README.md

@@ -64,6 +64,7 @@ clear to read and to maintain.
   - [`toContainElement`](#tocontainelement)
   - [`toContainHTML`](#tocontainhtml)
   - [`toHaveAccessibleDescription`](#tohaveaccessibledescription)
+  - [`toHaveAccessibleErrorMessage`](#tohaveaccessibleerrormessage)
   - [`toHaveAccessibleName`](#tohaveaccessiblename)
   - [`toHaveAttribute`](#tohaveattribute)
   - [`toHaveClass`](#tohaveclass)
@@ -561,6 +562,63 @@ expect(getByTestId('logo')).toHaveAccessibleDescription(
 
 <hr />
 
+### `toHaveAccessibleErrorMessage`
+
+```typescript
+toHaveAccessibleErrorMessage(expectedAccessibleErrorMessage?: string | RegExp)
+```
+
+This allows you to assert that an element has the expected
+[accessible error message](https://w3c.github.io/aria/#aria-errormessage).
+
+You can pass the exact string of the expected accessible error message.
+Alternatively, you can perform a partial match by 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
+<input
+  aria-label="Has Error"
+  aria-invalid="true"
+  aria-errormessage="error-message"
+/>
+<div id="error-message" role="alert">This field is invalid</div>
+
+<input aria-label="No Error Attributes" />
+<input
+  aria-label="Not Invalid"
+  aria-invalid="false"
+  aria-errormessage="error-message"
+/>
+```
+
+```js
+// Inputs with Valid Error Messages
+expect(getByRole('textbox', {name: 'Has Error'})).toHaveAccessibleErrorMessage()
+expect(getByRole('textbox', {name: 'Has Error'})).toHaveAccessibleErrorMessage(
+  'This field is invalid',
+)
+expect(getByRole('textbox', {name: 'Has Error'})).toHaveAccessibleErrorMessage(
+  /invalid/i,
+)
+expect(
+  getByRole('textbox', {name: 'Has Error'}),
+).not.toHaveAccessibleErrorMessage('This field is absolutely correct!')
+
+// Inputs without Valid Error Messages
+expect(
+  getByRole('textbox', {name: 'No Error Attributes'}),
+).not.toHaveAccessibleErrorMessage()
+
+expect(
+  getByRole('textbox', {name: 'Not Invalid'}),
+).not.toHaveAccessibleErrorMessage()
+```
+
+<hr />
+
 ### `toHaveAccessibleName`
 
 ```typescript
@@ -1069,6 +1127,10 @@ expect(inputCheckboxIndeterminate).toBePartiallyChecked()
 
 ### `toHaveErrorMessage`
 
+> This custom matcher is deprecated. Prefer
+> [`toHaveAccessibleErrorMessage`](#tohaveaccessibleerrormessage) instead, which
+> is more comprehensive in implementing the official spec.
+
 ```typescript
 toHaveErrorMessage(text: string | RegExp)
 ```

package.json

@@ -35,7 +35,7 @@
     "@types/testing-library__jest-dom": "^5.9.1",
     "aria-query": "^5.0.0",
     "chalk": "^3.0.0",
-    "css": "^3.0.0",
+    "@adobe/css-tools": "^4.0.1",
     "css.escape": "^1.5.1",
     "dom-accessibility-api": "^0.5.6",
     "lodash": "^4.17.15",

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

@@ -0,0 +1,277 @@
+import {render} from './helpers/test-utils'
+
+describe('.toHaveAccessibleErrorMessage', () => {
+  const input = 'input'
+  const errorId = 'error-id'
+  const error = 'This field is invalid'
+  const strings = {true: String(true), false: String(false)}
+
+  describe('Positive Test Cases', () => {
+    it("Fails the test if an invalid `id` is provided for the target element's `aria-errormessage`", () => {
+      const secondId = 'id2'
+      const secondError = 'LISTEN TO ME!!!'
+
+      const {queryByTestId} = render(`
+        <div>
+          <${input} data-testid="${input}" aria-invalid="${strings.true}" aria-errormessage="${errorId} ${secondId}" />
+          <div data-testid="${errorId}" id="${errorId}" role="alert">${error}</div>
+          <div data-testid="${secondId}" id="${secondId}" role="alert">${secondError}</div>
+        </div>
+      `)
+
+      const field = queryByTestId('input')
+      expect(() => expect(field).toHaveAccessibleErrorMessage())
+        .toThrowErrorMatchingInlineSnapshot(`
+        <dim>expect(</><red>element</><dim>).toHaveAccessibleErrorMessage(</><green>expected</><dim>)</>
+
+        Expected element's \`aria-errormessage\` attribute to be empty or a single, valid ID:
+
+        Received:
+        <red>  aria-errormessage="error-id id2"</>
+      `)
+
+      // Assume the remaining error messages are the EXACT same as above
+      expect(() =>
+        expect(field).toHaveAccessibleErrorMessage(new RegExp(error[0])),
+      ).toThrow()
+
+      expect(() => expect(field).toHaveAccessibleErrorMessage(error)).toThrow()
+      expect(() =>
+        expect(field).toHaveAccessibleErrorMessage(secondError),
+      ).toThrow()
+
+      expect(() =>
+        expect(field).toHaveAccessibleErrorMessage(new RegExp(secondError[0])),
+      ).toThrow()
+    })
+
+    it('Fails the test if the target element is valid according to the WAI-ARIA spec', () => {
+      const noAriaInvalidAttribute = 'no-aria-invalid-attribute'
+      const validFieldState = 'false'
+      const invalidFieldStates = [
+        'true',
+        '',
+        'grammar',
+        'spelling',
+        'asfdafbasdfasa',
+      ]
+
+      function renderFieldWithState(state) {
+        return render(`
+          <div>
+            <${input} data-testid="${input}" aria-invalid="${state}" aria-errormessage="${errorId}" />
+            <div data-testid="${errorId}" id="${errorId}" role="alert">${error}</div>
+            
+            <input data-testid="${noAriaInvalidAttribute}" aria-errormessage="${errorId}" />
+          </div>
+        `)
+      }
+
+      // Success Cases
+      invalidFieldStates.forEach(invalidState => {
+        const {queryByTestId} = renderFieldWithState(invalidState)
+        const field = queryByTestId('input')
+
+        expect(field).toHaveAccessibleErrorMessage()
+        expect(field).toHaveAccessibleErrorMessage(error)
+      })
+
+      // Failure Case
+      const {queryByTestId} = renderFieldWithState(validFieldState)
+      const field = queryByTestId('input')
+      const fieldWithoutAttribute = queryByTestId(noAriaInvalidAttribute)
+
+      expect(() => expect(fieldWithoutAttribute).toHaveAccessibleErrorMessage())
+        .toThrowErrorMatchingInlineSnapshot(`
+        <dim>expect(</><red>element</><dim>).toHaveAccessibleErrorMessage(</><green>expected</><dim>)</>
+
+        Expected element to be marked as invalid with attribute:
+        <green>  aria-invalid="true"</>
+        Received:
+        <red>  null</>
+      `)
+
+      expect(() => expect(field).toHaveAccessibleErrorMessage())
+        .toThrowErrorMatchingInlineSnapshot(`
+        <dim>expect(</><red>element</><dim>).toHaveAccessibleErrorMessage(</><green>expected</><dim>)</>
+
+        Expected element to be marked as invalid with attribute:
+        <green>  aria-invalid="true"</>
+        Received:
+        <red>  aria-invalid="false</>
+      `)
+
+      // Assume the remaining error messages are the EXACT same as above
+      expect(() => expect(field).toHaveAccessibleErrorMessage(error)).toThrow()
+      expect(() =>
+        expect(field).toHaveAccessibleErrorMessage(new RegExp(error, 'i')),
+      ).toThrow()
+    })
+
+    it('Passes the test if the target element has ANY recognized, non-empty error message', () => {
+      const {queryByTestId} = render(`
+        <div>
+          <${input} data-testid="${input}" aria-invalid="${strings.true}" aria-errormessage="${errorId}" />
+          <div data-testid="${errorId}" id="${errorId}" role="alert">${error}</div>
+        </div>
+      `)
+
+      const field = queryByTestId(input)
+      expect(field).toHaveAccessibleErrorMessage()
+    })
+
+    it('Fails the test if NO recognized, non-empty error message was found for the target element', () => {
+      const empty = 'empty'
+      const emptyErrorId = 'empty-error'
+      const missing = 'missing'
+
+      const {queryByTestId} = render(`
+        <div>
+          <input data-testid="${empty}" aria-invalid="${strings.true}" aria-errormessage="${emptyErrorId}" />
+          <div data-testid="${emptyErrorId}" id="${emptyErrorId}" role="alert"></div>
+
+          <input data-testid="${missing}" aria-invalid="${strings.true}" aria-errormessage="${missing}-error" />
+        </div>
+      `)
+
+      const fieldWithEmptyError = queryByTestId(empty)
+      const fieldMissingError = queryByTestId(missing)
+
+      expect(() => expect(fieldWithEmptyError).toHaveAccessibleErrorMessage())
+        .toThrowErrorMatchingInlineSnapshot(`
+        <dim>expect(</><red>element</><dim>).toHaveAccessibleErrorMessage(</><green>expected</><dim>)</>
+
+        Expected element to have accessible error message:
+
+        Received:
+
+      `)
+
+      expect(() => expect(fieldMissingError).toHaveAccessibleErrorMessage())
+        .toThrowErrorMatchingInlineSnapshot(`
+        <dim>expect(</><red>element</><dim>).toHaveAccessibleErrorMessage(</><green>expected</><dim>)</>
+
+        Expected element to have accessible error message:
+
+        Received:
+
+      `)
+    })
+
+    it('Passes the test if the target element has the error message that was SPECIFIED', () => {
+      const {queryByTestId} = render(`
+        <div>
+          <${input} data-testid="${input}" aria-invalid="${strings.true}" aria-errormessage="${errorId}" />
+          <div data-testid="${errorId}" id="${errorId}" role="alert">${error}</div>
+        </div>
+      `)
+
+      const field = queryByTestId(input)
+      const halfOfError = error.slice(0, Math.floor(error.length * 0.5))
+
+      expect(field).toHaveAccessibleErrorMessage(error)
+      expect(field).toHaveAccessibleErrorMessage(new RegExp(halfOfError), 'i')
+      expect(field).toHaveAccessibleErrorMessage(
+        expect.stringContaining(halfOfError),
+      )
+      expect(field).toHaveAccessibleErrorMessage(
+        expect.stringMatching(new RegExp(halfOfError), 'i'),
+      )
+    })
+
+    it('Fails the test if the target element DOES NOT have the error message that was SPECIFIED', () => {
+      const {queryByTestId} = render(`
+        <div>
+          <${input} data-testid="${input}" aria-invalid="${strings.true}" aria-errormessage="${errorId}" />
+          <div data-testid="${errorId}" id="${errorId}" role="alert">${error}</div>
+        </div>
+      `)
+
+      const field = queryByTestId(input)
+      const msg = 'asdflkje2984fguyvb bnafdsasfa;lj'
+
+      expect(() => expect(field).toHaveAccessibleErrorMessage(''))
+        .toThrowErrorMatchingInlineSnapshot(`
+        <dim>expect(</><red>element</><dim>).toHaveAccessibleErrorMessage(</><green>expected</><dim>)</>
+
+        Expected element to have accessible error message:
+
+        Received:
+        <red>  This field is invalid</>
+      `)
+
+      // Assume this error is SIMILAR to the error above
+      expect(() => expect(field).toHaveAccessibleErrorMessage(msg)).toThrow()
+      expect(() =>
+        expect(field).toHaveAccessibleErrorMessage(
+          error.slice(0, Math.floor(error.length * 0.5)),
+        ),
+      ).toThrow()
+
+      expect(() =>
+        expect(field).toHaveAccessibleErrorMessage(new RegExp(msg), 'i'),
+      ).toThrowErrorMatchingInlineSnapshot(`
+        <dim>expect(</><red>element</><dim>).toHaveAccessibleErrorMessage(</><green>expected</><dim>)</>
+
+        Expected element to have accessible error message:
+        <green>  /asdflkje2984fguyvb bnafdsasfa;lj/</>
+        Received:
+        <red>  This field is invalid</>
+      `)
+    })
+
+    it('Normalizes the whitespace of the received error message', () => {
+      const {queryByTestId} = render(`
+        <div>
+          <${input} data-testid="${input}" aria-invalid="${strings.true}" aria-errormessage="${errorId}" />
+          <div data-testid="${errorId}" id="${errorId}" role="alert">
+            Step
+              1
+                of
+                  9000
+          </div>
+        </div>
+      `)
+
+      const field = queryByTestId(input)
+      expect(field).toHaveAccessibleErrorMessage('Step 1 of 9000')
+    })
+  })
+
+  // These tests for the `.not` use cases will help us cover our bases and complete test coverage
+  describe('Negated Test Cases', () => {
+    it("Passes the test if an invalid `id` is provided for the target element's `aria-errormessage`", () => {
+      const secondId = 'id2'
+      const secondError = 'LISTEN TO ME!!!'
+
+      const {queryByTestId} = render(`
+        <div>
+          <${input} data-testid="${input}" aria-invalid="${strings.true}" aria-errormessage="${errorId} ${secondId}" />
+          <div data-testid="${errorId}" id="${errorId}" role="alert">${error}</div>
+          <div data-testid="${secondId}" id="${secondId}" role="alert">${secondError}</div>
+        </div>
+      `)
+
+      const field = queryByTestId('input')
+      expect(field).not.toHaveAccessibleErrorMessage()
+      expect(field).not.toHaveAccessibleErrorMessage(error)
+      expect(field).not.toHaveAccessibleErrorMessage(new RegExp(error[0]))
+      expect(field).not.toHaveAccessibleErrorMessage(secondError)
+      expect(field).not.toHaveAccessibleErrorMessage(new RegExp(secondError[0]))
+    })
+
+    it('Passes the test if the target element is valid according to the WAI-ARIA spec', () => {
+      const {queryByTestId} = render(`
+        <div>
+          <${input} data-testid="${input}" aria-errormessage="${errorId}" />
+          <div data-testid="${errorId}" id="${errorId}" role="alert">${error}</div>
+        </div>
+      `)
+
+      const field = queryByTestId(input)
+      expect(field).not.toHaveAccessibleErrorMessage()
+      expect(field).not.toHaveAccessibleErrorMessage(error)
+      expect(field).not.toHaveAccessibleErrorMessage(new RegExp(error[0]))
+    })
+  })
+})