add test coverage for api notification mixin

__tests__/api/reusable.jsx

@@ -0,0 +1,34 @@
+// eslint-disable-next-line import/prefer-default-export
+export function describeNotificationMixin (Model, name) {
+  describe(name, () => {
+    const mockHttp = ({ post: jest.fn(() => Promise.resolve()) });
+    const ModelAPI = new Model(mockHttp);
+
+    afterEach(() => {
+      jest.clearAllMocks();
+    });
+
+    const parameters = [
+      ['success', true],
+      ['success', false],
+      ['error', true],
+      ['error', false],
+    ];
+    parameters.forEach(([type, state]) => {
+      const label = `[notificationType=${type}, associationState=${state}]`;
+      const testName = `updateNotificationTemplateAssociation ${label} makes expected http calls`;
+
+      test(testName, async (done) => {
+        await ModelAPI.updateNotificationTemplateAssociation(1, 21, type, state);
+
+        const expectedPath = `${ModelAPI.baseUrl}1/notification_templates_${type}/`;
+        expect(mockHttp.post).toHaveBeenCalledTimes(1);
+
+        const expectedParams = state ? { id: 21 } : { id: 21, disassociate: true };
+        expect(mockHttp.post.mock.calls.pop()).toEqual([expectedPath, expectedParams]);
+
+        done();
+      });
+    });
+  });
+}