Android Build System

source: https://ejf.io/android/build_system/

Tips

• Use the daemon
  • --daemon or org.gradle.debug = true
• Give it enough memeory
• Control the number of threads
• Use the latest build tools
• Get an SSD
• Don’t use timestamps or commit numbers in debug build files

Try:

android {
    dexOptions {
        dexInProcess = true
    }
}

Consider having a development flavor using min SDK 21, as it’s going to be faster.

android.productFlavors {
    normal
    dev {
        minSdkVersion 21
    }
}

Testing

Test dependencies

dependencies {
    compile ".."
    testCompile "junit:junit:4.12"
    testCompile "org.mockito:mockito-core:1.9.5"
}

Unit testing

config:

unitTests.all {
    jvmArgs "-XX:MaxPermSize=256m"

    beforeTest { descriptor ->
        logger.lifecycle("Running test: " + descriptor)
    }
}

Using a test project

Use a separate project just for the test APK.

In main project:

apply plugin: 'com.android.application'
android {
    ...
    publishNonDefault true
}

In test project:

apply plugin: 'com.android.test'
android {
    targetProjectPath ':app'
    targetVariant 'debug'

    defaultConfig {
        minSdkVersion 8
        testInstrumentationRunner 'android.support.test.runner.AndroidJUnitRunner'
    }
}

Test code then lives in the main source set of your test project.

Instrumentation tag still needs to be added to the test project manifest, however they’re hoping to be able to remove this step soon:

<manifest ...>
    <instrumentation
        android:name="android.support.test.runner.AndroidJUnitRunner"
        android:targetPackage="com.example.app" />
</manifest>

Running task on test project:

./gradlew :testProject:connectedAndroidTest

One note on all of this is to make sure that you avoid build tools and dependency version conflicts! Main APK and Test APK need to have the same Build Tools version, and same versions for dependencies. This should be common sense (since you want to test the same versions of everything).

Native Support

New plugins

New plugins for native (content at link may change):

• com.android.model.application - *.apk
• com.android.model.library - *.aar
• com.android.model.native - *.so

In build.gradle:

apply plugin: 'com.android.model.application'
model {
    android {
        compileSdkVersion = 22
        buildToolsVersion = "22.0.1"

        ndk.with {
            moduleName = "native"
            // and other configurations like the following
            CFlags.add("-DCUSTOM_DEFINE")
            cppFlags.add("-DCUSTOM_DEFINE")
            ldFlags.add("-L/custom/lib/path")
            ldLibs.add("log")
            stl = "stlport_static"
        }
    }
}

Inter-module dependencies

Inter-module dependencies for native code, using a library project for the native code:

apply plugin: 'com.android.model.application'
model {
    android.sources {
        main {
            jni {
                dependencies {
                    project ":lib"
                }
            }
        }
    }
}

Perhaps the lib project with native code is set up like this:

apply plugin: "com.android.model.native"
model {
    android {
        compileSdkVersion = 21
    }
    android.ndk {
        moduleName = "hello"
    }
}

Extending the Android plugin

afterEvaluate

Old way:

project.afterEvaluate {
    def task = project.tasks.getByName('transformClassesWithInstantRunForDebug')
    // ...
}

• not part of the official API
• no guarantee that task names will be stable
• no guarantee that things won’t be merged or split