preparations for isolated TS modules

plugins/identity-backend/src/index.test.ts

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+import '@backstage/backend-common';
+
 describe('test', () => {
   it('unbreaks the test runner', () => {
     expect(true).toBeTruthy();

plugins/identity-backend/src/setupTests.ts

@@ -15,3 +15,4 @@
  */
 
 require('jest-fetch-mock').enableMocks();
+export {};