1 files changed, 22 insertions, 0 deletions
diff --git a/spec/frontend/lib/utils/css_utils_spec.js b/spec/frontend/lib/utils/css_utils_spec.js
new file mode 100644
index 00000000000..dcaeb075c93
--- /dev/null
+++ b/spec/frontend/lib/utils/css_utils_spec.js
@@ -0,0 +1,22 @@
+import { getCssClassDimensions } from '~/lib/utils/css_utils';
+
+describe('getCssClassDimensions', () => {
+  const mockDimensions = { width: 1, height: 2 };
+  let actual;
+
+  beforeEach(() => {
+    jest.spyOn(Element.prototype, 'getBoundingClientRect').mockReturnValue(mockDimensions);
+    actual = getCssClassDimensions('foo bar');
+  });
+
+  it('returns the measured width and height', () => {
+    expect(actual).toEqual(mockDimensions);
+  });
+
+  it('measures an element with the given classes', () => {
+    expect(Element.prototype.getBoundingClientRect).toHaveBeenCalledTimes(1);
+
+    const [tempElement] = Element.prototype.getBoundingClientRect.mock.contexts;
+    expect([...tempElement.classList]).toEqual(['foo', 'bar']);
+  });
+});