diff --git a/apps/tests/layouts/layout-helper.d.ts b/apps/tests/layouts/layout-helper.d.ts
new file mode 100644
index 000000000..606fe7a95
--- /dev/null
+++ b/apps/tests/layouts/layout-helper.d.ts
@@ -0,0 +1,31 @@
+import button = require("ui/button");
+import {StackLayout} from "ui/layouts/stack-layout";
+
+export class MyButton extends button.Button {
+    public measureCount: number;
+    public arrangeCount: number;
+
+    measured: boolean;
+    arranged: boolean;
+
+    measureHeight: number;
+    measureWidth: number;
+    layoutWidth: number;
+    layoutHeight: number;
+    layoutLeft: number;
+    layoutTop: number;
+
+    _getCurrentMeasureSpecs(): { widthMeasureSpec: number; heightMeasureSpec: number };
+}
+
+export class MyStackLayout extends StackLayout {
+    public measureCount: number;
+    public arrangeCount: number;
+
+    public measured: boolean;
+    public arranged: boolean;
+}
+
+export function assertMeasure(btn: MyButton, width: number, height: number, name?: string);
+export function assertLayout(btn: MyButton, left: number, top: number, width: number, height: number, name?: string): void;
+export function dip(value: number): number;
\ No newline at end of file