feat(eslint-plugin): add new @elastic/eui/callout-announce-on-mount rule

packages/eslint-plugin/README.md

@@ -147,9 +147,13 @@ Ensure `EuiIconTip` is used rather than `<EuiToolTip><EuiIcon/></EuiToolTip>`, a
 
 Ensure that all radio input components (`EuiRadio`, `EuiRadioGroup`) have a `name` attribute. The `name` attribute is required for radio inputs to be grouped correctly, allowing users to select only one option from a set. Without a `name`, radios may not behave as expected and can cause accessibility issues for assistive technologies.
 
+### `@elastic/eui/callout-announce-on-mount`
+
+Ensures that `EuiCallOut` components rendered conditionally have the `announceOnMount` prop for better accessibility. When callouts appear dynamically (e.g., after user interactions, form validation errors, or status changes), screen readers may not announce their content to users. The `announceOnMount` prop ensures these messages are properly announced to users with assistive technologies.
+
 ### `@elastic/eui/no-unnamed-interactive-element`
-Ensure that appropriate aria-attributes are set for `EuiBetaBadge`, `EuiButtonIcon`, `EuiComboBox`, `EuiSelect`, `EuiSelectWithWidth`,`EuiSuperSelect`,`EuiPagination`, `EuiTreeView`, `EuiBreadcrumbs`. Without this rule, screen reader users lose context, keyboard navigation can be confusing.
 
+Ensure that appropriate aria-attributes are set for `EuiBetaBadge`, `EuiButtonIcon`, `EuiComboBox`, `EuiSelect`, `EuiSelectWithWidth`,`EuiSuperSelect`,`EuiPagination`, `EuiTreeView`, `EuiBreadcrumbs`. Without this rule, screen reader users lose context, keyboard navigation can be confusing.
 
 ## Testing
 

packages/eslint-plugin/changelogs/upcoming/9005.md

@@ -0,0 +1 @@
+- Added new `callout-announce-on-mount` rule.

packages/eslint-plugin/src/index.ts

@@ -17,6 +17,7 @@
  * under the License.
  */
 
+import { CallOutAnnounceOnMount } from './rules/a11y/callout_announce_on_mount';
 import { HrefOnClick } from './rules/href_or_on_click';
 import { NoRestrictedEuiImports } from './rules/no_restricted_eui_imports';
 import { NoCssColor } from './rules/no_css_color';
@@ -39,6 +40,7 @@ const config = {
     'sr-output-disabled-tooltip': ScreenReaderOutputDisabledTooltip,
     'prefer-eui-icon-tip': PreferEuiIconTip,
     'no-unnamed-radio-group' : NoUnnamedRadioGroup,
+    'callout-announce-on-mount': CallOutAnnounceOnMount,
     'no-unnamed-interactive-element': NoUnnamedInteractiveElement, 
   },
   configs: {
@@ -53,6 +55,7 @@ const config = {
         '@elastic/eui/sr-output-disabled-tooltip': 'warn',
         '@elastic/eui/prefer-eui-icon-tip': 'warn',
         '@elastic/eui/no-unnamed-radio-group': 'warn',
+        '@elastic/eui/callout-announce-on-mount': 'warn',
         '@elastic/eui/no-unnamed-interactive-element': 'warn',      
       },
     },

packages/eslint-plugin/src/rules/a11y/callout_announce_on_mount.test.ts

@@ -0,0 +1,225 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { CallOutAnnounceOnMount } from './callout_announce_on_mount';
+import { RuleTester } from '@typescript-eslint/rule-tester';
+import dedent from 'dedent';
+
+const languageOptions = {
+  parserOptions: {
+    ecmaFeatures: {
+      jsx: true,
+    },
+  },
+};
+
+const ruleTester = new RuleTester();
+
+ruleTester.run('callout-announce-on-mount', CallOutAnnounceOnMount, {
+  valid: [
+    {
+      code: dedent`
+        const MyComponent = () => (
+          <EuiCallOut title="Always visible callout">
+            This callout is always rendered
+          </EuiCallOut>
+        )
+      `,
+      languageOptions,
+    },
+    {
+      code: dedent`
+        const MyComponent = ({ condition }) => (
+          condition && <EuiCallOut announceOnMount title="Error">
+            Something went wrong
+          </EuiCallOut>
+        )
+      `,
+      languageOptions,
+    },
+    {
+      code: dedent`
+        const MyComponent = ({ condition }) => (
+          condition ? <EuiCallOut announceOnMount title="Success">
+            Operation completed
+          </EuiCallOut> : null
+        )
+      `,
+      languageOptions,
+    },
+    {
+      code: dedent`
+        const MyComponent = ({ condition }) => {
+          if (condition) {
+            return <EuiCallOut announceOnMount title="Warning">
+              Please check your input
+            </EuiCallOut>
+          }
+          return null;
+        }
+      `,
+      languageOptions,
+    },
+    {
+      code: dedent`
+        const MyComponent = () => (
+          <div>
+            <EuiCallOut title="Static callout">
+              This is not conditionally rendered
+            </EuiCallOut>
+          </div>
+        )
+      `,
+      languageOptions,
+    },
+  ],
+  invalid: [
+    {
+      code: dedent`
+        const MyComponent = ({ condition }) => (
+          condition && <EuiCallOut title="Error">
+            Something went wrong
+          </EuiCallOut>
+        )
+      `,
+      output: dedent`
+        const MyComponent = ({ condition }) => (
+          condition && <EuiCallOut announceOnMount title="Error">
+            Something went wrong
+          </EuiCallOut>
+        )
+      `,
+      languageOptions,
+      errors: [{ messageId: 'missingAnnounceOnMount' }],
+    },
+    {
+      code: dedent`
+        const MyComponent = ({ condition }) => (
+          condition ? <EuiCallOut title="Success">
+            Operation completed
+          </EuiCallOut> : null
+        )
+      `,
+      output: dedent`
+        const MyComponent = ({ condition }) => (
+          condition ? <EuiCallOut announceOnMount title="Success">
+            Operation completed
+          </EuiCallOut> : null
+        )
+      `,
+      languageOptions,
+      errors: [{ messageId: 'missingAnnounceOnMount' }],
+    },
+    {
+      code: dedent`
+        const MyComponent = ({ condition }) => {
+          if (condition) {
+            return <EuiCallOut title="Warning">
+              Please check your input
+            </EuiCallOut>
+          }
+          return null;
+        }
+      `,
+      output: dedent`
+        const MyComponent = ({ condition }) => {
+          if (condition) {
+            return <EuiCallOut announceOnMount title="Warning">
+              Please check your input
+            </EuiCallOut>
+          }
+          return null;
+        }
+      `,
+      languageOptions,
+      errors: [{ messageId: 'missingAnnounceOnMount' }],
+    },
+    {
+      code: dedent`
+        const MyComponent = ({ condition }) => (
+          <div>
+            {!condition && <EuiCallOut title="Validation Error">
+              Form contains errors
+            </EuiCallOut>}
+          </div>
+        )
+      `,
+      output: dedent`
+        const MyComponent = ({ condition }) => (
+          <div>
+            {!condition && <EuiCallOut announceOnMount title="Validation Error">
+              Form contains errors
+            </EuiCallOut>}
+          </div>
+        )
+      `,
+      languageOptions,
+      errors: [{ messageId: 'missingAnnounceOnMount' }],
+    },
+    {
+      code: dedent`
+        const MyComponent = ({ status }) => {
+          let notification;
+
+          if (status === 'success') {
+            notification = (
+              <EuiCallOut
+                title="Task completed successfully"
+              />
+            );
+          } else if (status === 'error') {
+            notification = (
+              <EuiCallOut
+                title="Something went wrong"
+              />
+            );
+          }
+
+          return <div>{notification}</div>;
+        }
+      `,
+      output: dedent`
+        const MyComponent = ({ status }) => {
+          let notification;
+
+          if (status === 'success') {
+            notification = (
+              <EuiCallOut announceOnMount
+                title="Task completed successfully"
+              />
+            );
+          } else if (status === 'error') {
+            notification = (
+              <EuiCallOut announceOnMount
+                title="Something went wrong"
+              />
+            );
+          }
+
+          return <div>{notification}</div>;
+        }
+      `,
+      languageOptions,
+      errors: [
+        { messageId: 'missingAnnounceOnMount' },
+        { messageId: 'missingAnnounceOnMount' },
+      ],
+    },
+  ],
+});

packages/eslint-plugin/src/rules/a11y/callout_announce_on_mount.ts

@@ -0,0 +1,80 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import {  ESLintUtils } from '@typescript-eslint/utils';
+import { isInConditionalRendering } from '../../utils/is_in_conditional_rendering';
+import { hasSpread } from '../../utils/has_spread';
+
+const CALLOUT_COMPONENT = 'EuiCallOut';
+
+export const CallOutAnnounceOnMount = ESLintUtils.RuleCreator.withoutDocs({
+  create(context) {
+    return {
+      JSXElement(node) {
+        const { openingElement } = node;
+        if (openingElement.name.type !== 'JSXIdentifier' || 
+            openingElement.name.name !== CALLOUT_COMPONENT) {
+          return;
+        }
+        if (openingElement.attributes.some(attr => 
+          attr.type === 'JSXAttribute' &&
+          attr.name.type === 'JSXIdentifier' &&
+          attr.name.name === 'announceOnMount'
+        )) {
+          return;
+        }
+        if (isInConditionalRendering(node)) {
+          context.report({
+            node: openingElement,
+            messageId: 'missingAnnounceOnMount',
+            fix: hasSpread(openingElement.attributes) ? undefined : (fixer) => {
+              return fixer.insertTextAfterRange(
+                [openingElement.name.range[1], openingElement.name.range[1]], 
+                ' announceOnMount'
+              );
+            },
+          });
+        }
+      },
+    };
+  },
+  meta: {
+    type: 'problem',
+    docs: {
+      description: `Ensure ${CALLOUT_COMPONENT} components that are conditionally rendered have announceOnMount prop for better accessibility`
+    },
+    fixable: 'code',
+    schema: [],
+    messages: {
+      missingAnnounceOnMount: [
+        `${CALLOUT_COMPONENT} should have \`announceOnMount\` prop when conditionally rendered for better accessibility.`,
+        '\n',
+        `When ${CALLOUT_COMPONENT} appears dynamically (e.g., after user interaction, form validation, etc.),`,
+        'screen readers may not announce its content. Adding `announceOnMount` ensures the callout',
+        'is properly announced to users with assistive technologies.',
+        '\n',
+        'Example:',
+        `  <${CALLOUT_COMPONENT} announceOnMount title="Error" color="danger">`,
+        '    This message will be announced when it appears',
+        `  </${CALLOUT_COMPONENT}>`,
+      ].join('\n'),
+    },
+  },
+  defaultOptions: [],
+});

packages/eslint-plugin/src/utils/is_in_conditional_rendering.ts

@@ -0,0 +1,33 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { TSESTree } from '@typescript-eslint/utils';
+
+export function isInConditionalRendering(node: TSESTree.JSXElement): boolean {
+  let parent: TSESTree.Node | undefined = node.parent;
+  while (parent) {
+    if (parent.type === 'ConditionalExpression' || 
+      parent.type === 'IfStatement' ||
+      (parent.type === 'LogicalExpression' && parent.operator === '&&')) {
+      return true;
+    }
+    parent = parent.parent;
+  }
+  return false;
+}