feat: use custom labels for block parent input labels

packages/blockly/core/block_aria_composer.ts

@@ -154,10 +154,24 @@ export function computeFieldRowLabel(
 }
 
 /**
- * Returns a description of the parent statement input a block is attached to.
- * When a block is connected to a statement input, the input's field row label
- * will be prepended to the block's description to indicate that the block
- * begins a clause in its parent block.
+ * Returns a description of the parent input a block is attached to.
+ * When a block is connected to an input, the input's label will sometimes
+ * be prepended to the block's description.
+ *
+ * If an input has a custom label, the custom label will be prepended
+ * to the first child block connected to that input.
+ *
+ * If an input does not have a custom label, the input's fallback
+ * label determined from the field row will be prepended to the
+ * child block's label only if the following are true:
+ * - the parent block has at least one statement input
+ * - the child block in question is not attached to the first
+ *   statement input of the parent block (in this case, the label
+ *   would be redundant with the parent block's label)
+ *
+ * For statement inputs, the resolved label (whether custom or fallback) is
+ * wrapped in the "Begin %1" prefix so the readout indicates that the child
+ * block starts the body of the statement input.
  *
  * @internal
  * @param block The block to generate a parent input label for.
@@ -168,24 +182,41 @@ function getParentInputLabel(block: BlockSvg) {
   const parentInput = (
     block.outputConnection ?? block.previousConnection
   )?.targetConnection?.getParentInput();
-  const parentBlock = parentInput?.getSourceBlock();
+  if (!parentInput) return undefined;
+
+  const parentBlock = parentInput.getSourceBlock();
+  if (parentBlock.isInsertionMarker()) return undefined;
+
+  // parentInput is only non-null when this block is directly attached to the
+  // input (i.e. it is the first child block in that input). A custom label
+  // is always prepended for the first child; a fallback label from the field
+  // row is only used in select circumstances.
+  let inputLabel: string | string[];
+  const customLabel = parentInput.getAriaLabelText();
+  if (customLabel) {
+    inputLabel = customLabel;
+  } else {
+    if (!parentBlock.statementInputCount) return undefined;
 
-  if (parentBlock?.isInsertionMarker()) return undefined;
-  if (!parentBlock?.statementInputCount) return undefined;
+    const firstStatementInput = parentBlock.inputList.find(
+      (i) => i.type === inputTypes.STATEMENT,
+    );
+    // The first statement input in a block has no field row label as it would
+    // be duplicative of the block's label.
+    if (parentInput === firstStatementInput) {
+      return undefined;
+    }
 
-  const firstStatementInput = parentBlock.inputList.find(
-    (i) => i.type === inputTypes.STATEMENT,
-  );
-  // The first statement input in a block has no field row label as it would
-  // be duplicative of the block's label.
-  if (!parentInput || parentInput === firstStatementInput) {
-    return undefined;
+    inputLabel = computeFieldRowLabel(parentInput, true);
   }
 
-  const parentInputLabel = computeFieldRowLabel(parentInput, true);
-  return parentInput.type === inputTypes.STATEMENT
-    ? Msg['BLOCK_LABEL_BEGIN_PREFIX'].replace('%1', parentInputLabel.join(' '))
-    : parentInputLabel;
+  if (parentInput.type === inputTypes.STATEMENT) {
+    const labelText = Array.isArray(inputLabel)
+      ? inputLabel.join(' ')
+      : inputLabel;
+    return Msg['BLOCK_LABEL_BEGIN_PREFIX'].replace('%1', labelText);
+  }
+  return inputLabel;
 }
 
 /**

packages/blockly/tests/mocha/aria_test.js

@@ -371,7 +371,7 @@ suite('ARIA', function () {
       assert.notInclude(label, 'Begin stack');
     });
 
-    test('Nested statement blocks in first statement input do not include their parent input in their label', function () {
+    test('Statement blocks in first statement input do not include their parent input in their label', function () {
       const ifBlock = this.makeBlock('controls_ifelse');
       const printBlock = this.makeBlock('text_print');
       ifBlock.getInput('IF0').connection.connect(printBlock.previousConnection);
@@ -382,7 +382,7 @@ suite('ARIA', function () {
       assert.isFalse(label.startsWith('Begin do'));
     });
 
-    test('Nested statement blocks in subsequent statement inputs include their parent input in their label', function () {
+    test('Statement blocks in subsequent statement inputs include their parent input in their label', function () {
       const ifBlock = this.makeBlock('controls_ifelse');
       const printBlock = this.makeBlock('text_print');
       ifBlock
@@ -395,6 +395,75 @@ suite('ARIA', function () {
       assert.isTrue(label.startsWith('Begin else'));
     });
 
+    test('A custom statement input label is wrapped in the "Begin" prefix', function () {
+      const ifBlock = this.makeBlock('controls_ifelse');
+      ifBlock.getInput('ELSE').setAriaLabelProvider('otherwise do');
+      const printBlock = this.makeBlock('text_print');
+      ifBlock
+        .getInput('ELSE')
+        .connection.connect(printBlock.previousConnection);
+      const label = Blockly.utils.aria.getState(
+        printBlock.getFocusableElement(),
+        Blockly.utils.aria.State.LABEL,
+      );
+      assert.include(label, 'Begin otherwise do');
+    });
+
+    test('A custom label on the first statement input is prepended to its child block label', function () {
+      const ifBlock = this.makeBlock('controls_ifelse');
+      ifBlock.getInput('DO0').setAriaLabelProvider('then do');
+      const printBlock = this.makeBlock('text_print');
+      ifBlock.getInput('DO0').connection.connect(printBlock.previousConnection);
+      const label = Blockly.utils.aria.getState(
+        printBlock.getFocusableElement(),
+        Blockly.utils.aria.State.LABEL,
+      );
+      assert.include(label, 'Begin then do');
+    });
+
+    test('A custom input label is only used for the first child block in a statement input stack', function () {
+      const ifBlock = this.makeBlock('controls_ifelse');
+      ifBlock.getInput('ELSE').setAriaLabelProvider('otherwise do');
+      const firstPrintBlock = this.makeBlock('text_print');
+      ifBlock
+        .getInput('ELSE')
+        .connection.connect(firstPrintBlock.previousConnection);
+      const secondPrintBlock = this.makeBlock('text_print');
+      firstPrintBlock.nextConnection.connect(
+        secondPrintBlock.previousConnection,
+      );
+      const subsequentLabel = Blockly.utils.aria.getState(
+        secondPrintBlock.getFocusableElement(),
+        Blockly.utils.aria.State.LABEL,
+      );
+      assert.notInclude(subsequentLabel, 'otherwise do');
+    });
+
+    test('A custom input label is prepended to the child block of a value input', function () {
+      const ifBlock = this.makeBlock('controls_ifelse');
+      ifBlock.getInput('IF0').setAriaLabelProvider('condition');
+      const boolBlock = this.makeBlock('logic_boolean');
+      ifBlock.getInput('IF0').connection.connect(boolBlock.outputConnection);
+      const label = Blockly.utils.aria.getState(
+        boolBlock.getFocusableElement(),
+        Blockly.utils.aria.State.LABEL,
+      );
+      assert.include(label, 'condition');
+    });
+
+    test('A block connected to a value input without a custom label does not include the input label', function () {
+      const negateBlock = this.makeBlock('logic_negate');
+      const boolBlock = this.makeBlock('logic_boolean');
+      negateBlock
+        .getInput('BOOL')
+        .connection.connect(boolBlock.outputConnection);
+      const label = Blockly.utils.aria.getState(
+        boolBlock.getFocusableElement(),
+        Blockly.utils.aria.State.LABEL,
+      );
+      assert.notInclude(label, 'not');
+    });
+
     test('Disabled blocks indicate that in their label', function () {
       const block = this.makeBlock('text_print');
       let label = Blockly.utils.aria.getState(