diff --git a/src/components/map/Handlers.test.tsx b/src/components/map/Handlers.test.tsx
index 343aa2f..8f32817 100644
--- a/src/components/map/Handlers.test.tsx
+++ b/src/components/map/Handlers.test.tsx
@@ -150,4 +150,97 @@ Arguments [
     // screen.debug();
     expect(transformMapParams).toBeUndefined();
   });
+
+  test('throttle mouseMove events', () => {
+    var transformMapParams: any;
+    function transformMap(
+      deltaShift: Point | null,
+      deltaZoom: number | null,
+      zoomCenter: Point | null
+    ) {
+      console.log(`transformMap${JSON.stringify(arguments)}`);
+      transformMapParams = arguments;
+    }
+    render(<Handlers transformMap={transformMap} />);
+    const handlers = screen.getByRole('presentation');
+    fireEvent(
+      handlers,
+      createEvent.mouseDown(handlers, {
+        clientX: 10,
+        clientY: 20,
+      })
+    );
+    fireEvent(
+      handlers,
+      createEvent.mouseMove(handlers, {
+        clientX: 20,
+        clientY: 50,
+      })
+    );
+    fireEvent(
+      handlers,
+      createEvent.mouseMove(handlers, {
+        clientX: 30,
+        clientY: 60,
+      })
+    );
+    // screen.debug();
+    expect(transformMapParams).toMatchInlineSnapshot(`
+Arguments [
+  Object {
+    "x": 10,
+    "y": 30,
+  },
+  null,
+  null,
+]
+`);
+  });
+
+  test('throttle mouseMove events', async () => {
+    var transformMapParams: any;
+    function transformMap(
+      deltaShift: Point | null,
+      deltaZoom: number | null,
+      zoomCenter: Point | null
+    ) {
+      console.log(`transformMap${JSON.stringify(arguments)}`);
+      transformMapParams = arguments;
+    }
+    render(<Handlers transformMap={transformMap} />);
+    const handlers = screen.getByRole('presentation');
+    fireEvent(
+      handlers,
+      createEvent.mouseDown(handlers, {
+        clientX: 10,
+        clientY: 20,
+      })
+    );
+    fireEvent(
+      handlers,
+      createEvent.mouseMove(handlers, {
+        clientX: 20,
+        clientY: 50,
+      })
+    );
+    await new Promise((r) => setTimeout(r, 500));
+    fireEvent(
+      handlers,
+      createEvent.mouseMove(handlers, {
+        clientX: 5,
+        clientY: 5,
+      })
+    );
+    // screen.debug();
+    expect(transformMapParams).toMatchInlineSnapshot(`
+Arguments [
+  Object {
+    "x": -15,
+    "y": -45,
+  },
+  null,
+  null,
+]
+`);
+  });
 });