fix: LineCursor can loop forward, but not back (RaspberryPiFoundation#8926)

* fix: loop cursor when moving to prev node

* chore: add loop tests for LineCursor prev and out

* chore: fix out loop test for line cursor

Author: microbit-grace

core/keyboard_nav/line_cursor.ts

@@ -146,10 +146,12 @@ export class LineCursor extends Marker {
     if (!curNode) {
       return null;
     }
-    const newNode = this.getPreviousNodeImpl(
+    const newNode = this.getPreviousNode(
       curNode,
       this.validLineNode.bind(this),
+      true,
     );
+
     if (newNode) {
       this.setCurNode(newNode);
     }
@@ -168,9 +170,10 @@ export class LineCursor extends Marker {
     if (!curNode) {
       return null;
     }
-    const newNode = this.getPreviousNodeImpl(
+    const newNode = this.getPreviousNode(
       curNode,
       this.validInLineNode.bind(this),
+      true,
     );
 
     if (newNode) {

tests/mocha/cursor_test.js

@@ -125,6 +125,15 @@ suite('Cursor', function () {
       assert.equal(curNode.getLocation(), this.blocks.A.nextConnection);
     });
 
+    test('Prev - From first connection loop to last next connection', function () {
+      const prevConnection = this.blocks.A.previousConnection;
+      const prevConnectionNode = ASTNode.createConnectionNode(prevConnection);
+      this.cursor.setCurNode(prevConnectionNode);
+      this.cursor.prev();
+      const curNode = this.cursor.getCurNode();
+      assert.equal(curNode.getLocation(), this.blocks.D.nextConnection);
+    });
+
     test('Out - From field does not skip over block node', function () {
       const field = this.blocks.E.inputList[0].fieldRow[0];
       const fieldNode = ASTNode.createFieldNode(field);
@@ -133,6 +142,15 @@ suite('Cursor', function () {
       const curNode = this.cursor.getCurNode();
       assert.equal(curNode.getLocation(), this.blocks.E);
     });
+
+    test('Out - From first connection loop to last next connection', function () {
+      const prevConnection = this.blocks.A.previousConnection;
+      const prevConnectionNode = ASTNode.createConnectionNode(prevConnection);
+      this.cursor.setCurNode(prevConnectionNode);
+      this.cursor.out();
+      const curNode = this.cursor.getCurNode();
+      assert.equal(curNode.getLocation(), this.blocks.D.nextConnection);
+    });
   });
   suite('Searching', function () {
     setup(function () {