Fix AbstractRow rowheaders/columnheaders no-op concat

src/ui-kit/experimental/aria/abstract-grid/abstract-row.spec.ts

@@ -35,6 +35,36 @@ describe("AbstractRow", () => {
     ]);
   });
 
+  it("populates rowheaders and columnheaders with their respective cells", () => {
+    const row = buildRow([
+      { role: "columnheader", key: "col" },
+      { role: "rowheader", key: "row" },
+      { role: "gridcell", key: "a" },
+      { role: "gridcell", key: "b" },
+    ]);
+
+    const abstractRow = new AbstractRow(row);
+
+    expect(abstractRow.rowheaders.map((c) => c.key)).toEqual(["row"]);
+    expect(abstractRow.columnheaders.map((c) => c.key)).toEqual(["col"]);
+  });
+
+  it("reuses the same AbstractCell instances in rowheaders/columnheaders as in cells", () => {
+    const row = buildRow([
+      { role: "columnheader", key: "col" },
+      { role: "rowheader", key: "row" },
+      { role: "gridcell", key: "a" },
+    ]);
+
+    const abstractRow = new AbstractRow(row);
+
+    const rowheaderInCells = abstractRow.cells.find((c) => c.key === "row");
+    const columnheaderInCells = abstractRow.cells.find((c) => c.key === "col");
+
+    expect(abstractRow.rowheaders[0]).toBe(rowheaderInCells);
+    expect(abstractRow.columnheaders[0]).toBe(columnheaderInCells);
+  });
+
   it("addCell appends a cell to the cells collection", () => {
     const row = buildRow([{ role: "gridcell", key: "a" }]);
     const abstractRow = new AbstractRow(row);

src/ui-kit/experimental/aria/abstract-grid/abstract-row.ts

@@ -24,7 +24,7 @@ export class AbstractRow {
 
       this._setRowHeaders(cells, role);
 
-      return accumulator.concat(this._getCellsByRole(node, role));
+      return accumulator.concat(cells);
     }, []);
   }
 
@@ -43,9 +43,9 @@ export class AbstractRow {
 
   private _setRowHeaders(cells: AbstractCell[], role: CellRole): void {
     if (role === "rowheader") {
-      this.rowheaders.concat(cells);
+      this.rowheaders = this.rowheaders.concat(cells);
     } else if (role === "columnheader") {
-      this.columnheaders.concat(cells);
+      this.columnheaders = this.columnheaders.concat(cells);
     } else {
       return;
     }