type UpdateTestCase struct {
    inJSON   string
    inUpdate domain.User
    outJSON  string
    status   int
}

var testCaseUpdate = []UpdateTestCase{
    {
        inJSON: `{"email":"newmail1@mail.ru"}` + "\n",
        inUpdate: domain.User{
            ID:    1,
            Email: "newmail1@mail.ru",
        },
        outJSON: `{"id":1,"email":"newmail1@mail.ru","username":"good_user"}`,
        status:  http.StatusOK,
    },
    {
        inJSON: `{"username":"new_user1"}` + "\n",
        inUpdate: domain.User{
            ID:       1,
            Username: "new_user1",
        },
        outJSON: `{"id":1,"email":"mail1@mail.ru","username":"new_user1"}`,
        status:  http.StatusOK,
    },
    {
        inJSON: `{"email":"newmail1@mail.ru","username":"new_user1"}` + "\n",
        inUpdate: domain.User{
            ID:       1,
            Email:    "newmail1@mail.ru",
            Username: "new_user1",
        },
        outJSON: `{"id":1,"email":"newmail1@gmail.com","username":"new_user1"}`,
        status:  http.StatusOK,
    },
    {
        inJSON: `{"email":"","username":""}` + "\n",
        inUpdate: domain.User{
            ID:       1,
            Email:    "",
            Username: "",
        },
        outJSON: `{"message":"invalid update"}`,
        status:  http.StatusBadRequest,
    },
    {
        inJSON: `{}` + "\n",
        inUpdate: domain.User{
            ID: 1,
        },
        outJSON: `{"error":"error while updating user"}`,
        status:  http.StatusBadRequest,
    },
}

func TestUserHandler_Update(t *testing.T) {
    ctrl := gomock.NewController(t)
    defer ctrl.Finish()
    uCaseMock := mock.NewMockUserUsecase(ctrl)
    for _, test := range testCaseUpdate {
        if test.status == http.StatusOK {
            uCaseMock.EXPECT().Update(&test.inUpdate).Times(1).Return(nil)
            uCaseMock.EXPECT().GetById(uint(1)).Times(1).Return(usersTestData[1], nil)
        } else {
            uCaseMock.EXPECT().Update(test.inUpdate).Times(1).Return(user.InvalidUpdateError)
        }
    }
    handler := &UserHandler{
        UUsecase: uCaseMock,
    }
    for _, test := range testCaseUpdate {
        t.Run(fmt.Sprintf("IN: %v, OUT: %v, CODE: %v", test.inJSON, test.outJSON, test.status),
            func(t *testing.T) {
                test.outJSON += "\n"
                body := bytes.NewReader([]byte(test.inJSON))
                r := httptest.NewRequest("PATCH", "/api/users/1", body)
                r = mux.SetURLVars(r, map[string]string{"id": "1"})
                w := httptest.NewRecorder()

                err := session.Create(w, r, 1)
                require.NoError(t, err)
                defer session.Delete(w, r, 1)

                handler.Update(w, r)
                current := UpdateTestCase{
                    inJSON:   test.inJSON,
                    inUpdate: test.inUpdate,
                    outJSON:  w.Body.String(),
                    status:   w.Code,
                }
                require.Equal(t, test, current)
            })
    }
}