react.dev/docs/09.4-test-utils.md

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

`React.addons.TestUtils` makes it easy to test React components in the testing framework of your choice (we use [Jasmine](http://pivotal.github.io/jasmine/) with [jsdom](https://github.com/tmpvar/jsdom)).

#### ReactComponent renderIntoDocument(ReactComponent instance)

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

#### boolean isComponentOfType(ReactComponent instance, function componentClass)

Returns true if `instance` is an instance of a React `componentClass`.

#### boolean isDOMComponent(ReactComponent instance)

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

#### boolean isCompositeComponent(ReactComponent instance)`

Returns true if `instance` is a composite component (created with `React.createClass()`)

#### boolean isCompositeComponentWithType(ReactComponent instance, function componentClass)

The combination of `isComponentOfType()` and `isCompositeComponent()`.

#### boolean isTextComponent(ReactComponent instance)

Returns true if `instance` is a plain text component.

#### array findAllInRenderedTree(ReactComponent tree, function 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.

#### array scryRenderedDOMComponentsWithClass(ReactCompoennt tree, string className)

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

#### ReactComponent findRenderedDOMComponentWithClass(ReactComponent tree, string 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.

#### array scryRenderedDOMComponentsWithTag(ReactComponent tree, string tagName)

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

#### ReactComponent findRenderedDOMComponentWithTag(ReactComponent tree, string 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.

#### array scryRenderedComponentsWithType(ReactComponent tree, function componentClass)

Finds all instances of components with type equal to `componentClass`.

#### ReactComponent findRenderedComponentWithType(ReactComponent tree, function 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.

#### object mockComponent(function componentClass, string? tagName)

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.

#### Simulate.{eventName}({ReactComponent|DOMElement} element, object nativeEventData)

Simulate an event dispatch on a React component instance or browser DOM node with optional `nativeEventData` event data. **This is possibly the single most useful utility in `ReactTestUtils`.**

> Note:
>
> This helper is used to simulate browser events, so synthetic React events like `change` are not available. If you want to test `change`, simulate the underlying `input` browser event.

Example usage: `React.addons.TestUtils.Simulate.click(myComponent)`

`Simulate` has a method for every event that React understands.