fix: Field text hidden from ARIA (#9734)

packages/blockly/core/field.ts

@@ -476,15 +476,18 @@ export abstract class Field<T = any>
   }
 
   /**
-   * Create a field text element. Not to be overridden by subclasses. Instead
+   * Create a field text element. Not to be overridden by subclasses. Instead,
    * modify the result of the function inside initView, or create a separate
-   * function to call.
+   * function to call. Aria state is hidden; use the aria label for the field
+   * and/or containing block to expose content to screen readers. Text content
+   * for custom blocks can be set after creation.
    */
   protected createTextElement_() {
     this.textElement_ = dom.createSvgElement(
       Svg.TEXT,
       {
         'class': 'blocklyText blocklyFieldText',
+        'aria-hidden': 'true',
       },
       this.fieldGroup_,
     );

packages/blockly/tests/mocha/field_test.js

@@ -944,5 +944,14 @@ suite('Abstract Fields', function () {
         assert.equal(field.computeAriaLabel(true), 'custom type: custom value');
       });
     });
+
+    suite('Field text elements are hidden', function () {
+      test('Field text element has aria-hidden=true', function () {
+        const field = new TestField();
+        field.constants_ = {FIELD_BORDER_RECT_RADIUS: 5};
+        field.initView();
+        assert(field.getTextElement().ariaHidden === 'true');
+      });
+    });
   });
 });