Android Instrumentation+esspresso客户端单元测试

代码参考：https://github.com/googlesamples/android-testing

解释参考：

https://www.jianshu.com/p/5732b4afd12f

官网教程:

https://developer.android.google.cn/training/testing/unit-testing/local-unit-tests#setup

看了很多单元测试，做起来都异常复杂。Instrumentation的一直没有做成功，放弃了。

2018年以后，testCompile这个配置改成了testImplementation,这里用的是最新版的，采用新版的配置。

一、junit

gradle添加依赖包：

testImplementation 'junit:junit:4.12'

　　

在项目src/com...../test 目录下新建junit的用例：

public class EmailValidatorTest {
    @Test
    public void booleanTest() {
        boolean a = true;
        Assert.assertEquals(a,true);
    }
}

　　

二、Instrumentation 不会搞，网上的教程基本都是eclipse的，实在不知道是哪些依赖包，好像已经都失效了？

三、Robolectric的单元测试

添加gradle依赖：

testImplementation "org.robolectric:robolectric:3.6.1"

　　

添加其他配置

android {
//    Robolectric
    testOptions {
        unitTests.includeAndroidResources = true
    }
}    

　　

编写测试用例：

import android.content.Context;
import androidx.test.core.app.ApplicationProvider;
import org.junit.Test;

import static com.google.common.truth.Truth.assertThat;

public class UnitTestSampleJava {
    private static final String FAKE_STRING = "HELLO_WORLD";
    private Context context = ApplicationProvider.getApplicationContext();

    @Test
    public void readStringFromContext_LocalizedString() {
        // Given a Context object retrieved from Robolectric...
        ClassUnderTest myObjectUnderTest = new ClassUnderTest(context);

        // ...when the string is returned from the object under test...
        String result = myObjectUnderTest.getHelloWorldString();

        // ...then the result should be the expected one.
        assertThat(result).isEqualTo(FAKE_STRING);
    }
}

　　

四、Mockito

添加gradle依赖：

// Optional -- Mockito framework
    testImplementation 'org.mockito:mockito-core:1.10.19'
//mockito
    androidTestImplementation 'org.mockito:mockito-core:1.10.19'

　　

编写用例

import android.content.Context;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.mockito.junit.MockitoJUnitRunner;

import static com.google.common.truth.Truth.assertThat;
import static org.mockito.Mockito.when;

@RunWith(MockitoJUnitRunner.class)
public class UnitTestSample {

    private static final String FAKE_STRING = "HELLO WORLD";

    @Mock
    Context mockContext;

    @Test
    public void readStringFromContext_LocalizedString() {
        // Given a mocked Context injected into the object under test...
        when(mockContext.getString(R.string.hello_world))
                .thenReturn(FAKE_STRING);
        ClassUnderTest myObjectUnderTest = new ClassUnderTest(mockContext);

        // ...when the string is returned from the object under test...
        String result = myObjectUnderTest.getHelloWorldString();

        // ...then the result should be the expected one.
        assertThat(result, is(FAKE_STRING));
    }
}