Add base dao test for reduce boilerplate for testing DAOs

app/src/androidTest/java/com/akshay/newsapp/core/utils/DaoTest.kt

@@ -0,0 +1,27 @@
+package com.akshay.newsapp.core.utils
+
+import android.content.Context
+import androidx.room.Room
+import androidx.room.RoomDatabase
+import androidx.test.core.app.ApplicationProvider
+import org.junit.After
+import org.junit.Before
+
+/**
+ * Base class to reduce boilerplate code for testing DAO(s) of [RoomDatabase].
+ */
+abstract class DaoTest<Database: RoomDatabase>(
+        private val database: Class<Database>
+): MockitoTest() {
+
+    protected lateinit var db: Database
+
+    @Before
+    override fun setup() {
+        super.setup()
+        db = Room.inMemoryDatabaseBuilder(ApplicationProvider.getApplicationContext<Context>(), database).build()
+    }
+
+    @After
+    fun teardown() = db.close()
+}

app/src/androidTest/java/com/akshay/newsapp/news/storage/NewsArticlesDaoTest.kt

@@ -1,31 +1,17 @@
 package com.akshay.newsapp.news.storage
 
-import android.content.Context
-import androidx.room.Room
-import androidx.test.core.app.ApplicationProvider
 import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.akshay.newsapp.core.utils.DaoTest
 import com.akshay.newsapp.core.utils.assertItems
 import com.akshay.newsapp.news.model.NewsArticles
 import kotlinx.coroutines.runBlocking
 import org.hamcrest.CoreMatchers.equalTo
 import org.hamcrest.MatcherAssert.assertThat
-import org.junit.After
-import org.junit.Before
 import org.junit.Test
 import org.junit.runner.RunWith
 
 @RunWith(AndroidJUnit4::class)
-class NewsArticlesDaoTest {
-
-    private lateinit var db: NewsDatabase
-
-    @Before
-    fun initDb() {
-        db = Room.inMemoryDatabaseBuilder(ApplicationProvider.getApplicationContext<Context>(), NewsDatabase::class.java).build()
-    }
-
-    @After
-    fun closeDb() = db.close()
+class NewsArticlesDaoTest : DaoTest<NewsDatabase>(NewsDatabase::class.java) {
 
     @Test
     @Throws(InterruptedException::class)
@@ -50,5 +36,4 @@ class NewsArticlesDaoTest {
         // THEN
         db.newsArticlesDao().getNewsArticles().assertItems(input)
     }
-
 }

app/src/sharedTest/kotlin/com/akshay/newsapp/core/utils/MockitoTest.kt

@@ -19,7 +19,7 @@ import org.mockito.MockitoAnnotations
 abstract class MockitoTest {
 
     @Before
-    fun setup() {
+    open fun setup() {
         MockitoAnnotations.initMocks(this)
     }
 }