Move ajax_cache_spec.js to Jest

1 files changed, 161 insertions, 0 deletions

diff --git a/spec/frontend/lib/utils/ajax_cache_spec.js b/spec/frontend/lib/utils/ajax_cache_spec.js
new file mode 100644
index 00000000000..e2ee70b9d69
--- /dev/null
+++ b/spec/frontend/lib/utils/ajax_cache_spec.js
@@ -0,0 +1,161 @@
+import MockAdapter from 'axios-mock-adapter';
+import axios from '~/lib/utils/axios_utils';
+import AjaxCache from '~/lib/utils/ajax_cache';
+
+describe('AjaxCache', () => {
+  const dummyEndpoint = '/AjaxCache/dummyEndpoint';
+  const dummyResponse = {
+    important: 'dummy data',
+  };
+
+  beforeEach(() => {
+    AjaxCache.internalStorage = {};
+    AjaxCache.pendingRequests = {};
+  });
+
+  describe('get', () => {
+    it('returns undefined if cache is empty', () => {
+      const data = AjaxCache.get(dummyEndpoint);
+
+      expect(data).toBe(undefined);
+    });
+
+    it('returns undefined if cache contains no matching data', () => {
+      AjaxCache.internalStorage['not matching'] = dummyResponse;
+
+      const data = AjaxCache.get(dummyEndpoint);
+
+      expect(data).toBe(undefined);
+    });
+
+    it('returns matching data', () => {
+      AjaxCache.internalStorage[dummyEndpoint] = dummyResponse;
+
+      const data = AjaxCache.get(dummyEndpoint);
+
+      expect(data).toBe(dummyResponse);
+    });
+  });
+
+  describe('hasData', () => {
+    it('returns false if cache is empty', () => {
+      expect(AjaxCache.hasData(dummyEndpoint)).toBe(false);
+    });
+
+    it('returns false if cache contains no matching data', () => {
+      AjaxCache.internalStorage['not matching'] = dummyResponse;
+
+      expect(AjaxCache.hasData(dummyEndpoint)).toBe(false);
+    });
+
+    it('returns true if data is available', () => {
+      AjaxCache.internalStorage[dummyEndpoint] = dummyResponse;
+
+      expect(AjaxCache.hasData(dummyEndpoint)).toBe(true);
+    });
+  });
+
+  describe('remove', () => {
+    it('does nothing if cache is empty', () => {
+      AjaxCache.remove(dummyEndpoint);
+
+      expect(AjaxCache.internalStorage).toEqual({});
+    });
+
+    it('does nothing if cache contains no matching data', () => {
+      AjaxCache.internalStorage['not matching'] = dummyResponse;
+
+      AjaxCache.remove(dummyEndpoint);
+
+      expect(AjaxCache.internalStorage['not matching']).toBe(dummyResponse);
+    });
+
+    it('removes matching data', () => {
+      AjaxCache.internalStorage[dummyEndpoint] = dummyResponse;
+
+      AjaxCache.remove(dummyEndpoint);
+
+      expect(AjaxCache.internalStorage).toEqual({});
+    });
+  });
+
+  describe('override', () => {
+    it('overrides existing cache', () => {
+      AjaxCache.internalStorage.endpoint = 'existing-endpoint';
+      AjaxCache.override('endpoint', 'new-endpoint');
+
+      expect(AjaxCache.internalStorage.endpoint).toEqual('new-endpoint');
+    });
+  });
+
+  describe('retrieve', () => {
+    let mock;
+
+    beforeEach(() => {
+      mock = new MockAdapter(axios);
+
+      jest.spyOn(axios, 'get');
+    });
+
+    afterEach(() => {
+      mock.restore();
+    });
+
+    it('stores and returns data from Ajax call if cache is empty', () => {
+      mock.onGet(dummyEndpoint).reply(200, dummyResponse);
+
+      return AjaxCache.retrieve(dummyEndpoint).then(data => {
+        expect(data).toEqual(dummyResponse);
+        expect(AjaxCache.internalStorage[dummyEndpoint]).toEqual(dummyResponse);
+      });
+    });
+
+    it('makes no Ajax call if request is pending', () => {
+      mock.onGet(dummyEndpoint).reply(200, dummyResponse);
+
+      return Promise.all([
+        AjaxCache.retrieve(dummyEndpoint),
+        AjaxCache.retrieve(dummyEndpoint),
+      ]).then(() => {
+        expect(axios.get).toHaveBeenCalledTimes(1);
+      });
+    });
+
+    it('returns undefined if Ajax call fails and cache is empty', () => {
+      const errorMessage = 'Network Error';
+      mock.onGet(dummyEndpoint).networkError();
+
+      expect.assertions(2);
+      return AjaxCache.retrieve(dummyEndpoint).catch(error => {
+        expect(error.message).toBe(`${dummyEndpoint}: ${errorMessage}`);
+        expect(error.textStatus).toBe(errorMessage);
+      });
+    });
+
+    it('makes no Ajax call if matching data exists', () => {
+      AjaxCache.internalStorage[dummyEndpoint] = dummyResponse;
+
+      return AjaxCache.retrieve(dummyEndpoint).then(data => {
+        expect(data).toBe(dummyResponse);
+        expect(axios.get).not.toHaveBeenCalled();
+      });
+    });
+
+    it('makes Ajax call even if matching data exists when forceRequest parameter is provided', () => {
+      const oldDummyResponse = {
+        important: 'old dummy data',
+      };
+
+      AjaxCache.internalStorage[dummyEndpoint] = oldDummyResponse;
+
+      mock.onGet(dummyEndpoint).reply(200, dummyResponse);
+
+      return Promise.all([
+        AjaxCache.retrieve(dummyEndpoint),
+        AjaxCache.retrieve(dummyEndpoint, true),
+      ]).then(data => {
+        expect(data).toEqual([oldDummyResponse, dummyResponse]);
+      });
+    });
+  });
+});