7 files changed, 88 insertions, 3 deletions
diff --git a/spec/frontend/helpers/experimentation_helper.js b/spec/frontend/helpers/experimentation_helper.js
new file mode 100644
index 00000000000..c08c25155e8
--- /dev/null
+++ b/spec/frontend/helpers/experimentation_helper.js
@@ -0,0 +1,14 @@
+import { merge } from 'lodash';
+
+export function withGonExperiment(experimentKey, value = true) {
+  let origGon;
+
+  beforeEach(() => {
+    origGon = window.gon;
+    window.gon = merge({}, window.gon || {}, { experiments: { [experimentKey]: value } });
+  });
+
+  afterEach(() => {
+    window.gon = origGon;
+  });
+}
diff --git a/spec/frontend/helpers/keep_alive_component_helper.js b/spec/frontend/helpers/keep_alive_component_helper.js
new file mode 100644
index 00000000000..54f40bf9093
--- /dev/null
+++ b/spec/frontend/helpers/keep_alive_component_helper.js
@@ -0,0 +1,29 @@
+import Vue from 'vue';
+
+export function keepAlive(KeptAliveComponent) {
+  return Vue.extend({
+    components: {
+      KeptAliveComponent,
+    },
+    data() {
+      return {
+        view: 'KeptAliveComponent',
+      };
+    },
+    methods: {
+      async activate() {
+        this.view = 'KeptAliveComponent';
+        await this.$nextTick();
+      },
+      async deactivate() {
+        this.view = 'div';
+        await this.$nextTick();
+      },
+      async reactivate() {
+        await this.deactivate();
+        await this.activate();
+      },
+    },
+    template: `<keep-alive><component :is="view"></component></keep-alive>`,
+  });
+}
diff --git a/spec/frontend/helpers/keep_alive_component_helper_spec.js b/spec/frontend/helpers/keep_alive_component_helper_spec.js
new file mode 100644
index 00000000000..dcccc14f396
--- /dev/null
+++ b/spec/frontend/helpers/keep_alive_component_helper_spec.js
@@ -0,0 +1,32 @@
+import { mount } from '@vue/test-utils';
+import { keepAlive } from './keep_alive_component_helper';
+
+const component = {
+  template: '<div>Test Component</div>',
+};
+
+describe('keepAlive', () => {
+  let wrapper;
+
+  beforeEach(() => {
+    wrapper = mount(keepAlive(component));
+  });
+
+  afterEach(() => {
+    wrapper.destroy();
+  });
+
+  it('converts a component to a keep-alive component', async () => {
+    const { element } = wrapper.find(component);
+
+    await wrapper.vm.deactivate();
+    expect(wrapper.find(component).exists()).toBe(false);
+
+    await wrapper.vm.activate();
+
+    // assert that when the component is destroyed and re-rendered, the
+    // newly rendered component has the reference to the old component
+    // (i.e. the old component was deactivated and activated)
+    expect(wrapper.find(component).element).toBe(element);
+  });
+});
diff --git a/spec/frontend/helpers/local_storage_helper.js b/spec/frontend/helpers/local_storage_helper.js
index cd39b660bfd..0318b80aaef 100644
--- a/spec/frontend/helpers/local_storage_helper.js
+++ b/spec/frontend/helpers/local_storage_helper.js
@@ -35,7 +35,7 @@ export const createLocalStorageSpy = () => {
     clear: jest.fn(() => {
       storage = {};
     }),
-    getItem: jest.fn(key => storage[key]),
+    getItem: jest.fn(key => (key in storage ? storage[key] : null)),
     setItem: jest.fn((key, value) => {
       storage[key] = value;
     }),
diff --git a/spec/frontend/helpers/local_storage_helper_spec.js b/spec/frontend/helpers/local_storage_helper_spec.js
index 6b44ea3a4c3..5d9961e7631 100644
--- a/spec/frontend/helpers/local_storage_helper_spec.js
+++ b/spec/frontend/helpers/local_storage_helper_spec.js
@@ -18,11 +18,11 @@ describe('localStorage helper', () => {
 
     localStorage.removeItem('test', 'testing');
 
-    expect(localStorage.getItem('test')).toBeUndefined();
+    expect(localStorage.getItem('test')).toBe(null);
     expect(localStorage.getItem('test2')).toBe('testing');
 
     localStorage.clear();
 
-    expect(localStorage.getItem('test2')).toBeUndefined();
+    expect(localStorage.getItem('test2')).toBe(null);
   });
 });
diff --git a/spec/frontend/helpers/vue_test_utils_helper.js b/spec/frontend/helpers/vue_test_utils_helper.js
index 68326e37ae7..ead898f04d3 100644
--- a/spec/frontend/helpers/vue_test_utils_helper.js
+++ b/spec/frontend/helpers/vue_test_utils_helper.js
@@ -33,3 +33,10 @@ export const waitForMutation = (store, expectedMutationType) =>
       }
     });
   });
+
+export const extendedWrapper = wrapper =>
+  Object.defineProperty(wrapper, 'findByTestId', {
+    value(id) {
+      return this.find(`[data-testid="${id}"]`);
+    },
+  });
diff --git a/spec/frontend/helpers/wait_for_text.js b/spec/frontend/helpers/wait_for_text.js
new file mode 100644
index 00000000000..6bed8a90a98
--- /dev/null
+++ b/spec/frontend/helpers/wait_for_text.js
@@ -0,0 +1,3 @@
+import { findByText } from '@testing-library/dom';
+
+export const waitForText = async (text, container = document) => findByText(container, text);