1 files changed, 40 insertions, 0 deletions
diff --git a/spec/frontend/ci/runner/local_storage_alert/show_alert_from_local_storage_spec.js b/spec/frontend/ci/runner/local_storage_alert/show_alert_from_local_storage_spec.js
new file mode 100644
index 00000000000..03908891cfd
--- /dev/null
+++ b/spec/frontend/ci/runner/local_storage_alert/show_alert_from_local_storage_spec.js
@@ -0,0 +1,40 @@
+import AccessorUtilities from '~/lib/utils/accessor';
+import { showAlertFromLocalStorage } from '~/ci/runner/local_storage_alert/show_alert_from_local_storage';
+import { LOCAL_STORAGE_ALERT_KEY } from '~/ci/runner/local_storage_alert/constants';
+import { useLocalStorageSpy } from 'helpers/local_storage_helper';
+import { createAlert } from '~/flash';
+
+jest.mock('~/flash');
+
+describe('showAlertFromLocalStorage', () => {
+  useLocalStorageSpy();
+
+  beforeEach(() => {
+    jest.spyOn(AccessorUtilities, 'canUseLocalStorage').mockReturnValue(true);
+  });
+
+  it('retrieves message from local storage and displays it', async () => {
+    const mockAlert = { message: 'Message!' };
+
+    localStorage.getItem.mockReturnValueOnce(JSON.stringify(mockAlert));
+
+    await showAlertFromLocalStorage();
+
+    expect(createAlert).toHaveBeenCalledTimes(1);
+    expect(createAlert).toHaveBeenCalledWith(mockAlert);
+
+    expect(localStorage.removeItem).toHaveBeenCalledTimes(1);
+    expect(localStorage.removeItem).toHaveBeenCalledWith(LOCAL_STORAGE_ALERT_KEY);
+  });
+
+  it.each(['not a json string', null])('does not fail when stored message is %o', async (item) => {
+    localStorage.getItem.mockReturnValueOnce(item);
+
+    await showAlertFromLocalStorage();
+
+    expect(createAlert).not.toHaveBeenCalled();
+
+    expect(localStorage.removeItem).toHaveBeenCalledTimes(1);
+    expect(localStorage.removeItem).toHaveBeenCalledWith(LOCAL_STORAGE_ALERT_KEY);
+  });
+});