test: add test case for findById

src/app/services/contact.service.spec.ts

@@ -43,6 +43,17 @@ describe('ContactService', () => {
     httpTestingController.verify();
   });
 
+  it('should GET contacts from the contacts ep with the given ID', () => {
+    const ID_MOCK = 1;
+    const url = `${endpointURL}/${ID_MOCK}`;
+    service.findById(String(ID_MOCK)).subscribe();
+    const req = httpTestingController.expectOne(url);
+    expect(req.request.method).toEqual('GET');
+    RES_MOCK.data = new ContactDTO(1, 'mock', 'mock', 'mock');
+    req.flush(RES_MOCK);
+    httpTestingController.verify();
+  });
+
   it('should POST contact to the contacts ep', () => {
     const CONTACT_MOCK = new ContactDTO(undefined, 'mock');
     service.save(CONTACT_MOCK).subscribe();