fix(textarea): ensure screen readers announce helper and error text when focused

Author: thetaPC

core/src/components/textarea/test/bottom-content/textarea.e2e.ts

@@ -27,6 +27,19 @@ configs({ modes: ['md'], directions: ['ltr'] }).forEach(({ title, screenshot, co
         await expect(helperText).toHaveText('my helper');
         await expect(errorText).toBeHidden();
       });
+      test('textarea should have an aria-describedby attribute when helper text is present', async ({ page }) => {
+        await page.setContent(
+          `<ion-textarea helper-text="my helper" error-text="my error" label="my textarea"></ion-textarea>`,
+          config
+        );
+
+        const textarea = page.locator('ion-textarea textarea');
+        const helperText = page.locator('ion-textarea .helper-text');
+        const helperTextId = await helperText.getAttribute('id');
+        const ariaDescribedBy = await textarea.getAttribute('aria-describedby');
+
+        expect(ariaDescribedBy).toBe(helperTextId);
+      });
       test('error text should be visible when textarea is invalid', async ({ page }) => {
         await page.setContent(
           `<ion-textarea class="ion-invalid ion-touched" helper-text="my helper" error-text="my error" label="my textarea"></ion-textarea>`,
@@ -55,6 +68,48 @@ configs({ modes: ['md'], directions: ['ltr'] }).forEach(({ title, screenshot, co
         const errorText = page.locator('ion-textarea .error-text');
         await expect(errorText).toHaveScreenshot(screenshot(`textarea-error-custom-color`));
       });
+      test('textarea should have an aria-describedby attribute when error text is present', async ({ page }) => {
+        await page.setContent(
+          `<ion-textarea class="ion-invalid ion-touched" helper-text="my helper" error-text="my error" label="my textarea"></ion-textarea>`,
+          config
+        );
+
+        const textarea = page.locator('ion-textarea textarea');
+        const errorText = page.locator('ion-textarea .error-text');
+        const errorTextId = await errorText.getAttribute('id');
+        const ariaDescribedBy = await textarea.getAttribute('aria-describedby');
+
+        expect(ariaDescribedBy).toBe(errorTextId);
+      });
+      test('textarea should have aria-invalid attribute when input is invalid', async ({ page }) => {
+        await page.setContent(
+          `<ion-textarea class="ion-invalid ion-touched" helper-text="my helper" error-text="my error" label="my textarea"></ion-textarea>`,
+          config
+        );
+
+        const textarea = page.locator('ion-textarea textarea');
+
+        await expect(textarea).toHaveAttribute('aria-invalid');
+      });
+      test('textarea should not have aria-invalid attribute when input is valid', async ({ page }) => {
+        await page.setContent(
+          `<ion-textarea helper-text="my helper" error-text="my error" label="my textarea"></ion-textarea>`,
+          config
+        );
+
+        const textarea = page.locator('ion-textarea textarea');
+
+        await expect(textarea).not.toHaveAttribute('aria-invalid');
+      });
+      test('textarea should not have aria-describedby attribute when no hint or error text is present', async ({
+        page,
+      }) => {
+        await page.setContent(`<ion-textarea label="my textarea"></ion-textarea>`, config);
+
+        const textarea = page.locator('ion-textarea textarea');
+
+        await expect(textarea).not.toHaveAttribute('aria-describedby');
+      });
     });
     test.describe('textarea: hint text rendering', () => {
       test.describe('regular textareas', () => {

core/src/components/textarea/textarea.tsx

@@ -45,6 +45,8 @@ import type { TextareaChangeEventDetail, TextareaInputEventDetail } from './text
 export class Textarea implements ComponentInterface {
   private nativeInput?: HTMLTextAreaElement;
   private inputId = `ion-textarea-${textareaIds++}`;
+  private helperTextId = `helper-text-${textareaIds++}`;
+  private errorTextId = `error-text-${textareaIds++}`;
   /**
    * `true` if the textarea was cleared as a result of the user typing
    * with `clearOnEdit` enabled.
@@ -576,9 +578,30 @@ export class Textarea implements ComponentInterface {
    * Renders the helper text or error text values
    */
   private renderHintText() {
-    const { helperText, errorText } = this;
+    const { helperText, errorText, helperTextId, errorTextId } = this;
+
+    return [
+      <div id={helperTextId} class="helper-text">
+        {helperText}
+      </div>,
+      <div id={errorTextId} class="error-text">
+        {errorText}
+      </div>,
+    ];
+  }
+
+  private getHintTextID(): string | undefined {
+    const { el, helperText, errorText, helperTextId, errorTextId } = this;
+
+    if (el.classList.contains('ion-touched') && el.classList.contains('ion-invalid') && errorText) {
+      return errorTextId;
+    }
+
+    if (helperText) {
+      return helperTextId;
+    }
 
-    return [<div class="helper-text">{helperText}</div>, <div class="error-text">{errorText}</div>];
+    return undefined;
   }
 
   private renderCounter() {
@@ -703,6 +726,8 @@ export class Textarea implements ComponentInterface {
                 onBlur={this.onBlur}
                 onFocus={this.onFocus}
                 onKeyDown={this.onKeyDown}
+                aria-describedby={this.getHintTextID()}
+                aria-invalid={this.getHintTextID() === this.errorTextId}
                 {...this.inheritedAttributes}
               >
                 {value}