Add rule to prevent duplicate labels on TextInput

.changeset/gold-pigs-carry.md

@@ -0,0 +1,5 @@
+---
+'eslint-plugin-primer-react': patch
+---
+
+Add `a11y-no-duplicate-form-labels` rule to prevent duplicate labels on TextInput components.

docs/rules/a11y-no-duplicate-form-labels.md

@@ -0,0 +1,48 @@
+## Rule Details
+
+This rule prevents accessibility issues by ensuring form controls have only one label. When a `FormControl` contains both a `FormControl.Label` and a `TextInput` with an `aria-label`, it creates duplicate labels which can confuse screen readers and other assistive technologies.
+
+👎 Examples of **incorrect** code for this rule:
+
+```jsx
+import {FormControl, TextInput} from '@primer/react'
+
+function ExampleComponent() {
+  return (
+    // TextInput has aria-label when FormControl.Label is present
+    <FormControl>
+      <FormControl.Label>Form Input Label</FormControl.Label>
+      <TextInput aria-label="Form Input Label" />
+    </FormControl>
+  )
+}
+```
+
+👍 Examples of **correct** code for this rule:
+
+```jsx
+import {FormControl, TextInput} from '@primer/react'
+
+function ExampleComponent() {
+  return (
+    <>
+      {/* TextInput without aria-label when FormControl.Label is present */}
+      <FormControl>
+        <FormControl.Label>Form Input Label</FormControl.Label>
+        <TextInput />
+      </FormControl>
+
+      {/* TextInput with aria-label when no FormControl.Label is present */}
+      <FormControl>
+        <TextInput aria-label="Form Input Label" />
+      </FormControl>
+
+      {/* Using visuallyHidden FormControl.Label without aria-label */}
+      <FormControl>
+        <FormControl.Label visuallyHidden>Form Input Label</FormControl.Label>
+        <TextInput />
+      </FormControl>
+    </>
+  )
+}
+```

src/configs/recommended.js

@@ -17,6 +17,7 @@ module.exports = {
     'primer-react/new-color-css-vars': 'error',
     'primer-react/a11y-explicit-heading': 'error',
     'primer-react/a11y-no-title-usage': 'error',
+    'primer-react/a11y-no-duplicate-form-labels': 'error',
     'primer-react/no-deprecated-props': 'warn',
     'primer-react/a11y-remove-disable-tooltip': 'error',
     'primer-react/a11y-use-accessible-tooltip': 'error',

src/index.js

@@ -12,6 +12,7 @@ module.exports = {
     'a11y-remove-disable-tooltip': require('./rules/a11y-remove-disable-tooltip'),
     'a11y-use-accessible-tooltip': require('./rules/a11y-use-accessible-tooltip'),
     'a11y-no-title-usage': require('./rules/a11y-no-title-usage'),
+    'a11y-no-duplicate-form-labels': require('./rules/a11y-no-duplicate-form-labels'),
     'use-deprecated-from-deprecated': require('./rules/use-deprecated-from-deprecated'),
     'no-wildcard-imports': require('./rules/no-wildcard-imports'),
     'no-unnecessary-components': require('./rules/no-unnecessary-components'),

src/rules/__tests__/a11y-no-duplicate-form-labels.test.js

@@ -0,0 +1,112 @@
+const rule = require('../a11y-no-duplicate-form-labels')
+const {RuleTester} = require('eslint')
+
+const ruleTester = new RuleTester({
+  parserOptions: {
+    ecmaVersion: 'latest',
+    sourceType: 'module',
+    ecmaFeatures: {
+      jsx: true,
+    },
+  },
+})
+
+ruleTester.run('a11y-no-duplicate-form-labels', rule, {
+  valid: [
+    // TextInput without aria-label is valid
+    `import {FormControl, TextInput} from '@primer/react';
+    <FormControl>
+      <FormControl.Label>Form Input Label</FormControl.Label>
+      <TextInput />
+    </FormControl>`,
+
+    // TextInput with aria-label but no FormControl.Label is valid
+    `import {FormControl, TextInput} from '@primer/react';
+    <FormControl>
+      <TextInput aria-label="Form Input Label" />
+    </FormControl>`,
+
+    // TextInput with aria-label outside FormControl is valid
+    `import {TextInput} from '@primer/react';
+    <TextInput aria-label="Form Input Label" />`,
+
+    // TextInput with visuallyHidden FormControl.Label is valid
+    `import {FormControl, TextInput} from '@primer/react';
+    <FormControl>
+      <FormControl.Label visuallyHidden>Form Input Label</FormControl.Label>
+      <TextInput />
+    </FormControl>`,
+
+    // FormControl without FormControl.Label but with aria-label is valid
+    `import {FormControl, TextInput} from '@primer/react';
+    <FormControl>
+      <TextInput aria-label="Form Input Label" />
+    </FormControl>`,
+
+    // Multiple TextInputs with different approaches
+    `import {FormControl, TextInput} from '@primer/react';
+    <div>
+      <FormControl>
+        <FormControl.Label>Visible Label</FormControl.Label>
+        <TextInput />
+      </FormControl>
+      <FormControl>
+        <TextInput aria-label="Standalone Input" />
+      </FormControl>
+    </div>`,
+  ],
+  invalid: [
+    {
+      code: `import {FormControl, TextInput} from '@primer/react';
+      <FormControl>
+        <FormControl.Label>Form Input Label</FormControl.Label>
+        <TextInput aria-label="Form Input Label" />
+      </FormControl>`,
+      errors: [
+        {
+          messageId: 'duplicateLabel',
+        },
+      ],
+    },
+    {
+      code: `import {FormControl, TextInput} from '@primer/react';
+      <FormControl>
+        <FormControl.Label>Username</FormControl.Label>
+        <TextInput aria-label="Enter your username" />
+      </FormControl>`,
+      errors: [
+        {
+          messageId: 'duplicateLabel',
+        },
+      ],
+    },
+    {
+      code: `import {FormControl, TextInput} from '@primer/react';
+      <FormControl>
+        <FormControl.Label visuallyHidden>Password</FormControl.Label>
+        <TextInput aria-label="Enter password" />
+      </FormControl>`,
+      errors: [
+        {
+          messageId: 'duplicateLabel',
+        },
+      ],
+    },
+    {
+      code: `import {FormControl, TextInput} from '@primer/react';
+      <div>
+        <FormControl>
+          <FormControl.Label>Email</FormControl.Label>
+          <div>
+            <TextInput aria-label="Email address" />
+          </div>
+        </FormControl>
+      </div>`,
+      errors: [
+        {
+          messageId: 'duplicateLabel',
+        },
+      ],
+    },
+  ],
+})

src/rules/a11y-no-duplicate-form-labels.js

@@ -0,0 +1,69 @@
+const {isPrimerComponent} = require('../utils/is-primer-component')
+const {getJSXOpeningElementName} = require('../utils/get-jsx-opening-element-name')
+const {getJSXOpeningElementAttribute} = require('../utils/get-jsx-opening-element-attribute')
+
+const isFormControl = node => getJSXOpeningElementName(node) === 'FormControl'
+const isFormControlLabel = node => getJSXOpeningElementName(node) === 'FormControl.Label'
+const isTextInput = node => getJSXOpeningElementName(node) === 'TextInput'
+
+const hasAriaLabel = node => {
+  const ariaLabel = getJSXOpeningElementAttribute(node, 'aria-label')
+  return !!ariaLabel
+}
+
+const findFormControlLabel = (node, sourceCode) => {
+  // Traverse up the parent chain to find FormControl
+  let current = node.parent
+  while (current) {
+    if (
+      current.type === 'JSXElement' &&
+      isFormControl(current.openingElement) &&
+      isPrimerComponent(current.openingElement.name, sourceCode.getScope(current))
+    ) {
+      // Found FormControl, now check if it has a FormControl.Label child
+      return current.children.some(
+        child =>
+          child.type === 'JSXElement' &&
+          isFormControlLabel(child.openingElement) &&
+          isPrimerComponent(child.openingElement.name, sourceCode.getScope(child)),
+      )
+    }
+    current = current.parent
+  }
+  return false
+}
+
+module.exports = {
+  meta: {
+    type: 'problem',
+    docs: {
+      description:
+        'Prevent duplicate labels on form inputs by disallowing aria-label on TextInput when FormControl.Label is present.',
+      url: require('../url')(module),
+    },
+    schema: [],
+    messages: {
+      duplicateLabel:
+        'TextInput should not have aria-label when FormControl.Label is present. Use FormControl.Label with visuallyHidden prop if needed.',
+    },
+  },
+  create(context) {
+    const sourceCode = context.sourceCode ?? context.getSourceCode()
+    return {
+      JSXOpeningElement(jsxNode) {
+        if (isPrimerComponent(jsxNode.name, sourceCode.getScope(jsxNode)) && isTextInput(jsxNode)) {
+          // Check if TextInput has aria-label
+          if (hasAriaLabel(jsxNode)) {
+            // Check if there's a FormControl.Label in the parent FormControl
+            if (findFormControlLabel(jsxNode, sourceCode)) {
+              context.report({
+                node: jsxNode,
+                messageId: 'duplicateLabel',
+              })
+            }
+          }
+        }
+      },
+    }
+  },
+}