Add basic test

Signed-off-by: Robin Murphy <robin@monzo.com>

packages/core/src/components/OverflowTooltip/OverflowTooltip.test.tsx

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import React from 'react';
+import { render } from '@testing-library/react';
+
+import { OverflowTooltip } from '.';
+
+describe('<OverflowTooltip />', () => {
+  it('renders without exploding', async () => {
+    render(<OverflowTooltip text="Text that may overflow" />);
+  });
+
+  it('renders without exploding when the text prop is missing', async () => {
+    render(<OverflowTooltip text={undefined} />);
+  });
+});