ProArun · August 19, 2023 16:32 · Aug 19, 2023
diff --git a/LiveDataUtils.kt b/LiveDataUtils.kt
@@ -0,0 +1,33 @@
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.Observer
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.TimeUnit
+import java.util.concurrent.TimeoutException
+
+fun <T> LiveData<T>.getOrAwaitValue(
+    time: Long = 2,
+    timeUnit: TimeUnit = TimeUnit.SECONDS,
+    afterObserve: () -> Unit = {}
+): T {
+    var data: T? = null
+    val latch = CountDownLatch(1)
+    val observer = object : Observer<T> {
+        override fun onChanged(value: T) {
+            data = value
+            latch.countDown()
+            this@getOrAwaitValue.removeObserver(this)
+        }
+    }
+    this.observeForever(observer)
+
+    afterObserve.invoke()
+
+    // Don't wait indefinitely if the LiveData is not set.
+    if (!latch.await(time, timeUnit)) {
+        this.removeObserver(observer)
+        throw TimeoutException("LiveData value was never set.")
+    }
+
+    @Suppress("UNCHECKED_CAST")
+    return data as T
+}
diff --git a/Quote.kt b/Quote.kt
@@ -0,0 +1,7 @@
+@Entity
+data class Quote(
+  @PrimaryKey(autoGenerate = true)
+  val id: Int,
+  val text: String,
+  val author: String
+)
diff --git a/QuoteDatabase.kt b/QuoteDatabase.kt
@@ -0,0 +1,4 @@
+@Database(entities = [Quote::class],version = 1)
+abstract class QuoteDatabase : RoomDatabase(){
+  abstract fun quoteDao(): QuotesDao
+}
diff --git a/QuotesDao.kt b/QuotesDao.kt
@@ -0,0 +1,16 @@
+interface QuotesDao {
+  @Insert
+  suspend fun insertQuote(quote: Quote)
+
+  @Update
+  suspend fun updateQuote(quote: Quote)
+
+  @Query("DELETE FROM quote")
+  suspend fun delete()
+
+  @Query("SELECT * FROM quote")
+  fun getQuotes():LiveData<List<Quote>>
+
+  @Query("SELECT * FROM quote where id = :quoteId")
+  suspend fun gerQuoteById()
+}
diff --git a/QuotesDaoTest.kt b/QuotesDaoTest.kt
@@ -0,0 +1,47 @@
+class QuotesDaoTest{
+
+  @get:Rule
+  val instantExecutorRule = InstantTaskExecutorRule()//this will execute architecture component code syncronasly
+
+  lateinit var quoteDatabase: QuoteDatabase
+  lateinit var quotesDao: QuotesDao
+
+  @Before
+  fun setUp(){
+
+    quoteDatabse = Room.inMemoryDatabseBuilder(
+      ApplicationProvider.getApplicationContext(),
+      QuoteDatabase::Class.java
+    ).allowMainThreadQueries().build()//allowMainThreadQueries():- This method will makesure all query will run on main thread.
+
+    quotesDao = quoteDatabase.quoteDao()
+  }
+
+  @After
+  fun tearDown(){
+      quoteDatabase.close()
+  }
+
+  @Test
+  fun `insertQuote expected single quote`() = runBlocking{//this runBlocking will block the thread until all the code of this methord is not executed
+    val quote = Quote(id:0,text:"This is a test quote",author:"CheezyCode")
+    quotesDao.insertQuote(quote)
+
+    val result = quotesDao.getQuotes().getOrAwaitValue()
+
+    Assert.assertEquals(1,result.size)
+    Assert.assertEquals("This is a test quote",reqult[0].text)
+  }
+
+  @Test
+  fun `deleteQuote expected no quote`() = runBlocking{//this runBlocking will block the thread until all the code of this methord is not executed
+    val quote = Quote(id:0,text:"This is a test quote",author:"CheezyCode")
+    quotesDao.insertQuote(quote)
+
+    quotesDao.delete()
+
+    val result = quotesDao.getQuotes().getOrAwaitValue()
+
+    Assert.assertEquals(0,result.size)
+  }
+}
diff --git a/build.gradle b/build.gradle
@@ -0,0 +1,15 @@
+plugins{
+  id 'kotlin-kapt'
+}
+
+dependencies {
+  def room_version = "2.4.3"
+  implementation "androidx.room:room-runtime: $room_version"
+  implementation "androidx.room:room-ktx: $room_version"
+  kapt "androidx.room:room-compiler: $room_version"
+
+  testImplementation "androidx.room:room-testing: $room_version"
+  androidTestImplementation "androidx.room:room-testing: $room_version"
+  testImplementation "androidx.arch.core:core-testing:2.1.0"
+  androidTestImplementation "androidx.arch.core:core-testing:2.1.0"
+}