chai-jsdom

chai-jsdom

A plugin for Chai that builds on top of @testing-library/jest-dom to provide its same checkers but for Chai.

The following docs are adjusted from @testing-library/jest-dom's README.

Installation

This module is distributed via npm which is bundled with node and should be installed as one of your project's devDependencies:

npm install --save-dev chai-jsdom

or

for installation with yarn package manager.

yarn add --dev chai-jsdom

Usage

Import chai-jsdom and use it with chai's use:

// In your own jest-setup.js (or any other name)
import { use } from 'chai';
import chaiJSDOM from 'chai-jsdom'

use(chaiJSDOM);

Custom matchers

chai-jsdom can work with any library or framework that returns DOM elements from queries. The custom matcher examples below are written using matchers from @testing-library's suite of libraries (e.g. getByTestId, queryByTestId, getByText, etc.)

.disabled

This allows you to check whether an element is disabled from the user's perspective. According to the specification, the following elements can be disabled: button, input, select, textarea, optgroup, option, fieldset, and custom elements.

This custom matcher considers an element as disabled if the element is among the types of elements that can be disabled (listed above), and the disabled attribute is present. It will also consider the element as disabled if it's inside a parent form element that supports being disabled and has the disabled attribute present.

Examples

<button data-testid="button" type="submit" disabled>submit</button>
<fieldset disabled><input type="text" data-testid="input" /></fieldset>
<a href="..." disabled>link</a>

expect(getByTestId('button')).to.be.disabled
expect(getByTestId('input')).to.be.disabled
expect(getByText('link')).not.to.be.disabled

This custom matcher does not take into account the presence or absence of the aria-disabled attribute. For more on why this is the case, check #144.

---

.enabled

This allows you to check whether an element is not disabled from the user's perspective.

It works like not.disabled. Use this matcher to avoid double negation in your tests.

This custom matcher does not take into account the presence or absence of the aria-disabled attribute. For more on why this is the case, check #144.

---

.empty

This allows you to assert whether an element has no visible content for the user. It ignores comments but will fail if the element contains white-space.

It extends Chai's empty when used with an HTML element.

Examples

<span data-testid="not-empty"><span data-testid="empty"></span></span>
<span data-testid="with-whitespace"> </span>
<span data-testid="with-comment"><!-- comment --></span>

expect(getByTestId('empty')).to.be.empty
expect(getByTestId('not-empty')).not.to.be.empty
expect(getByTestId('with-whitespace')).not.to.be.empty

---

.document

This allows you to assert whether an element is present in the document or not.

Examples

<span data-testid="html-element"><span>Html Element</span></span>
<svg data-testid="svg-element"></svg>

expect(
  getByTestId(document.documentElement, 'html-element'),
).to.be.in.document
expect(getByTestId(document.documentElement, 'svg-element')).to.be.in.document
expect(
  queryByTestId(document.documentElement, 'does-not-exist'),
).not.to.be.in.document

Note: This matcher does not find detached elements. The element must be added to the document to be found by toBeInTheDocument. If you desire to search in a detached element please use: .contain

---

.invalid

This allows you to check if an element, is currently invalid.

An element is invalid if it has an aria-invalid attribute with no value or a value of "true", or if the result of checkValidity() is false.

Examples

<input data-testid="no-aria-invalid" />
<input data-testid="aria-invalid" aria-invalid />
<input data-testid="aria-invalid-value" aria-invalid="true" />
<input data-testid="aria-invalid-false" aria-invalid="false" />

<form data-testid="valid-form">
  <input />
</form>

<form data-testid="invalid-form">
  <input required />
</form>

expect(getByTestId('no-aria-invalid')).not.to.be.invalid
expect(getByTestId('aria-invalid')).to.be.invalid
expect(getByTestId('aria-invalid-value')).to.be.invalid
expect(getByTestId('aria-invalid-false')).not.to.be.invalid

expect(getByTestId('valid-form')).not.to.be.invalid
expect(getByTestId('invalid-form')).to.be.invalid

---

.required

This allows you to check if a form element is currently required.

An element is required if it is having a required or aria-required="true" attribute.

Examples

<input data-testid="required-input" required />
<input data-testid="aria-required-input" aria-required="true" />
<input data-testid="conflicted-input" required aria-required="false" />
<input data-testid="aria-not-required-input" aria-required="false" />
<input data-testid="optional-input" />
<input data-testid="unsupported-type" type="image" required />
<select data-testid="select" required></select>
<textarea data-testid="textarea" required></textarea>
<div data-testid="supported-role" role="tree" required></div>
<div data-testid="supported-role-aria" role="tree" aria-required="true"></div>

expect(getByTestId('required-input')).to.be.required
expect(getByTestId('aria-required-input')).to.be.required
expect(getByTestId('conflicted-input')).to.be.required
expect(getByTestId('aria-not-required-input')).not.to.be.required
expect(getByTestId('optional-input')).not.to.be.required
expect(getByTestId('unsupported-type')).not.to.be.required
expect(getByTestId('select')).to.be.required
expect(getByTestId('textarea')).to.be.required
expect(getByTestId('supported-role')).not.to.be.required
expect(getByTestId('supported-role-aria')).to.be.required

---

.valid

This allows you to check if the value of an element, is currently valid.

An element is valid if it has no aria-invalid attributes or an attribute value of "false". The result of checkValidity() must also be true if it's a form element.

Examples

<input data-testid="no-aria-invalid" />
<input data-testid="aria-invalid" aria-invalid />
<input data-testid="aria-invalid-value" aria-invalid="true" />
<input data-testid="aria-invalid-false" aria-invalid="false" />

<form data-testid="valid-form">
  <input />
</form>

<form data-testid="invalid-form">
  <input required />
</form>

expect(getByTestId('no-aria-invalid')).to.be.valid
expect(getByTestId('aria-invalid')).not.to.be.valid
expect(getByTestId('aria-invalid-value')).not.to.be.valid
expect(getByTestId('aria-invalid-false')).to.be.valid

expect(getByTestId('valid-form')).to.be.valid
expect(getByTestId('invalid-form')).not.to.be.valid

---

.visible

This allows you to check if an element is currently visible to the user.

An element is visible if all the following conditions are met:

• it is present in the document
• it does not have its css property display set to none
• it does not have its css property visibility set to either hidden or collapse
• it does not have its css property opacity set to 0
• its parent element is also visible (and so on up to the top of the DOM tree)
• it does not have the hidden attribute
• if <details /> it has the open attribute

Examples

<div data-testid="zero-opacity" style="opacity: 0">Zero Opacity Example</div>
<div data-testid="visibility-hidden" style="visibility: hidden">
  Visibility Hidden Example
</div>
<div data-testid="display-none" style="display: none">Display None Example</div>
<div style="opacity: 0">
  <span data-testid="hidden-parent">Hidden Parent Example</span>
</div>
<div data-testid="visible">Visible Example</div>
<div data-testid="hidden-attribute" hidden>Hidden Attribute Example</div>

expect(getByText('Zero Opacity Example')).not.to.be.visible
expect(getByText('Visibility Hidden Example')).not.to.be.visible
expect(getByText('Display None Example')).not.to.be.visible
expect(getByText('Hidden Parent Example')).not.to.be.visible
expect(getByText('Visible Example')).to.be.visible
expect(getByText('Hidden Attribute Example')).not.to.be.visible

---

.contain

This allows you to assert whether an element contains another element as a descendant or not.

This extends Chai's contain. You can use contains, contain and contains as aliases.

Examples

<span data-testid="ancestor"><span data-testid="descendant"></span></span>

const ancestor = getByTestId('ancestor')
const descendant = getByTestId('descendant')
const nonExistantElement = getByTestId('does-not-exist')

expect(ancestor).to.contain(descendant)
expect(descendant).not.to.contain(ancestor)
expect(ancestor).not.to.contain(nonExistantElement)

---

.html

Assert whether a string representing a HTML element is contained in another element. The string should contain valid html, and not any incomplete html.

Examples

<span data-testid="parent"><span data-testid="child"></span></span>

// These are valid uses
expect(getByTestId('parent')).to.contain.html('<span data-testid="child"></span>')
expect(getByTestId('parent')).to.contain.html('<span data-testid="child" />')
expect(getByTestId('parent')).not.to.contain.html('<br />')

// These won't work
expect(getByTestId('parent')).to.contain.html('data-testid="child"')
expect(getByTestId('parent')).to.contain.html('data-testid')
expect(getByTestId('parent')).to.contain.html('</span>')

Chances are you probably do not need to use this matcher. We encourage testing from the perspective of how the user perceives the app in a browser. That's why testing against a specific DOM structure is not advised.

It could be useful in situations where the code being tested renders html that was obtained from an external source, and you want to validate that that html code was used as intended.

It should not be used to check DOM structure that you control. Please use .contain instead.

---

.description

toHaveAccessibleDescription(expectedAccessibleDescription?: string | RegExp)

This allows you to assert that an element has the expected accessible description.

Every assertion done after .description is done on top of the accessible description of the element tested.

Examples

<a
  data-testid="link"
  href="/"
  aria-label="Home page"
  title="A link to start over"
  >Start</a
>
<a data-testid="extra-link" href="/about" aria-label="About page">About</a>
<img src="avatar.jpg" data-testid="avatar" alt="User profile pic" />
<img
  src="logo.jpg"
  data-testid="logo"
  alt="Company logo"
  aria-describedby="t1"
/>
<span id="t1" role="presentation">The logo of Our Company</span>

expect(getByTestId('link')).to.have.a.description
expect(getByTestId('link')).to.have.a.description.that.equals('A link to start over')
expect(getByTestId('link')).to.have.a.description.that.does.not.equal('Home page')
expect(getByTestId('extra-link')).not.to.have.a.description
expect(getByTestId('avatar')).not.to.have.a.description
expect(getByTestId('logo')).to.have.a.description.that.does.not.equal('Company logo')
expect(getByTestId('logo')).to.have.a.description.that.equals(
  'The logo of Our Company',
)
expect(getByTestId('logo')).to.have.a.description.that.contains(
  'Our Company',
)

---

.accessibleName

toHaveAccessibleName(expectedAccessibleName?: string | RegExp)

This allows you to assert that an element has the expected accessible name. It is useful, for instance, to assert that form elements and buttons are properly labelled.

Every assertion done after .description is done on top of the accessible name of the element tested.

Examples

<img data-testid="img-alt" src="" alt="Test alt" />
<img data-testid="img-empty-alt" src="" alt="" />
<svg data-testid="svg-title"><title>Test title</title></svg>
<button data-testid="button-img-alt"><img src="" alt="Test" /></button>
<p><img data-testid="img-paragraph" src="" alt="" /> Test content</p>
<button data-testid="svg-button"><svg><title>Test</title></svg></p>
<div><svg data-testid="svg-without-title"></svg></div>
<input data-testid="input-title" title="test" />

expect(getByTestId('img-alt')).toHaveAccessibleName('Test alt')
expect(getByTestId('img-empty-alt')).not.toHaveAccessibleName()
expect(getByTestId('svg-title')).toHaveAccessibleName('Test title')
expect(getByTestId('button-img-alt')).toHaveAccessibleName()
expect(getByTestId('img-paragraph')).not.toHaveAccessibleName()
expect(getByTestId('svg-button')).toHaveAccessibleName()
expect(getByTestId('svg-without-title')).not.toHaveAccessibleName()
expect(getByTestId('input-title')).toHaveAccessibleName()

---

toHaveAttribute

toHaveAttribute(attr: string, value?: any)

This allows you to check whether the given element has an attribute or not. You can also optionally check that the attribute has a specific expected value or partial match using expect.stringContaining/expect.stringMatching

Examples

<button data-testid="ok-button" type="submit" disabled>ok</button>

const button = getByTestId('ok-button')

expect(button).toHaveAttribute('disabled')
expect(button).toHaveAttribute('type', 'submit')
expect(button).not.toHaveAttribute('type', 'button')

expect(button).toHaveAttribute('type', expect.stringContaining('sub'))
expect(button).toHaveAttribute('type', expect.not.stringContaining('but'))

---

.class

toHaveClass(...classNames: string[], options?: {exact: boolean})

This allows you to check whether the given element has certain classes within its class attribute.

Every assertion done after .class is done on the class of the element being tested. include and members get extended to support a string with multiple classes.

Examples

<button data-testid="delete-button" class="btn extra btn-danger">
  Delete item
</button>
<button data-testid="no-classes">No Classes</button>

const deleteButton = getByTestId('delete-button')
const noClasses = getByTestId('no-classes')

expect(deleteButton).to.have.class.that.contains('extra')
expect(deleteButton).to.have.class.that.contains('btn-danger btn')
expect(deleteButton).to.have.class.that.contains.members(['btn-danger', 'btn'])
expect(deleteButton).to.have.class.that.does.not.contain('btn-link')

expect(deleteButton).to.have.class.that.equals('btn-danger extra btn') // to check if the element has EXACTLY a set of classes
expect(deleteButton).to.have.class.that.does.not.equal('btn-danger extra') // if it has more than expected it is going to fail

expect(noClasses).not.to.have.class

---

.focused

This allows you to assert whether an element has focus or not.

You can use .focus as an alias.

Examples

<div><input type="text" data-testid="element-to-focus" /></div>

const input = getByTestId('element-to-focus')

input.focus()
expect(input).to.have.focus()

input.blur()
expect(input).not.to.be.focused()

---

.formValues

This allows you to check if a form or fieldset contains form controls for each given name, and having the specified value.

It is important to stress that this matcher can only be invoked on a form or a fieldset element.

This allows it to take advantage of the .elements property in form and fieldset to reliably fetch all form controls within them.

This also avoids the possibility that users provide a container that contains more than one form, thereby intermixing form controls that are not related, and could even conflict with one another.

This matcher abstracts away the particularities with which a form control value is obtained depending on the type of form control. For instance, <input> elements have a value attribute, but <select> elements do not. Here's a list of all cases covered:

• <input type="number"> elements return the value as a number, instead of a string.
• <input type="checkbox"> elements:
  • if there's a single one with the given name attribute, it is treated as a boolean, returning true if the checkbox is checked, false if unchecked.
  • if there's more than one checkbox with the same name attribute, they are all treated collectively as a single form control, which returns the value as an array containing all the values of the selected checkboxes in the collection.
• <input type="radio"> elements are all grouped by the name attribute, and such a group treated as a single form control. This form control returns the value as a string corresponding to the value attribute of the selected radio button within the group.
• <input type="text"> elements return the value as a string. This also applies to <input> elements having any other possible type attribute that's not explicitly covered in different rules above (e.g. search, email, date, password, hidden, etc.)
• <select> elements without the multiple attribute return the value as a string corresponding to the value attribute of the selected option, or undefined if there's no selected option.
• <select multiple> elements return the value as an array containing all the values of the selected options.
• <textarea> elements return their value as a string. The value corresponds to their node content.

The above rules make it easy, for instance, to switch from using a single select control to using a group of radio buttons. Or to switch from a multi select control, to using a group of checkboxes. The resulting set of form values used by this matcher to compare against would be the same.

Examples

<form data-testid="login-form">
  <input type="text" name="username" value="jane.doe" />
  <input type="password" name="password" value="12345678" />
  <input type="checkbox" name="rememberMe" checked />
  <button type="submit">Sign in</button>
</form>

expect(getByTestId('login-form')).to.have.formValues({
  username: 'jane.doe',
  rememberMe: true,
})

.style

This allows you to check if a certain element has some specific css properties with specific values applied. It matches only if the element has all the expected properties applied, not just some of them.

Examples

<button
  data-testid="delete-button"
  style="display: none; background-color: red"
>
  Delete item
</button>

const button = getByTestId('delete-button')

expect(button).to.have.style('display: none')
expect(button).to.have.style({display: 'none'})
expect(button).to.have.style(`
  background-color: red;
  display: none;
`)
expect(button).to.have.style({
  backgroundColor: 'red',
  display: 'none',
})
expect(button).not.to.have.style(`
  background-color: blue;
  display: none;
`)
expect(button).not.to.have.style({
  backgroundColor: 'blue',
  display: 'none',
})

This also works with rules that are applied to the element via a class name for which some rules are defined in a stylesheet currently active in the document. The usual rules of css precedence apply.

---

.text

This allows you to check whether the given node has a text content or not. This supports elements, but also text nodes and fragments.

Every assertion done after this will be done on the textContent of the element being tested.

Examples

<span data-testid="text-content">Text Content</span>

const element = getByTestId('text-content')

expect(element).to.have.text.that.contains('Content')
expect(element).to.have.text.that.matches(/^Text Content$/) // to match the whole content
expect(element).to.have.text.that.matches(/content$/i) // to use case-insensitive match
expect(element).to.have.text.that.does.not.contain('content')

---

.value

This allows you to check whether the given form element has the specified value. It accepts <input>, <select> and <textarea> elements with the exception of <input type="checkbox"> and <input type="radio">, which can be meaningfully matched only using .checked or .formValues.

Every assertion done after this will be done on the value of the element being tested.

For all other form elements, the value is matched using the same algorithm as in .formValues does.

Examples

<input type="text" value="text" data-testid="input-text" />
<input type="number" value="5" data-testid="input-number" />
<input type="text" data-testid="input-empty" />
<select multiple data-testid="select-number">
  <option value="first">First Value</option>
  <option value="second" selected>Second Value</option>
  <option value="third" selected>Third Value</option>
</select>

Using DOM Testing Library

const textInput = getByTestId('input-text')
const numberInput = getByTestId('input-number')
const emptyInput = getByTestId('input-empty')
const selectInput = getByTestId('select-number')

expect(textInput).to.have.value.that.equals('text')
expect(numberInput).to.have.value.that.equals(5)
expect(emptyInput).not.to.have.value
expect(selectInput).to.have.value.that.has.members(['second', 'third'])

---

.display

This allows you to check whether the given form element has the specified displayed value (the one the end user will see) when used before .value. It accepts <input>, <select> and <textarea> elements with the exception of <input type="checkbox"> and <input type="radio">, which can be meaningfully matched only using .checked or .formValues.

Examples

<label for="input-example">First name</label>
<input type="text" id="input-example" value="Luca" />

<label for="textarea-example">Description</label>
<textarea id="textarea-example">An example description here.</textarea>

<label for="single-select-example">Fruit</label>
<select id="single-select-example">
  <option value="">Select a fruit...</option>
  <option value="banana">Banana</option>
  <option value="ananas">Ananas</option>
  <option value="avocado">Avocado</option>
</select>

<label for="multiple-select-example">Fruits</label>
<select id="multiple-select-example" multiple>
  <option value="">Select a fruit...</option>
  <option value="banana" selected>Banana</option>
  <option value="ananas">Ananas</option>
  <option value="avocado" selected>Avocado</option>
</select>

Using DOM Testing Library

const input = screen.getByLabelText('First name')
const textarea = screen.getByLabelText('Description')
const selectSingle = screen.getByLabelText('Fruit')
const selectMultiple = screen.getByLabelText('Fruits')

expect(input).to.have.display.value.that.equals('Luca')
expect(input).to.have.display.value.that.matches(/Luc/)
expect(textarea).to.have.display.value.that.equals('An example description here.')
expect(textarea).to.have.display.value.that.matches(/example/)
expect(selectSingle).to.have.display.value.that.equals('Select a fruit...')
expect(selectSingle).to.have.display.value.that.matches(/Select/)
expect(selectMultiple).to.have.display.value.that.matches(/Avocado/)
    .and.contains('Banana')

---

.checked

This allows you to check whether the given element is checked. It accepts an input of type checkbox or radio and elements with a role of checkbox, radio or switch with a valid aria-checked attribute of "true" or "false".

Examples

<input type="checkbox" checked data-testid="input-checkbox-checked" />
<input type="checkbox" data-testid="input-checkbox-unchecked" />
<div role="checkbox" aria-checked="true" data-testid="aria-checkbox-checked" />
<div
  role="checkbox"
  aria-checked="false"
  data-testid="aria-checkbox-unchecked"
/>

<input type="radio" checked value="foo" data-testid="input-radio-checked" />
<input type="radio" value="foo" data-testid="input-radio-unchecked" />
<div role="radio" aria-checked="true" data-testid="aria-radio-checked" />
<div role="radio" aria-checked="false" data-testid="aria-radio-unchecked" />
<div role="switch" aria-checked="true" data-testid="aria-switch-checked" />
<div role="switch" aria-checked="false" data-testid="aria-switch-unchecked" />

const inputCheckboxChecked = getByTestId('input-checkbox-checked')
const inputCheckboxUnchecked = getByTestId('input-checkbox-unchecked')
const ariaCheckboxChecked = getByTestId('aria-checkbox-checked')
const ariaCheckboxUnchecked = getByTestId('aria-checkbox-unchecked')
expect(inputCheckboxChecked).to.be.checked
expect(inputCheckboxUnchecked).not.to.be.checked
expect(ariaCheckboxChecked).to.be.checked
expect(ariaCheckboxUnchecked).not.to.be.checked

const inputRadioChecked = getByTestId('input-radio-checked')
const inputRadioUnchecked = getByTestId('input-radio-unchecked')
const ariaRadioChecked = getByTestId('aria-radio-checked')
const ariaRadioUnchecked = getByTestId('aria-radio-unchecked')
expect(inputRadioChecked).to.be.checked
expect(inputRadioUnchecked).not.to.be.checked
expect(ariaRadioChecked).to.be.checked
expect(ariaRadioUnchecked).not.to.be.checked

const ariaSwitchChecked = getByTestId('aria-switch-checked')
const ariaSwitchUnchecked = getByTestId('aria-switch-unchecked')
expect(ariaSwitchChecked).to.be.checked
expect(ariaSwitchUnchecked).not.to.be.checked

---

.partially

This allows you to check whether the given element is partially checked when used before .checked. It accepts an input of type checkbox and elements with a role of checkbox with a aria-checked="mixed", or input of type checkbox with indeterminate set to true

Examples

<input type="checkbox" aria-checked="mixed" data-testid="aria-checkbox-mixed" />
<input type="checkbox" checked data-testid="input-checkbox-checked" />
<input type="checkbox" data-testid="input-checkbox-unchecked" />
<div role="checkbox" aria-checked="true" data-testid="aria-checkbox-checked" />
<div
  role="checkbox"
  aria-checked="false"
  data-testid="aria-checkbox-unchecked"
/>
<input type="checkbox" data-testid="input-checkbox-indeterminate" />

const ariaCheckboxMixed = getByTestId('aria-checkbox-mixed')
const inputCheckboxChecked = getByTestId('input-checkbox-checked')
const inputCheckboxUnchecked = getByTestId('input-checkbox-unchecked')
const ariaCheckboxChecked = getByTestId('aria-checkbox-checked')
const ariaCheckboxUnchecked = getByTestId('aria-checkbox-unchecked')
const inputCheckboxIndeterminate = getByTestId('input-checkbox-indeterminate')

expect(ariaCheckboxMixed).to.be.partially.checked
expect(inputCheckboxChecked).not.to.be.partially.checked
expect(inputCheckboxUnchecked).not.to.be.partially.checked
expect(ariaCheckboxChecked).not.to.be.partially.checked
expect(ariaCheckboxUnchecked).not.to.be.partially.checked

inputCheckboxIndeterminate.indeterminate = true
expect(inputCheckboxIndeterminate).to.be.partially.checked

---

.error

This allows you to check whether the given element has an ARIA error message or not.

Every assertion done after this will be done on the error message of the element being tested.

Use the aria-errormessage attribute to reference another element that contains custom error message text. Multiple ids is NOT allowed. Authors MUST use aria-invalid in conjunction with aria-errormessage. Learn more from aria-errormessage spec.

Whitespace is normalized.

Examples

<label for="startTime"> Please enter a start time for the meeting: </label>
<input
  id="startTime"
  type="text"
  aria-errormessage="msgID"
  aria-invalid="true"
  value="11:30 PM"
/>
<span id="msgID" aria-live="assertive" style="visibility:visible">
  Invalid time: the time must be between 9:00 AM and 5:00 PM
</span>

const timeInput = getByLabel('startTime')

expect(timeInput).to.have.error(
  'Invalid time: the time must be between 9:00 AM and 5:00 PM',
)
expect(timeInput).to.have.error.that.matches(/invalid time/i) // to partially match
expect(timeInput).to.have.error.that.contains('Invalid time') // to partially match
expect(timeInput).to.have.error.that.does.not.contain('Pikachu!')