Merge pull request #202 from android10/generic-use-cases

Generic use cases

data/src/test/java/com/fernandocejas/android10/sample/data/repository/UserDataRepositoryTest.java

@@ -24,9 +24,7 @@ import io.reactivex.Observable;
 import java.util.ArrayList;
 import java.util.List;
 import org.junit.Before;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
@@ -48,14 +46,9 @@ public class UserDataRepositoryTest {
   @Mock private UserEntity mockUserEntity;
   @Mock private User mockUser;
 
-  @Rule
-  public ExpectedException expectedException = ExpectedException.none();
-
   @Before
   public void setUp() {
-    userDataRepository = new UserDataRepository(mockUserDataStoreFactory,
-        mockUserEntityDataMapper);
-
+    userDataRepository = new UserDataRepository(mockUserDataStoreFactory, mockUserEntityDataMapper);
     given(mockUserDataStoreFactory.create(anyInt())).willReturn(mockUserDataStore);
     given(mockUserDataStoreFactory.createCloudDataStore()).willReturn(mockUserDataStore);
   }

domain/src/main/java/com/fernandocejas/android10/sample/domain/interactor/GetUserDetails.java

@@ -19,8 +19,7 @@ import com.fernandocejas.android10.sample.domain.User;
 import com.fernandocejas.android10.sample.domain.executor.PostExecutionThread;
 import com.fernandocejas.android10.sample.domain.executor.ThreadExecutor;
 import com.fernandocejas.android10.sample.domain.repository.UserRepository;
-import com.fernandocejas.arrow.annotations.VisibleForTesting;
-import com.fernandocejas.arrow.optional.Optional;
+import com.fernandocejas.arrow.checks.Preconditions;
 import io.reactivex.Observable;
 import javax.inject.Inject;
 
@@ -28,29 +27,32 @@ import javax.inject.Inject;
  * This class is an implementation of {@link UseCase} that represents a use case for
  * retrieving data related to an specific {@link User}.
  */
-public class GetUserDetails extends UseCase {
-
-  public static final String NAME = "userDetails";
-  public static final String PARAM_USER_ID_KEY = "userId";
-
-  @VisibleForTesting
-  static final int PARAM_USER_ID_DEFAULT_VALUE = -1;
+public class GetUserDetails extends UseCase<User, GetUserDetails.Params> {
 
   private final UserRepository userRepository;
 
   @Inject
-  public GetUserDetails(UserRepository userRepository, ThreadExecutor threadExecutor,
+  GetUserDetails(UserRepository userRepository, ThreadExecutor threadExecutor,
       PostExecutionThread postExecutionThread) {
     super(threadExecutor, postExecutionThread);
     this.userRepository = userRepository;
   }
 
-  @Override protected Observable buildUseCaseObservable(Optional<Params> params) {
-    if (params.isPresent()) {
-      final int userId = params.get().getInt(PARAM_USER_ID_KEY, PARAM_USER_ID_DEFAULT_VALUE);
-      return this.userRepository.user(userId);
-    } else {
-      return Observable.empty();
+  @Override Observable<User> buildUseCaseObservable(Params params) {
+    Preconditions.checkNotNull(params);
+    return this.userRepository.user(params.userId);
+  }
+
+  public static final class Params {
+
+    private final int userId;
+
+    private Params(int userId) {
+      this.userId = userId;
+    }
+
+    public static Params forUser(int userId) {
+      return new Params(userId);
     }
   }
 }

domain/src/main/java/com/fernandocejas/android10/sample/domain/interactor/GetUserList.java

@@ -19,17 +19,15 @@ import com.fernandocejas.android10.sample.domain.User;
 import com.fernandocejas.android10.sample.domain.executor.PostExecutionThread;
 import com.fernandocejas.android10.sample.domain.executor.ThreadExecutor;
 import com.fernandocejas.android10.sample.domain.repository.UserRepository;
-import com.fernandocejas.arrow.optional.Optional;
 import io.reactivex.Observable;
+import java.util.List;
 import javax.inject.Inject;
 
 /**
  * This class is an implementation of {@link UseCase} that represents a use case for
  * retrieving a collection of all {@link User}.
  */
-public class GetUserList extends UseCase {
-
-  public static final String NAME = "userList";
+public class GetUserList extends UseCase<List<User>, Void> {
 
   private final UserRepository userRepository;
 
@@ -40,7 +38,7 @@ public class GetUserList extends UseCase {
     this.userRepository = userRepository;
   }
 
-  @Override public Observable buildUseCaseObservable(Optional<Params> params) {
+  @Override Observable<List<User>> buildUseCaseObservable(Void unused) {
     return this.userRepository.users();
   }
 }

domain/src/main/java/com/fernandocejas/android10/sample/domain/interactor/Params.java

@@ -1,50 +0,0 @@
-/**
- * Copyright (C) 2016 Fernando Cejas Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.fernandocejas.android10.sample.domain.interactor;
-
-import java.util.HashMap;
-import java.util.Map;
-
-/**
- * Class backed by a Map, used to pass parameters to {@link UseCase} instances.
- */
-public final class Params {
-  public static final Params EMPTY = Params.create();
-
-  private final Map<String, Object> parameters = new HashMap<>();
-
-  private Params() {}
-
-  public static Params create() {
-    return new Params();
-  }
-
-  public void putInt(String key, int value) {
-    parameters.put(key, value);
-  }
-
-  int getInt(String key, int defaultValue) {
-    final Object object = parameters.get(key);
-    if (object == null) {
-      return defaultValue;
-    }
-    try {
-      return (int) object;
-    } catch (ClassCastException e) {
-      return defaultValue;
-    }
-  }
-}

domain/src/main/java/com/fernandocejas/android10/sample/domain/interactor/UseCase.java

@@ -18,7 +18,6 @@ package com.fernandocejas.android10.sample.domain.interactor;
 import com.fernandocejas.android10.sample.domain.executor.PostExecutionThread;
 import com.fernandocejas.android10.sample.domain.executor.ThreadExecutor;
 import com.fernandocejas.arrow.checks.Preconditions;
-import com.fernandocejas.arrow.optional.Optional;
 import io.reactivex.Observable;
 import io.reactivex.disposables.CompositeDisposable;
 import io.reactivex.disposables.Disposable;
@@ -33,7 +32,7 @@ import io.reactivex.schedulers.Schedulers;
  * By convention each UseCase implementation will return the result using a {@link DisposableObserver}
  * that will execute its job in a background thread and will post the result in the UI thread.
  */
-public abstract class UseCase {
+public abstract class UseCase<T, Params> {
 
   private final ThreadExecutor threadExecutor;
   private final PostExecutionThread postExecutionThread;
@@ -48,18 +47,18 @@ public abstract class UseCase {
   /**
    * Builds an {@link Observable} which will be used when executing the current {@link UseCase}.
    */
-  protected abstract Observable buildUseCaseObservable(Optional<Params> params);
+  abstract Observable<T> buildUseCaseObservable(Params params);
 
   /**
    * Executes the current use case.
    *
    * @param observer {@link DisposableObserver} which will be listening to the observable build
-   * by {@link #buildUseCaseObservable(Optional)} ()} method.
-   * @param params Parameters used to build execute this use case.
+   * by {@link #buildUseCaseObservable(Params)} ()} method.
+   * @param params Parameters (Optional) used to build/execute this use case.
    */
-  @SuppressWarnings("unchecked")
-  public void execute(DisposableObserver observer, Params params) {
-    final Observable<?> observable = this.buildUseCaseObservable(Optional.of(params))
+  public void execute(DisposableObserver<T> observer, Params params) {
+    Preconditions.checkNotNull(observer);
+    final Observable<T> observable = this.buildUseCaseObservable(params)
         .subscribeOn(Schedulers.from(threadExecutor))
         .observeOn(postExecutionThread.getScheduler());
     addDisposable(observable.subscribeWith(observer));

domain/src/test/java/com/fernandocejas/android10/sample/domain/interactor/GetUserDetailsTest.java

@@ -17,16 +17,16 @@ package com.fernandocejas.android10.sample.domain.interactor;
 
 import com.fernandocejas.android10.sample.domain.executor.PostExecutionThread;
 import com.fernandocejas.android10.sample.domain.executor.ThreadExecutor;
+import com.fernandocejas.android10.sample.domain.interactor.GetUserDetails.Params;
 import com.fernandocejas.android10.sample.domain.repository.UserRepository;
-import com.fernandocejas.arrow.optional.Optional;
-import io.reactivex.Observable;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
 
-import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.verifyZeroInteractions;
@@ -42,6 +42,8 @@ public class GetUserDetailsTest {
   @Mock private ThreadExecutor mockThreadExecutor;
   @Mock private PostExecutionThread mockPostExecutionThread;
 
+  @Rule public ExpectedException expectedException = ExpectedException.none();
+
   @Before
   public void setUp() {
     getUserDetails = new GetUserDetails(mockUserRepository, mockThreadExecutor,
@@ -50,10 +52,7 @@ public class GetUserDetailsTest {
 
   @Test
   public void testGetUserDetailsUseCaseObservableHappyCase() {
-    final Params params = Params.create();
-    params.putInt(GetUserDetails.PARAM_USER_ID_KEY, USER_ID);
-
-    getUserDetails.buildUseCaseObservable(Optional.of(params));
+    getUserDetails.buildUseCaseObservable(Params.forUser(USER_ID));
 
     verify(mockUserRepository).user(USER_ID);
     verifyNoMoreInteractions(mockUserRepository);
@@ -62,22 +61,8 @@ public class GetUserDetailsTest {
   }
 
   @Test
-  public void testShouldReturnEmptyObservableWhenNoParameters() {
-    final Observable observable = getUserDetails.buildUseCaseObservable(Optional.<Params>absent());
-
-    assertThat(observable).isEqualTo(Observable.empty());
-    verifyZeroInteractions(mockUserRepository);
-    verifyZeroInteractions(mockPostExecutionThread);
-    verifyZeroInteractions(mockThreadExecutor);
-  }
-
-  @Test
-  public void testShouldUseDefaultUserIdValueWhenNoUserIdParameter() {
-    getUserDetails.buildUseCaseObservable(Optional.of(Params.create()));
-
-    verify(mockUserRepository).user(GetUserDetails.PARAM_USER_ID_DEFAULT_VALUE);
-    verifyNoMoreInteractions(mockUserRepository);
-    verifyZeroInteractions(mockPostExecutionThread);
-    verifyZeroInteractions(mockThreadExecutor);
+  public void testShouldFailWhenNoOrEmptyParameters() {
+    expectedException.expect(NullPointerException.class);
+    getUserDetails.buildUseCaseObservable(null);
   }
 }

domain/src/test/java/com/fernandocejas/android10/sample/domain/interactor/GetUserListTest.java

@@ -18,14 +18,12 @@ package com.fernandocejas.android10.sample.domain.interactor;
 import com.fernandocejas.android10.sample.domain.executor.PostExecutionThread;
 import com.fernandocejas.android10.sample.domain.executor.ThreadExecutor;
 import com.fernandocejas.android10.sample.domain.repository.UserRepository;
-import com.fernandocejas.arrow.optional.Optional;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
 
-import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.verifyZeroInteractions;
@@ -47,22 +45,11 @@ public class GetUserListTest {
 
   @Test
   public void testGetUserListUseCaseObservableHappyCase() {
-    getUserList.buildUseCaseObservable(Optional.of(Params.EMPTY));
+    getUserList.buildUseCaseObservable(null);
 
     verify(mockUserRepository).users();
     verifyNoMoreInteractions(mockUserRepository);
     verifyZeroInteractions(mockThreadExecutor);
     verifyZeroInteractions(mockPostExecutionThread);
   }
-
-  @Test
-  @SuppressWarnings("unchecked")
-  public void testThereShouldNotBeAnyInteractionWithParams() {
-    Optional params = mock(Optional.class);
-
-    getUserList.buildUseCaseObservable(params);
-
-    verify(mockUserRepository).users();
-    verifyZeroInteractions(params);
-  }
 }

domain/src/test/java/com/fernandocejas/android10/sample/domain/interactor/ParamsTest.java

@@ -1,49 +0,0 @@
-/**
- * Copyright (C) 2016 Fernando Cejas Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.fernandocejas.android10.sample.domain.interactor;
-
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.mockito.runners.MockitoJUnitRunner;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
-@RunWith(MockitoJUnitRunner.class)
-public class ParamsTest {
-
-  private Params params;
-
-  @Before
-  public void setUp() {
-    params = Params.create();
-  }
-
-  @Test
-  public void testShouldReturnIntValue() {
-    params.putInt("key01", 3);
-
-    assertThat(params.getInt("key01", 5)).isEqualTo(3);
-  }
-
-  @Test
-  public void testShouldReturnIntDefaultValue() {
-    params.putInt("key01", 3);
-    params.putInt("key02", 4);
-
-    assertThat(params.getInt("key03", 5)).isEqualTo(5);
-  }
-}

domain/src/test/java/com/fernandocejas/android10/sample/domain/interactor/UseCaseTest.java

@@ -17,12 +17,13 @@ package com.fernandocejas.android10.sample.domain.interactor;
 
 import com.fernandocejas.android10.sample.domain.executor.PostExecutionThread;
 import com.fernandocejas.android10.sample.domain.executor.ThreadExecutor;
-import com.fernandocejas.arrow.optional.Optional;
 import io.reactivex.Observable;
 import io.reactivex.observers.DisposableObserver;
 import io.reactivex.schedulers.TestScheduler;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
@@ -35,11 +36,13 @@ public class UseCaseTest {
 
   private UseCaseTestClass useCase;
 
-  private TestDisposableObserver testObserver;
+  private TestDisposableObserver<Object> testObserver;
 
   @Mock private ThreadExecutor mockThreadExecutor;
   @Mock private PostExecutionThread mockPostExecutionThread;
 
+  @Rule public ExpectedException expectedException = ExpectedException.none();
+
   @Before
   public void setUp() {
     this.useCase = new UseCaseTestClass(mockThreadExecutor, mockPostExecutionThread);
@@ -48,7 +51,6 @@ public class UseCaseTest {
   }
 
   @Test
-  @SuppressWarnings("unchecked")
   public void testBuildUseCaseObservableReturnCorrectResult() {
     useCase.execute(testObserver, Params.EMPTY);
 
@@ -63,18 +65,25 @@ public class UseCaseTest {
     assertThat(testObserver.isDisposed()).isTrue();
   }
 
-  private static class UseCaseTestClass extends UseCase {
+  @Test
+  public void testShouldFailWhenExecuteWithNullObserver() {
+    expectedException.expect(NullPointerException.class);
+    useCase.execute(null, Params.EMPTY);
+  }
+
+  private static class UseCaseTestClass extends UseCase<Object, Params> {
 
     UseCaseTestClass(ThreadExecutor threadExecutor, PostExecutionThread postExecutionThread) {
       super(threadExecutor, postExecutionThread);
     }
 
-    @Override protected Observable buildUseCaseObservable(Optional<Params> params) {
+    @Override Observable<Object> buildUseCaseObservable(Params params) {
       return Observable.empty();
     }
 
-    @Override public void execute(DisposableObserver observer, Params params) {
-      super.execute(observer, Params.EMPTY);
+    @Override
+    public void execute(DisposableObserver<Object> observer, Params params) {
+      super.execute(observer, params);
     }
   }
 
@@ -93,4 +102,9 @@ public class UseCaseTest {
       // no-op by default.
     }
   }
+
+  private static class Params {
+    private static Params EMPTY = new Params();
+    private Params() {}
+  }
 }

presentation/src/androidTest/java/com/fernandocejas/android10/sample/test/presenter/UserDetailsPresenterTest.java

@@ -17,6 +17,7 @@ package com.fernandocejas.android10.sample.test.presenter;
 
 import android.content.Context;
 import com.fernandocejas.android10.sample.domain.interactor.GetUserDetails;
+import com.fernandocejas.android10.sample.domain.interactor.GetUserDetails.Params;
 import com.fernandocejas.android10.sample.presentation.mapper.UserModelDataMapper;
 import com.fernandocejas.android10.sample.presentation.presenter.UserDetailsPresenter;
 import com.fernandocejas.android10.sample.presentation.view.UserDetailsView;
@@ -27,7 +28,6 @@ import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
 
-import com.fernandocejas.android10.sample.domain.interactor.Params;
 import static org.mockito.BDDMockito.given;
 import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.verify;
@@ -51,6 +51,7 @@ public class UserDetailsPresenterTest {
   }
 
   @Test
+  @SuppressWarnings("unchecked")
   public void testUserDetailsPresenterInitialize() {
     given(mockUserDetailsView.context()).willReturn(mockContext);
 

presentation/src/androidTest/java/com/fernandocejas/android10/sample/test/presenter/UserListPresenterTest.java

@@ -17,7 +17,6 @@ package com.fernandocejas.android10.sample.test.presenter;
 
 import android.content.Context;
 import com.fernandocejas.android10.sample.domain.interactor.GetUserList;
-import com.fernandocejas.android10.sample.domain.interactor.Params;
 import com.fernandocejas.android10.sample.presentation.mapper.UserModelDataMapper;
 import com.fernandocejas.android10.sample.presentation.presenter.UserListPresenter;
 import com.fernandocejas.android10.sample.presentation.view.UserListView;
@@ -49,6 +48,7 @@ public class UserListPresenterTest {
   }
 
   @Test
+  @SuppressWarnings("unchecked")
   public void testUserListPresenterInitialize() {
     given(mockUserListView.context()).willReturn(mockContext);
 
@@ -56,6 +56,6 @@ public class UserListPresenterTest {
 
     verify(mockUserListView).hideRetry();
     verify(mockUserListView).showLoading();
-    verify(mockGetUserList).execute(any(DisposableObserver.class), any(Params.class));
+    verify(mockGetUserList).execute(any(DisposableObserver.class), any(Void.class));
   }
 }

presentation/src/main/java/com/fernandocejas/android10/sample/presentation/internal/di/modules/UserModule.java

@@ -15,16 +15,7 @@
  */
 package com.fernandocejas.android10.sample.presentation.internal.di.modules;
 
-import com.fernandocejas.android10.sample.domain.executor.PostExecutionThread;
-import com.fernandocejas.android10.sample.domain.executor.ThreadExecutor;
-import com.fernandocejas.android10.sample.domain.interactor.GetUserDetails;
-import com.fernandocejas.android10.sample.domain.interactor.GetUserList;
-import com.fernandocejas.android10.sample.domain.interactor.UseCase;
-import com.fernandocejas.android10.sample.domain.repository.UserRepository;
-import com.fernandocejas.android10.sample.presentation.internal.di.PerActivity;
 import dagger.Module;
-import dagger.Provides;
-import javax.inject.Named;
 
 /**
  * Dagger module that provides user related collaborators.
@@ -33,15 +24,4 @@ import javax.inject.Named;
 public class UserModule {
 
   public UserModule() {}
-
-  @Provides @PerActivity @Named(GetUserList.NAME) UseCase provideGetUserListUseCase(
-      GetUserList getUserList) {
-    return getUserList;
-  }
-
-  @Provides @PerActivity @Named(GetUserDetails.NAME) UseCase provideGetUserDetailsUseCase(
-      UserRepository userRepository, ThreadExecutor threadExecutor,
-      PostExecutionThread postExecutionThread) {
-    return new GetUserDetails(userRepository, threadExecutor, postExecutionThread);
-  }
 }

presentation/src/main/java/com/fernandocejas/android10/sample/presentation/presenter/UserDetailsPresenter.java

@@ -21,15 +21,13 @@ import com.fernandocejas.android10.sample.domain.exception.DefaultErrorBundle;
 import com.fernandocejas.android10.sample.domain.exception.ErrorBundle;
 import com.fernandocejas.android10.sample.domain.interactor.DefaultObserver;
 import com.fernandocejas.android10.sample.domain.interactor.GetUserDetails;
-import com.fernandocejas.android10.sample.domain.interactor.UseCase;
-import com.fernandocejas.android10.sample.domain.interactor.Params;
+import com.fernandocejas.android10.sample.domain.interactor.GetUserDetails.Params;
 import com.fernandocejas.android10.sample.presentation.exception.ErrorMessageFactory;
 import com.fernandocejas.android10.sample.presentation.internal.di.PerActivity;
 import com.fernandocejas.android10.sample.presentation.mapper.UserModelDataMapper;
 import com.fernandocejas.android10.sample.presentation.model.UserModel;
 import com.fernandocejas.android10.sample.presentation.view.UserDetailsView;
 import javax.inject.Inject;
-import javax.inject.Named;
 
 /**
  * {@link Presenter} that controls communication between views and models of the presentation
@@ -40,11 +38,11 @@ public class UserDetailsPresenter implements Presenter {
 
   private UserDetailsView viewDetailsView;
 
-  private final UseCase getUserDetailsUseCase;
+  private final GetUserDetails getUserDetailsUseCase;
   private final UserModelDataMapper userModelDataMapper;
 
   @Inject
-  public UserDetailsPresenter(@Named(GetUserDetails.NAME) UseCase getUserDetailsUseCase,
+  public UserDetailsPresenter(GetUserDetails getUserDetailsUseCase,
       UserModelDataMapper userModelDataMapper) {
     this.getUserDetailsUseCase = getUserDetailsUseCase;
     this.userModelDataMapper = userModelDataMapper;
@@ -74,9 +72,7 @@ public class UserDetailsPresenter implements Presenter {
   }
 
   private void getUserDetails(int userId) {
-    final Params params = Params.create();
-    params.putInt(GetUserDetails.PARAM_USER_ID_KEY, userId);
-    this.getUserDetailsUseCase.execute(new UserDetailsObserver(), params);
+    this.getUserDetailsUseCase.execute(new UserDetailsObserver(), Params.forUser(userId));
   }
 
   private void showViewLoading() {

presentation/src/main/java/com/fernandocejas/android10/sample/presentation/presenter/UserListPresenter.java

@@ -21,8 +21,6 @@ import com.fernandocejas.android10.sample.domain.exception.DefaultErrorBundle;
 import com.fernandocejas.android10.sample.domain.exception.ErrorBundle;
 import com.fernandocejas.android10.sample.domain.interactor.DefaultObserver;
 import com.fernandocejas.android10.sample.domain.interactor.GetUserList;
-import com.fernandocejas.android10.sample.domain.interactor.UseCase;
-import com.fernandocejas.android10.sample.domain.interactor.Params;
 import com.fernandocejas.android10.sample.presentation.exception.ErrorMessageFactory;
 import com.fernandocejas.android10.sample.presentation.internal.di.PerActivity;
 import com.fernandocejas.android10.sample.presentation.mapper.UserModelDataMapper;
@@ -31,7 +29,6 @@ import com.fernandocejas.android10.sample.presentation.view.UserListView;
 import java.util.Collection;
 import java.util.List;
 import javax.inject.Inject;
-import javax.inject.Named;
 
 /**
  * {@link Presenter} that controls communication between views and models of the presentation
@@ -42,11 +39,11 @@ public class UserListPresenter implements Presenter {
 
   private UserListView viewListView;
 
-  private final UseCase getUserListUseCase;
+  private final GetUserList getUserListUseCase;
   private final UserModelDataMapper userModelDataMapper;
 
   @Inject
-  public UserListPresenter(@Named(GetUserList.NAME) UseCase getUserListUserCase,
+  public UserListPresenter(GetUserList getUserListUserCase,
       UserModelDataMapper userModelDataMapper) {
     this.getUserListUseCase = getUserListUserCase;
     this.userModelDataMapper = userModelDataMapper;
@@ -114,7 +111,7 @@ public class UserListPresenter implements Presenter {
   }
 
   private void getUserList() {
-    this.getUserListUseCase.execute(new UserListObserver(), Params.EMPTY);
+    this.getUserListUseCase.execute(new UserListObserver(), null);
   }
 
   private final class UserListObserver extends DefaultObserver<List<User>> {