Presenter层测试（cover RxJava,Mockit

• Presenter层未使用Android相关API，无需引入Robolectric
• 引入PowerMock，介入私有方法mock
• AndroidSchedulers.mainThread需要通过Rule规则挂钩子Hook住相关API
• View层为接口持有，通过普通Mockito验证
• 需将一个方法的多个分支拆分成多个Test方法，保证每个Test的使用新的Mock实例防止结果互相干扰

AndroidSchedulers.mainThread Hook相关Rule规则

RxSchedulersOverrideRule.java

import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;

import rx.Scheduler;
import rx.android.plugins.RxAndroidPlugins;
import rx.android.plugins.RxAndroidSchedulersHook;
import rx.functions.Func1;
import rx.plugins.RxJavaHooks;
import rx.schedulers.Schedulers;

public class RxSchedulersOverrideRule implements TestRule {

    private final RxAndroidSchedulersHook mRxAndroidSchedulersHook = new RxAndroidSchedulersHook() {
        @Override
        public Scheduler getMainThreadScheduler() {
            return Schedulers.immediate();
        }
    };

    private final Func1<Scheduler, Scheduler> mRxJavaImmediateScheduler =
            new Func1<Scheduler, Scheduler>() {
                @Override
                public Scheduler call(Scheduler scheduler) {
                    return Schedulers.immediate();
                }
            };

    @Override
    public Statement apply(final Statement base, Description description) {
        return new Statement() {
            @Override
            public void evaluate() throws Throwable {
                RxAndroidPlugins.getInstance().reset();
                RxAndroidPlugins.getInstance().registerSchedulersHook(mRxAndroidSchedulersHook);

                RxJavaHooks.reset();
                RxJavaHooks.setOnIOScheduler(mRxJavaImmediateScheduler);
                RxJavaHooks.setOnNewThreadScheduler(mRxJavaImmediateScheduler);

                base.evaluate();

                RxAndroidPlugins.getInstance().reset();
                RxJavaHooks.reset();
            }
        };
    }
}

测试类引入Rule规则

    @Rule
    public final RxSchedulersOverrideRule mOverrideSchedulersRule = new RxSchedulersOverrideRule();

代码Sample

package com.nd.sdp.live.core.list.presenter;

import com.nd.sdp.live.RxSchedulersOverrideRule;
import com.nd.sdp.live.core.TestException;
import com.nd.sdp.live.core.list.model.VideoBroadcastList;
import com.nd.sdp.live.core.play.entity.VideoLiveBroadcast;

import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Matchers;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.api.support.membermodification.MemberMatcher;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

import java.util.ArrayList;

import rx.Observable;
import rx.android.plugins.RxAndroidPlugins;

import static org.mockito.Matchers.anyInt;
import static org.mockito.Matchers.anyListOf;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.verify;

/**
 * 实现层测试
 * Created by Young on 2017/4/19.
 */
@PrepareForTest({LiveListPresenterImpl.class})
@RunWith(PowerMockRunner.class)
public class LiveListPresenterImplTest {

    private ILiveListPresenter mLiveListPresenter;
    private ILiveListPresenter.View mView;

    @Rule
    public final RxSchedulersOverrideRule mOverrideSchedulersRule = new RxSchedulersOverrideRule();

    @Before
    public void setUp() throws Exception {
        mView = mock(ILiveListPresenter.View.class);
        LiveListPresenterImpl liveListPresenter = new LiveListPresenterImpl(mView);
        mLiveListPresenter = PowerMockito.spy(liveListPresenter);
    }

    @Test
    public void getBroadcastList() throws Exception {
        // With full Data
        VideoBroadcastList result = new VideoBroadcastList();
        result.items = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            result.items.add(new VideoLiveBroadcast());
        }
        PowerMockito.when(mLiveListPresenter, MemberMatcher.method(LiveListPresenterImpl.class, "getListData", int.class))
                .withArguments(0)
                .thenReturn(Observable.just(result));
        mLiveListPresenter.getBroadcastList();
        verify(mView, never()).setNoMoreData();
        verify(mView).setRefreshing();
        verify(mView).refreshComplete();
    }

    @Test
    public void testGetBroadCastWithNoMoreData() throws Exception {
        VideoBroadcastList result = new VideoBroadcastList();
        result.items = new ArrayList<>();
        PowerMockito.when(mLiveListPresenter, MemberMatcher.method(LiveListPresenterImpl.class, "getListData", int.class))
                .withArguments(0)
                .thenReturn(Observable.just(result));
        mLiveListPresenter.getBroadcastList();
        verify(mView).setRefreshing();
        verify(mView).setNoMoreData();
        verify(mView).refreshComplete();
    }

    @Test
    public void testGetBroadCastWithException() throws Exception {
        // Exception
        Throwable throwable = new TestException();
        PowerMockito.when(mLiveListPresenter, MemberMatcher.method(LiveListPresenterImpl.class, "getListData", int.class))
                .withArguments(0)
                .thenReturn(Observable.error(throwable));
        mLiveListPresenter.getBroadcastList();
        verify(mView).error(throwable);
        verify(mView).setNoMoreData();
        verify(mView).refreshComplete();
    }

    @Test
    public void getMoreBroadcast() throws Exception {
        // With full Data
        VideoBroadcastList result = new VideoBroadcastList();
        result.items = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            result.items.add(new VideoLiveBroadcast());
        }
        PowerMockito.when(mLiveListPresenter, MemberMatcher.method(LiveListPresenterImpl.class, "getListData", int.class))
                .withArguments(anyInt())
                .thenReturn(Observable.just(result));
        mLiveListPresenter.getMoreBroadcast(1);
        verify(mView, never()).setNoMoreData();
        verify(mView).addListData(anyListOf(VideoLiveBroadcast.class));
    }

    @Test
    public void getMoreBraodCastWithNoMoreData() throws Exception {
        VideoBroadcastList result = new VideoBroadcastList();
        result.items = new ArrayList<>();
        PowerMockito.when(mLiveListPresenter, MemberMatcher.method(LiveListPresenterImpl.class, "getListData", int.class))
                .withArguments(anyInt())
                .thenReturn(Observable.just(result));
        mLiveListPresenter.getMoreBroadcast(1);
        verify(mView).setNoMoreData();
    }

    @Test
    public void getMoreBroadCastWithException() throws Exception {
        Throwable throwable = new TestException();
        PowerMockito.when(mLiveListPresenter, MemberMatcher.method(LiveListPresenterImpl.class, "getListData", int.class))
                .withArguments(Matchers.anyInt())
                .thenReturn(Observable.error(throwable));
        mLiveListPresenter.getMoreBroadcast(1);
        verify(mView).error(throwable);
        verify(mView).setNoMoreData();
    }

    @Test
    public void onDestroy() throws Exception {
        VideoBroadcastList result = new VideoBroadcastList();
        result.items = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            result.items.add(new VideoLiveBroadcast());
        }
        PowerMockito.when(mLiveListPresenter, MemberMatcher.method(LiveListPresenterImpl.class, "getListData", int.class))
                .withArguments(anyInt())
                .thenReturn(Observable.just(result));
        mLiveListPresenter.getBroadcastList();
        mLiveListPresenter.getMoreBroadcast(1);
        mLiveListPresenter.getBroadcastList();
        mLiveListPresenter.onDestroy();
    }

    @After
    public void tearDown() throws Exception {
        RxAndroidPlugins.getInstance().reset();
    }
}