Social App (koin)

snippet01.groovy

// build.gradle
buildscript {
  ext.versions = [
    'kotlin': '1.2.41',
    'supportLibrary': '27.1.1',
    'jacoco': '0.8.1',
    'archComponents': '1.1.1',
    'koin': '0.9.3',
  ]
...
}

snippet02.groovy

// app/build.gradle
apply plugin: 'com.android.application'
apply plugin: 'org.jetbrains.kotlin.android'
apply plugin: 'org.jetbrains.kotlin.kapt'

...

dependencies {
  ...

  implementation "android.arch.lifecycle:extensions:$versions.archComponents"
  kapt "android.arch.lifecycle:compiler:$versions.archComponents"

  implementation "org.koin:koin-android:$versions.koin"
  implementation "org.koin:koin-android-architecture:$versions.koin"
}

snippet03.kt

package net.rafaeltoledo.social

import android.arch.lifecycle.ViewModel

class MainViewModel(private val string: String) : ViewModel() {

  fun getString() = string
}

snippet04.kt

package net.rafaeltoledo.social 

import android.os.Bundle 
import android.support.v7.app.AppCompatActivity 
import android.widget.TextView 

import org.koin.android.architecture.ext.viewModel 

class MainActivity : AppCompatActivity() { 
  private val mainViewModel: MainViewModel by viewModel() 
  
  override fun onCreate(savedInstanceState: Bundle?) { 
    super.onCreate(savedInstanceState) 
    setContentView(TextView(this).apply { 
      id = R.id.content 
      text = mainViewModel.getString() 
    }) 
  } 
}

snippet05.kt

// FirstModule.kt 
package net.rafaeltoledo.social.di 

import org.koin.dsl.module.applicationContext 

val firstModule = applicationContext { 
  bean { "Social App" } 
}

snippet06.kt

// ViewModelModule.kt 
package net.rafaeltoledo.social.di 

import net.rafaeltoledo.social.MainViewModel 

import org.koin.android.architecture.ext.viewModel 
import org.koin.dsl.module.applicationContext 

val viewModelModule = applicationContext { 
  viewModel { MainViewModel(get()) } 
} 

snippet07.kt

package net.rafaeltoledo.social 

import android.app.Application 

import net.rafaeltoledo.social.di.firstModule 
import net.rafaeltoledo.social.di.viewModelModule 

import org.koin.android.ext.android.startKoin 

class SocialApp : Application() { 
  
  override fun onCreate() { 
    super.onCreate() 
    startKoin(listOf( 
      viewModelModule, 
      firstModule 
    )) 
  } 
}

snippet08.kt

// TestSetup.kt 
package net.rafaeltoledo.social 

import android.app.Application 
import net.rafaeltoledo.social.di.viewModelModule 
import org.koin.android.ext.android.startKoin 
import org.koin.dsl.module.applicationContext 

class TestSocialApp : SocialApp() { 
  
  fun overrideStringValue(newValue: String) { 
    // Override value 
    // This behavior should be explicit in a future version of Koin 
    // See: https://github.com/Ekito/koin/pull/123 
    loadKoinModules(listOf( 
      applicationContext { bean { newValue } } 
    )) 
  } 
} 

snippet09.kt

package net.rafaeltoledo.social 

import android.widget.TextView 
import com.google.common.truth.Truth.assertThat 
import org.junit.Test 
import org.junit.runner.RunWith 
import org.robolectric.Robolectric 
import org.robolectric.RobolectricTestRunner 
import org.robolectric.RuntimeEnvironment 

@RunWith(RobolectricTestRunner::class) 
class MainActivityTest { 
  
  @Test 
  fun checkIfActivityIsSuccessfullyCreated() { 
    // Arrange 
    val newValue = "Test Social App" 
    val app = RuntimeEnvironment.application as TestSocialApp 
    app.overrideStringValue(newValue) 
    val activity = Robolectric.setupActivity(MainActivity::class.java) 
    
    // Act - nothing to do 
    
    // Assert 
    val text = activity.findViewById(R.id.content) 
    assertThat(text.text).isEqualTo(newValue) 
  } 
}