer.getRenderOutput();

expect(result.type).toBe('div');
expect(result.props.children).toEqual([
  <span className="heading">Title</span>,
  <Subcomponent foo="bar" />
]);

Shallow testing currently has some limitations, namely not supporting refs.

We also recommend checking out Enzyme's Shallow Rendering API. It provides a nicer higher-level API over the same functionality.

Reference

Simulate

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.

Clicking an element

// <button ref="button">...</button>
const node = this.refs.button;
ReactTestUtils.Simulate.click(node);

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

// <input ref="input" />
const node = this.refs.input;
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()

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()

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()

isElement(element)

Returns true if element is any React element.

isElementOfType()

isElementOfType(
  element,
  componentClass
)

Returns true if element is a React element whose type is of a React componentClass.

isDOMComponent()

isDOMComponent(instance)

Returns true if instance is a DOM component (such as a <div> or <span>).

isCompositeComponent()

isCompositeComponent(instance)

Returns true if instance is a user-defined component, such as a class or a function.

isCompositeComponentWithType()

isCompositeComponentWithType(
  instance,
  componentClass
)

Returns true if instance is a component whose type is of a React componentClass.

findAllInRenderedTree()

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()

scryRenderedDOMComponentsWithClass(
  tree,
  className
)

Finds all DOM elements of components in the rendered tree that are DOM components with the class name matching className.

findRenderedDOMComponentWithClass()

findRenderedDOMComponentWithClass(
  tree,
  className
)

Like 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()

scryRenderedDOMComponentsWithTag(
  tree,
  tagName
)

Finds all DOM elements of components in the rendered tree that are DOM components with the tag name matching tagName.

findRenderedDOMComponentWithTag()

findRenderedDOMComponentWithTag(
  tree,
  tagName
)

Like 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()

scryRenderedComponentsWithType(
  tree,
  componentClass
)

Finds all instances of components with type equal to componentClass.

findRenderedComponentWithType()

findRenderedComponentWithType(
  tree,
  componentClass
)

Same as 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()

createRenderer()

Call this in your tests to create a shallow renderer.

shallowRenderer.render()

shallowRenderer.render(
  element
)

Similar to ReactDOM.render but it doesn't require DOM and only renders a single level deep. See Shallow Rendering.

shallowRenderer.getRenderOutput()

shallowRenderer.getRenderOutput()

After shallowRenderer.render() has been called, returns shallowly rendered output.