配置 build.gradle 来用 Spock 对 Andro

在“使用 Android Studio 开发 Web 程序 - 测试”中说明了为什么要选择 Spock Framework 来做为测试时的框架。在操作时，build.gradle 要做一定程度上的配置，才能够使以 Spock 写出来的源代码得以运作，以下将会说明相关配置上的细节。

首先，Spock 的测试源代码需要使用 Groovy 语言来编写，所以 build.gradle 中要先引用 Groovy 的 Gradle Plugin。第一步要在 Root 的 build.gradle 中增加以下内容：

buildscript {
    ...
    dependencies {
        ...
        classpath 'org.codehaus.groovy:groovy-android-gradle-plugin:1.1.0'
    }
}

第二步是在要使用 Groovy 的项目 build.gradle 中增加 apply plugin: 'groovyx.android’ 的内容，让 Gradle 可以正确地识别 Groovy 所写的源代码。

第三步要配置在封装 Apk 的过程中被排除的文件：

packagingOptions {
    exclude 'META-INF/services/org.codehaus.groovy.transform.ASTTransformation'
    exclude 'META-INF/services/org.codehaus.groovy.runtime.ExtensionModule'
}

完成以上的工作就可以配置 Dependencies 以便在撰写程序时可以引用到 Spock Framework 里的 Class。但是光只有 Spock 也只能对一般的 Class 进行测试，如果要测试 Android 控件，牵涉到 Context 的问题，还是要使用官方的 Espresso 或是 Robolectric。

Espresso 的问题不大，只要把 Java 的写法改成 Groovy 套到 Spock 的 Class 结构里就行了。Robolectric 则是要改为引用另一个包：Robospock，依照 Robospock 的官方文件的说明，就可以顺利的使用 Spock 来测试 Android 的控件。RoboSpock 就已经有引用 Robolectric，所以自己的 build.gradle 并不需要再配置一次。只是必须受限于 RoboSpock 生成时所配置的 Robolectric 版本，不一定能使用最新版的 Robolectric。

最后一个要注意的事项是，Espresso 在运行前是要经过实际封装 Apk 的过程，所以 Groovy 在引用时要使用特别为 Android 开发的版本 - org.codehaus.groovy:groovy:2.4.7:grooid，否则很容易会出现超出 64K 的问题。

以下是完整的 build.gradle 的演示内容：

apply plugin: 'com.android.application'
apply plugin: 'groovyx.android'

android {
    compileSdkVersion 24
    buildToolsVersion "25.0.0"

    defaultConfig {
        applicationId "com.example.sampleapp”
        minSdkVersion 9
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

    }
    testOptions {
        unitTests.returnDefaultValues = true
    }
    packagingOptions {
        exclude 'META-INF/services/org.codehaus.groovy.transform.ASTTransformation'
        exclude 'META-INF/services/org.codehaus.groovy.runtime.ExtensionModule'
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    testCompile 'org.codehaus.groovy:groovy-all:2.4.7'
    testCompile 'org.spockframework:spock-core:1.0-groovy-2.4'
    testCompile 'org.robospock:robospock:1.0.1'
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    androidTestCompile('com.android.support.test.espresso:espresso-contrib:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    androidTestCompile 'org.codehaus.groovy:groovy:2.4.7:grooid'
    androidTestCompile('org.spockframework:spock-core:1.0-groovy-2.4') {
        exclude group: 'org.codehaus.groovy'
        exclude group: 'junit'
    }
}

撰写 Spock 测试前要先手动在 androidTest 或是 test 路径下增加 groovy 的文件夹，其下再依据所属的 Package 产生路径结构。

最后，由于相容性的关系，在编译的过程中会持续出现以下的讯息，但实际操作时并没有阻挡或影响到测试程序的运行，所以可以忽略、不用理会。

:module:transformClassesWithDexForDebugAndroidTest
AGPBI: {"kind":"error","text":"warning: Ignoring InnerClasses attribute for an anonymous inner class","sources":[{}]}
AGPBI: {"kind":"error","text":"(groovyjarjarantlr.TokenStreamRewriteEngine$1) that doesn\u0027t come with an","sources":[{}]}
AGPBI: {"kind":"error","text":"associated EnclosingMethod attribute. This class was probably produced by a","sources":[{}]}
AGPBI: {"kind":"error","text":"compiler that did not target the modern .class file format. The recommended","sources":[{}]}
AGPBI: {"kind":"error","text":"solution is to recompile the class from source, using an up-to-date compiler","sources":[{}]}
AGPBI: {"kind":"error","text":"and without specifying any \"-target\" type options. The consequence of ignoring","sources":[{}]}
AGPBI: {"kind":"error","text":"this warning is that reflective operations on this class will incorrectly","sources":[{}]}
AGPBI: {"kind":"error","text":"indicate that it is *not* an inner class.","sources":[{}]}
AGPBI: {"kind":"error","text":"warning: Ignoring InnerClasses attribute for an anonymous inner class","sources":[{}]}
AGPBI: {"kind":"error","text":"(groovyjarjarantlr.build.ANTLR$1) that doesn\u0027t come with an","sources":[{}]}
AGPBI: {"kind":"error","text":"associated EnclosingMethod attribute. This class was probably produced by a","sources":[{}]}
AGPBI: {"kind":"error","text":"compiler that did not target the modern .class file format. The recommended","sources":[{}]}
AGPBI: {"kind":"error","text":"solution is to recompile the class from source, using an up-to-date compiler","sources":[{}]}
AGPBI: {"kind":"error","text":"and without specifying any \"-target\" type options. The consequence of ignoring","sources":[{}]}
AGPBI: {"kind":"error","text":"this warning is that reflective operations on this class will incorrectly","sources":[{}]}
AGPBI: {"kind":"error","text":"indicate that it is *not* an inner class.","sources":[{}]}
AGPBI: {"kind":"error","text":"warning: Ignoring InnerClasses attribute for an anonymous inner class","sources":[{}]}
AGPBI: {"kind":"error","text":"(groovyjarjarantlr.debug.misc.ASTFrame$1) that doesn\u0027t come with an","sources":[{}]}
AGPBI: {"kind":"error","text":"associated EnclosingMethod attribute. This class was probably produced by a","sources":[{}]}
AGPBI: {"kind":"error","text":"compiler that did not target the modern .class file format. The recommended","sources":[{}]}
AGPBI: {"kind":"error","text":"solution is to recompile the class from source, using an up-to-date compiler","sources":[{}]}
AGPBI: {"kind":"error","text":"and without specifying any \"-target\" type options. The consequence of ignoring","sources":[{}]}
AGPBI: {"kind":"error","text":"this warning is that reflective operations on this class will incorrectly","sources":[{}]}
AGPBI: {"kind":"error","text":"indicate that it is *not* an inner class.","sources":[{}]}