added sample unit test to MeetupViewModel

app/build.gradle.kts

@@ -43,4 +43,4 @@ dependencies {
     androidTestImplementation(TestLibraries.espressoCore)
 }
 
-apply(mapOf("plugin" to "com.google.gms.google-services"))
+//apply(mapOf("plugin" to "com.google.gms.google-services"))

buildSrc/build/kotlin/compileKotlin/caches-jvm/lookups/counters.tab

@@ -1,2 +1,2 @@
-10
-4
+11
+5

buildSrc/src/main/java/Dependencies.kt

@@ -1,12 +1,13 @@
 object CoreLibraries {
     const val kotlin = "org.jetbrains.kotlin:kotlin-stdlib-jdk8:${Versions.kotlinVersion}"
-    const val coroutines = "org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.0-M2"
+
+    const val coroutines =
+        "org.jetbrains.kotlinx:kotlinx-coroutines-core:${Versions.coroutinesVersion}"
     const val koin = "org.koin:koin-android:${Versions.coinVersion}"
     const val koinViewModel = "org.koin:koin-android-viewmodel:${Versions.coinVersion}"
 }
 
 
-
 object ThirdPartyLibraries {
     const val retrofit = "com.squareup.retrofit2:retrofit:2.6.0"
     const val moshi = "com.squareup.moshi:moshi-kotlin:${Versions.moshiVersion}"
@@ -35,4 +36,9 @@ object TestLibraries {
     const val runnner = "com.android.support.test:runner:${Versions.testRunnerVersion}"
     const val espressoCore =
         "com.android.support.test.espresso:espresso-core:${Versions.espressoCoreVersion}"
+    const val mockk = "io.mockk:mockk:${Versions.mockKversion}"
+
+    const val archCoreTesting = "android.arch.core:core-testing:1.0.0"
+    const val coroutinesTesting =
+        "org.jetbrains.kotlinx:kotlinx-coroutines-test:${Versions.coroutinesVersion}"
 }

buildSrc/src/main/java/Versions.kt

@@ -5,6 +5,7 @@ object Release {
 
 object Versions {
 
+    const val mockKversion = "1.9.3"
     /**
      * Sdk Versions
      */
@@ -17,6 +18,7 @@ object Versions {
      */
     const val gradleVersion = "3.5.0-beta05"
     const val kotlinVersion = "1.3.41"
+    const val coroutinesVersion = "1.3.0-M2"
     const val appCompatVersion = "1.0.2"
     const val firebaseVersion = "17.0.0"
     const val constraintLayoutVersion = "1.1.3"

meetupviewmodel/build.gradle.kts

@@ -10,6 +10,10 @@ dependencies {
     implementation(AndroidxLibraries.viewModel)
     implementation(CoreLibraries.koin)
     implementation(CoreLibraries.koinViewModel)
+    testImplementation(TestLibraries.mockk)
+    testImplementation(TestLibraries.jUnit)
+    testImplementation(TestLibraries.archCoreTesting)
+    testImplementation(TestLibraries.coroutinesTesting)
 }
 
 android {
@@ -18,6 +22,9 @@ android {
         minSdkVersion(Versions.minSdkVersion)
         targetSdkVersion(Versions.targetSdkVersion)
     }
+    testOptions {
+        unitTests.isReturnDefaultValues = true
+    }
 }
 buildscript {
 

meetupviewmodel/src/main/java/com/gdgistanbul/viewmodel/MeetupViewModel.kt

@@ -8,10 +8,8 @@ import com.gdgistanbul.model.Event
 import com.gdgistanbul.repo.MeetupRepo
 import kotlinx.coroutines.launch
 
-class MeetupViewModel(val meetupRepo: MeetupRepo) : ViewModel() {
-    init {
-        refreshEvents()
-    }
+class MeetupViewModel(private val meetupRepo: MeetupRepo) : ViewModel() {
+
 
     val eventsLiveData = MutableLiveData<List<Event>>()
     val toastLiveData = MutableLiveData<String>()

meetupviewmodel/src/test/java/com/gdgistanbul/viewmodel/MeetupViewModelTest.kt

@@ -0,0 +1,62 @@
+package com.gdgistanbul.viewmodel
+
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import androidx.lifecycle.Observer
+import com.gdgistanbul.model.Event
+import com.gdgistanbul.repo.MeetupRepo
+import io.mockk.MockKAnnotations
+import io.mockk.coEvery
+import io.mockk.impl.annotations.MockK
+import io.mockk.mockk
+import io.mockk.verify
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.newSingleThreadContext
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.setMain
+import org.junit.After
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.rules.TestRule
+
+class MeetupViewModelTest {
+    @get:Rule
+    var rule: TestRule = InstantTaskExecutorRule()
+
+    private val mainThreadSurrogate = newSingleThreadContext("UI thread")
+
+    @MockK
+    lateinit var meetupRepo: MeetupRepo
+
+    @Before
+    fun initTests() {
+        Dispatchers.setMain(mainThreadSurrogate)
+        MockKAnnotations.init(this)
+    }
+
+    @Test
+    fun `refreshEvents success`() = runBlocking {
+        val eventList: List<Event> = mockk()
+        coEvery { meetupRepo.getEvents() } returns eventList
+        val observer: Observer<List<Event>> = mockk()
+        val viewModel = MeetupViewModel(meetupRepo)
+        viewModel.eventsLiveData.observeForever(observer)
+        viewModel.refreshEvents().join()
+        verify { observer.onChanged(eventList) }
+
+    }
+
+
+    @Test
+    fun `refreshEvents failure`() = runBlocking {
+
+        val viewModel: MeetupViewModel = MeetupViewModel(meetupRepo)
+    }
+
+    @After
+    fun tearDown() {
+        Dispatchers.resetMain() // reset main dispatcher to the original Main dispatcher
+        mainThreadSurrogate.close()
+    }
+}