feat: toHaveAccessibleName and toHaveAccessibleDescription (#377)

* Add toHaveAccessibleName
* Add toHaveAccessibleDescription
* Update README.md

Co-authored-by: Sebastian Silbermann <silbermann.sebastian@gmail.com>

Author: gnapse

README.md

@@ -64,6 +64,8 @@ clear to read and to maintain.
   - [`toBeVisible`](#tobevisible)
   - [`toContainElement`](#tocontainelement)
   - [`toContainHTML`](#tocontainhtml)
+  - [`toHaveAccessibleDescription`](#tohaveaccessibledescription)
+  - [`toHaveAccessibleName`](#tohaveaccessiblename)
   - [`toHaveAttribute`](#tohaveattribute)
   - [`toHaveClass`](#tohaveclass)
   - [`toHaveFocus`](#tohavefocus)
@@ -155,8 +157,7 @@ toBeDisabled()
 ```
 
 This allows you to check whether an element is disabled from the user's
-perspective.
-According to the specification, the following elements can be
+perspective. According to the specification, the following elements can be
 [disabled](https://html.spec.whatwg.org/multipage/semantics-other.html#disabled-elements):
 `button`, `input`, `select`, `textarea`, `optgroup`, `option`, `fieldset`.
 
@@ -526,6 +527,94 @@ expect(getByTestId('parent')).toContainHTML('</span>')
 
 <hr />
 
+### `toHaveAccessibleDescription`
+
+```typescript
+toHaveAccessibleDescription(expectedAccessibleDescription?: string | RegExp)
+```
+
+This allows to assert that an element has the expected
+[accessible description](https://w3c.github.io/accname/).
+
+You can pass the exact string of the expected accessible description, or you can
+make a partial match passing a regular expression, or by using
+[expect.stringContaining](https://jestjs.io/docs/en/expect.html#expectnotstringcontainingstring)/[expect.stringMatching](https://jestjs.io/docs/en/expect.html#expectstringmatchingstring-regexp).
+
+#### Examples
+
+```html
+<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>
+```
+
+```js
+expect(getByTestId('link')).toHaveAccessibleDescription()
+expect(getByTestId('link')).toHaveAccessibleDescription('A link to start over')
+expect(getByTestId('link')).not.toHaveAccessibleDescription('Home page')
+expect(getByTestId('extra-link')).not.toHaveAccessibleDescription()
+expect(getByTestId('avatar')).not.toHaveAccessibleDescription()
+expect(getByTestId('logo')).not.toHaveAccessibleDescription('Company logo')
+expect(getByTestId('logo')).toHaveAccessibleDescription(
+  'The logo of Our Company',
+)
+```
+
+<hr />
+
+### `toHaveAccessibleName`
+
+```typescript
+toHaveAccessibleName(expectedAccessibleName?: string | RegExp)
+```
+
+This allows to assert that an element is has the expected
+[accessible name](https://w3c.github.io/accname/). It is useful, for instance,
+to assert that form elements and buttons are properly labelled.
+
+You can pass the exact string of the expected accessible name, or you can make a
+partial match passing a regular expression, or by using
+[expect.stringContaining](https://jestjs.io/docs/en/expect.html#expectnotstringcontainingstring)/[expect.stringMatching](https://jestjs.io/docs/en/expect.html#expectstringmatchingstring-regexp).
+
+#### Examples
+
+```html
+<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" />
+```
+
+```javascript
+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()
+```
+
+<hr />
+
 ### `toHaveAttribute`
 
 ```typescript

package.json

@@ -37,6 +37,7 @@
     "chalk": "^3.0.0",
     "css": "^3.0.0",
     "css.escape": "^1.5.1",
+    "dom-accessibility-api": "^0.5.6",
     "lodash": "^4.17.15",
     "redent": "^3.0.0"
   },

src/__tests__/to-have-accessible-description.js

@@ -0,0 +1,59 @@
+import {render} from './helpers/test-utils'
+
+describe('.toHaveAccessibleDescription', () => {
+  it('works with the link title attribute', () => {
+    const {queryByTestId} = render(`
+      <div>
+        <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>
+      </div>
+   `)
+
+    const link = queryByTestId('link')
+    expect(link).toHaveAccessibleDescription()
+    expect(link).toHaveAccessibleDescription('A link to start over')
+    expect(link).not.toHaveAccessibleDescription('Home page')
+    expect(() => {
+      expect(link).toHaveAccessibleDescription('Invalid description')
+    }).toThrow(/expected element to have accessible description/i)
+    expect(() => {
+      expect(link).not.toHaveAccessibleDescription()
+    }).toThrow(/expected element not to have accessible description/i)
+
+    const extraLink = queryByTestId('extra-link')
+    expect(extraLink).not.toHaveAccessibleDescription()
+    expect(() => {
+      expect(extraLink).toHaveAccessibleDescription()
+    }).toThrow(/expected element to have accessible description/i)
+  })
+
+  it('works with aria-describedby attributes', () => {
+    const {queryByTestId} = render(`
+      <div>
+        <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>
+      </div>
+   `)
+
+    const avatar = queryByTestId('avatar')
+    expect(avatar).not.toHaveAccessibleDescription()
+    expect(() => {
+      expect(avatar).toHaveAccessibleDescription('User profile pic')
+    }).toThrow(/expected element to have accessible description/i)
+
+    const logo = queryByTestId('logo')
+    expect(logo).not.toHaveAccessibleDescription('Company logo')
+    expect(logo).toHaveAccessibleDescription('The logo of Our Company')
+    expect(logo).toHaveAccessibleDescription(/logo of our company/i)
+    expect(logo).toHaveAccessibleDescription(
+      expect.stringContaining('logo of Our Company'),
+    )
+    expect(() => {
+      expect(logo).toHaveAccessibleDescription("Our company's logo")
+    }).toThrow(/expected element to have accessible description/i)
+    expect(() => {
+      expect(logo).not.toHaveAccessibleDescription('The logo of Our Company')
+    }).toThrow(/expected element not to have accessible description/i)
+  })
+})