feat: add toHaveAccessibleErrorMessage

packages/playwright-core/src/server/injected/injectedScript.ts

@@ -29,7 +29,7 @@ import type { CSSComplexSelectorList } from '../../utils/isomorphic/cssParser';
 import { generateSelector, type GenerateSelectorOptions } from './selectorGenerator';
 import type * as channels from '@protocol/channels';
 import { Highlight } from './highlight';
-import { getChecked, getAriaDisabled, getAriaRole, getElementAccessibleName, getElementAccessibleDescription, getReadonly } from './roleUtils';
+import { getChecked, getAriaDisabled, getAriaRole, getElementAccessibleName, getElementAccessibleDescription, getReadonly, getElementAccessibleErrorMessage } from './roleUtils';
 import { kLayoutSelectorNames, type LayoutSelectorName, layoutSelectorScore } from './layoutSelectorUtils';
 import { asLocator } from '../../utils/isomorphic/locatorGenerators';
 import type { Language } from '../../utils/isomorphic/locatorGenerators';
@@ -1321,6 +1321,8 @@ export class InjectedScript {
         received = getElementAccessibleName(element, false /* includeHidden */);
       } else if (expression === 'to.have.accessible.description') {
         received = getElementAccessibleDescription(element, false /* includeHidden */);
+      } else if (expression === 'to.have.accessible.error.message') {
+        received = getElementAccessibleErrorMessage(element, false /* includeHidden */);
       } else if (expression === 'to.have.role') {
         received = getAriaRole(element) || '';
       } else if (expression === 'to.have.title') {

packages/playwright-core/src/server/injected/roleUtils.ts

@@ -461,6 +461,38 @@ export function getElementAccessibleDescription(element: Element, includeHidden:
   return accessibleDescription;
 }
 
+export function getElementAccessibleErrorMessage(element: Element, includeHidden: boolean): string {
+  const cache = includeHidden ? cacheAccessibleErrorMessageHidden : cacheAccessibleErrorMessage;
+  let accessibleErrorMessage = cache?.get(element);
+
+  if (accessibleErrorMessage === undefined) {
+    accessibleErrorMessage = '';
+
+    const ariaInvalid = element.getAttribute('aria-invalid');
+    if (ariaInvalid === 'true') {
+      const errorMessageId = element.getAttribute('aria-errormessage');
+      if (errorMessageId) {
+        // Ensure the ID is valid (no whitespace)
+        if (!/\s+/.test(errorMessageId)) {
+          // Retrieve the element referenced by aria-errormessage.
+          const errorElement = element.ownerDocument.getElementById(errorMessageId);
+          if (errorElement) {
+            accessibleErrorMessage = asFlatString(
+                getTextAlternativeInternal(errorElement, {
+                  includeHidden,
+                  visitedElements: new Set(),
+                  embeddedInDescribedBy: { element: errorElement, hidden: isElementHiddenForAria(errorElement) },
+                })
+            );
+          }
+        }
+      }
+    }
+    cache?.set(element, accessibleErrorMessage);
+  }
+  return accessibleErrorMessage;
+}
+
 type AccessibleNameOptions = {
   visitedElements: Set<Element>,
   includeHidden?: boolean,
@@ -972,6 +1004,8 @@ let cacheAccessibleName: Map<Element, string> | undefined;
 let cacheAccessibleNameHidden: Map<Element, string> | undefined;
 let cacheAccessibleDescription: Map<Element, string> | undefined;
 let cacheAccessibleDescriptionHidden: Map<Element, string> | undefined;
+let cacheAccessibleErrorMessage: Map<Element, string> | undefined;
+let cacheAccessibleErrorMessageHidden: Map<Element, string> | undefined;
 let cacheIsHidden: Map<Element, boolean> | undefined;
 let cachePseudoContentBefore: Map<Element, string> | undefined;
 let cachePseudoContentAfter: Map<Element, string> | undefined;

packages/playwright/src/matchers/expect.ts

@@ -35,6 +35,7 @@ import {
   toContainText,
   toHaveAccessibleDescription,
   toHaveAccessibleName,
+  toHaveAccessibleErrorMessage,
   toHaveAttribute,
   toHaveClass,
   toHaveCount,
@@ -224,6 +225,7 @@ const customAsyncMatchers = {
   toContainText,
   toHaveAccessibleDescription,
   toHaveAccessibleName,
+  toHaveAccessibleErrorMessage,
   toHaveAttribute,
   toHaveClass,
   toHaveCount,

packages/playwright/src/matchers/matchers.ts

@@ -205,6 +205,18 @@ export function toHaveAccessibleName(
   }
 }
 
+export function toHaveAccessibleErrorMessage(
+  this: ExpectMatcherState,
+  locator: LocatorEx,
+  expected: string | RegExp,
+  options?: { timeout?: number; ignoreCase?: boolean },
+) {
+  return toMatchText.call(this, 'toHaveAccessibleErrorMessage', locator, 'Locator', async (isNot, timeout) => {
+    const expectedText = serializeExpectedTextValues([expected], { ignoreCase: options?.ignoreCase });
+    return await locator._expect('to.have.accessible.error.message', { expectedText: expectedText, isNot, timeout });
+  }, expected, options);
+}
+
 export function toHaveAttribute(
   this: ExpectMatcherState,
   locator: LocatorEx,