add custom icon btn test

client/src/components/__test__/customButton/CustomIconButton.spec.tsx

@@ -0,0 +1,28 @@
+import { fireEvent, render, screen } from '@testing-library/react';
+import CustomIconButton from '../../customButton/CustomIconButton';
+
+describe('test custom icon button component', () => {
+  it('renders default state', () => {
+    render(
+      <CustomIconButton>
+        <div className="icon">icon</div>
+      </CustomIconButton>
+    );
+
+    expect(screen.getByText('icon')).toHaveClass('icon');
+
+    const tooltip = screen.queryByText('tooltip');
+    expect(tooltip).toBeNull();
+  });
+
+  it('checks tooltip', async () => {
+    render(
+      <CustomIconButton tooltip="tooltip">
+        <div className="icon">icon</div>
+      </CustomIconButton>
+    );
+    // mock hover event
+    fireEvent.mouseOver(screen.getByText('icon'));
+    expect(await screen.findByText('tooltip')).toBeInTheDocument();
+  });
+});