Dagger 2 generated test component not recognized

Question

I\'m hoping that this is just something I\'m doing wrong here. I\'m trying to use Dagger 2.0 to inject dependencies for my JUnit tests (not Espresso tests, just pu

Answer 1

I found a workaround, just in case anybody gets stuck with this issue in the future. It appears the testAnnotationProcessor command in the android gradle plugin does not work for test modules (possibly a bug in their implementation?). So you can write testAnnotationProcessor and your build.gradle will compile but it seems to not work properly.

The workaround is to fall back to the older third-party annotation processing plugin by Hugo Visser (android-apt).

To do that, add the following to your buildscript dependencies in your main build.gradle:

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.0-rc1'

        // ADD THIS LINE HERE vvv
        classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
    }
}

Then, in your individual module's build.gradle, add the following line at the top:

apply plugin: 'com.android.library'

// ADD THIS LINE HERE vvv
apply plugin: 'com.neenbedankt.android-apt'

Finally, instead of using testAnnotationProcessor and annotationProcessor, just use apt and testApt:

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.2.0'

    compile 'com.google.dagger:dagger:2.9'
    // USE apt INSTEAD OF annotationProcessor HERE vvv
    apt 'com.google.dagger:dagger-compiler:2.9'

    testCompile 'com.google.dagger:dagger:2.9'
    // USE testApt INSTEAD OF testAnnotationProcessor HERE vvv
    testApt 'com.google.dagger:dagger-compiler:2.9'

    testCompile 'junit:junit:4.12'
}

Note that you must use the 1.8 version of android-apt, as the 1.4 version does not ship with the testApt command/function/whatever.