fix mock ChartClient

add comments

superset-frontend/spec/helpers/setupSupersetClient.js

@@ -17,7 +17,9 @@
  * under the License.
  */
 import fetchMock from 'fetch-mock';
-import { SupersetClient } from '@superset-ui/core';
+// https://jestjs.io/docs/jest-object#jestmockmodulename-factory-options
+// in order to mock modules in test case, so avoid absolute import module
+import { SupersetClient } from '../../packages/superset-ui-core/src/connection';
 
 export default function setupSupersetClient() {
   // The following is needed to mock out SupersetClient requests

superset-frontend/spec/helpers/shim.ts

@@ -23,10 +23,13 @@ import 'jest-enzyme';
 import jQuery from 'jquery';
 import { configure } from 'enzyme';
 import Adapter from 'enzyme-adapter-react-16';
-import { configure as configureTranslation } from '@superset-ui/core';
+// https://jestjs.io/docs/jest-object#jestmockmodulename-factory-options
+// in order to mock modules in test case, so avoid absolute import module
+import { configure as configureTranslation } from '../../packages/superset-ui-core/src/translation';
 import { Worker } from './Worker';
 import { IntersectionObserver } from './IntersectionObserver';
 import setupSupersetClient from './setupSupersetClient';
+import CacheStorage from './CacheStorage';
 
 configure({ adapter: new Adapter() });
 
@@ -49,6 +52,7 @@ g.window.performance = { now: () => new Date().getTime() };
 g.window.Worker = Worker;
 g.window.IntersectionObserver = IntersectionObserver;
 g.URL.createObjectURL = () => '';
+g.caches = new CacheStorage();
 
 Object.defineProperty(window, 'matchMedia', {
   writable: true,