feat: add semantic html elements implicit role support to queryByRole/getByRole selectors (testing-library#262)

* Add aria-query library as a dependency

* Extend queryByRole to use aria-query ARIA roles to identify semantic HTML elements

Author: szabototo89

package.json

@@ -44,6 +44,7 @@
   "dependencies": {
     "@babel/runtime": "^7.4.3",
     "@sheerun/mutationobserver-shim": "^0.3.2",
+    "aria-query": "3.0.0",
     "pretty-format": "^24.7.0",
     "wait-for-expect": "^1.1.1"
   },

src/__tests__/element-queries.js

@@ -361,6 +361,61 @@ describe('query by test id', () => {
   })
 })
 
+test('queryAllByRole returns semantic html elements', () => {
+  const {queryAllByRole} = render(`
+    <form>
+      <h1>Heading 1</h1>
+      <h2>Heading 2</h2>
+      <h3>Heading 3</h3>
+      <h4>Heading 4</h4>
+      <h5>Heading 5</h5>
+      <h6>Heading 6</h6>
+      <ol>
+        <li></li>
+        <li></li>
+      </ol>
+      <ul>
+        <li></li>
+      </ul>
+      <input>
+      <input type="text">
+      <input type="checkbox">
+      <input type="radio">
+      <table>
+        <thead>
+          <tr>
+            <th></th>
+            <th scope="row"></th>
+          </tr>
+        </thead>
+        <tbody>
+          <tr></tr>
+          <tr></tr>
+        </tbody>
+      </table>
+      <table role="grid"></table>
+      <button>Button</button>
+    </form>
+  `)
+
+  expect(queryAllByRole(/table/i)).toHaveLength(1)
+  expect(queryAllByRole(/tabl/i, {exact: false})).toHaveLength(1)
+  expect(queryAllByRole(/columnheader/i)).toHaveLength(1)
+  expect(queryAllByRole(/rowheader/i)).toHaveLength(1)
+  expect(queryAllByRole(/grid/i)).toHaveLength(1)
+  expect(queryAllByRole(/form/i)).toHaveLength(1)
+  expect(queryAllByRole(/button/i)).toHaveLength(1)
+  expect(queryAllByRole(/heading/i)).toHaveLength(6)
+  expect(queryAllByRole('list')).toHaveLength(2)
+  expect(queryAllByRole(/listitem/i)).toHaveLength(3)
+  expect(queryAllByRole(/textbox/i)).toHaveLength(2)
+  expect(queryAllByRole(/checkbox/i)).toHaveLength(1)
+  expect(queryAllByRole(/radio/i)).toHaveLength(1)
+  expect(queryAllByRole('row')).toHaveLength(3)
+  expect(queryAllByRole(/rowgroup/i)).toHaveLength(2)
+  expect(queryAllByRole(/(table)|(textbox)/i)).toHaveLength(3)
+})
+
 test('getAll* matchers return an array', () => {
   const {
     getAllByAltText,

src/queries/role.js

@@ -1,6 +1,74 @@
-import {queryAllByAttribute, buildQueries} from './all-utils'
+import {buildQueries, fuzzyMatches, makeNormalizer, matches} from './all-utils'
+import {elementRoles} from 'aria-query'
 
-const queryAllByRole = queryAllByAttribute.bind(null, 'role')
+function buildElementRoleList(elementRolesMap) {
+  function makeElementSelector({name, attributes = []}) {
+    return `${name}${attributes
+      .map(({name: attributeName, value}) => `[${attributeName}=${value}]`)
+      .join('')}`
+  }
+
+  function getSelectorSpecificity({attributes = []}) {
+    return attributes.length
+  }
+
+  function bySelectorSpecificity(
+    {specificity: leftSpecificity},
+    {specificity: rightSpecificity},
+  ) {
+    return rightSpecificity - leftSpecificity
+  }
+
+  let result = []
+
+  for (const [element, roles] of elementRolesMap.entries()) {
+    result = [
+      ...result,
+      {
+        selector: makeElementSelector(element),
+        roles: Array.from(roles),
+        specificity: getSelectorSpecificity(element),
+      },
+    ]
+  }
+
+  return result.sort(bySelectorSpecificity)
+}
+
+const elementRoleList = buildElementRoleList(elementRoles)
+
+function queryAllByRole(
+  container,
+  role,
+  {exact = true, collapseWhitespace, trim, normalizer} = {},
+) {
+  const matcher = exact ? matches : fuzzyMatches
+  const matchNormalizer = makeNormalizer({collapseWhitespace, trim, normalizer})
+
+  function getImplicitAriaRole(currentNode) {
+    for (const {selector, roles} of elementRoleList) {
+      if (currentNode.matches(selector)) {
+        return [...roles]
+      }
+    }
+
+    return []
+  }
+
+  return Array.from(container.querySelectorAll('*')).filter(node => {
+    const isRoleSpecifiedExplicitly = node.hasAttribute('role')
+
+    if (isRoleSpecifiedExplicitly) {
+      return matcher(node.getAttribute('role'), node, role, matchNormalizer)
+    }
+
+    const implicitRoles = getImplicitAriaRole(node)
+
+    return implicitRoles.some(implicitRole =>
+      matcher(implicitRole, node, role, matchNormalizer),
+    )
+  })
+}
 
 const getMultipleError = (c, id) => `Found multiple elements by [role=${id}]`
 const getMissingError = (c, id) => `Unable to find an element by [role=${id}]`