refactor(aria): refine grid state reset logic with dual-axis clamping and add tests

Author: tjshiu

src/aria/private/behaviors/grid/grid.spec.ts

@@ -395,7 +395,7 @@ describe('Grid', () => {
       expect(grid.focusBehavior.activeCoords()).toEqual({row: 1, col: 1});
     });
 
-    it('should focus the first cell if active cell and coords are no longer valid', () => {
+    it('should focus the row above when the last row is deleted', () => {
       const cellsSignal = signal(createTestGrid(createGridA));
       const grid = setupGrid(cellsSignal);
       grid.gotoCell(cellsSignal()[2][2]);
@@ -416,8 +416,8 @@ describe('Grid', () => {
       expect(grid.focusBehavior.stateStale()).toBe(true);
       const result = grid.resetState();
       expect(result).toBe(true);
-      expect(grid.focusBehavior.activeCell()).toBe(newCells[0][0]);
-      expect(grid.focusBehavior.activeCoords()).toEqual({row: 0, col: 0});
+      expect(grid.focusBehavior.activeCell()).toBe(newCells[1][1]);
+      expect(grid.focusBehavior.activeCoords()).toEqual({row: 1, col: 1});
     });
   });
 });

src/aria/private/behaviors/grid/grid.ts

@@ -342,6 +342,18 @@ export class Grid<T extends GridCell> {
           return true;
         }
 
+        // Try clamping the column as well.
+        const colCount = this.data.getColCount(targetRow);
+        if (colCount !== undefined) {
+          const targetCol = Math.min(activeCoords.col, colCount - 1);
+          if (
+            targetCol >= 0 &&
+            this.focusBehavior.focusCoordinates({row: targetRow, col: targetCol})
+          ) {
+            return true;
+          }
+        }
+
         // If that fails, try to find ANY cell in that row.
         const firstInRow = this.navigationBehavior.peekFirst(targetRow);
         if (firstInRow !== undefined && this.focusBehavior.focusCoordinates(firstInRow)) {