[BAEL-2653] Added kotlin immutable collections code (#6563)

* Added kotlin immutable collections code

* corrected wrong junit version

kotlin-libraries/pom.xml

@@ -19,6 +19,14 @@
             <name>exposed</name>
             <url>https://dl.bintray.com/kotlin/exposed</url>
         </repository>
+        <repository>
+            <snapshots>
+                <enabled>false</enabled>
+            </snapshots>
+            <id>kotlinx</id>
+            <name>bintray</name>
+            <url>https://dl.bintray.com/kotlin/kotlinx</url>
+        </repository>
     </repositories>
 
     <dependencies>
@@ -112,9 +120,30 @@
             <version>3.3.0</version>
             <type>pom</type>
         </dependency>
+
+        <!-- https://mvnrepository.com/artifact/junit/junit -->
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>27.1-jre</version>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/org.jetbrains.kotlinx/kotlinx-collections-immutable -->
+        <dependency>
+            <groupId>org.jetbrains.kotlinx</groupId>
+            <artifactId>kotlinx-collections-immutable</artifactId>
+            <version>0.1</version>
+        </dependency>
     </dependencies>
 
     <properties>
+        <junit.version>4.12</junit.version>
         <mockito-kotlin.version>1.5.0</mockito-kotlin.version>
         <kodein.version>4.1.0</kodein.version>
         <klaxon.version>3.0.4</klaxon.version>

kotlin-libraries/src/test/kotlin/com/baeldung/kotlin/immutable/KotlinxImmutablesUnitTest.kt

@@ -0,0 +1,27 @@
+package com.baeldung.kotlin.immutable
+
+import junit.framework.Assert.assertEquals
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.immutableListOf
+import org.junit.Rule
+import org.junit.Test
+import org.junit.rules.ExpectedException
+
+class KotlinxImmutablesUnitTest{
+
+
+  @Rule
+  @JvmField
+  var ee : ExpectedException = ExpectedException.none()
+
+  @Test
+  fun givenKICLList_whenAddTried_checkExceptionThrown(){
+
+      val list: ImmutableList<String> = immutableListOf("I", "am", "immutable")
+
+      list.add("My new item")
+
+      assertEquals(listOf("I", "am", "immutable"), list)
+
+  }
+}

kotlin-libraries/src/test/kotlin/com/baeldung/kotlin/immutable/ReadOnlyUnitTest.kt

@@ -0,0 +1,73 @@
+package com.baeldung.kotlin.immutable
+
+import com.google.common.collect.ImmutableList
+import com.google.common.collect.ImmutableSet
+import junit.framework.Assert.assertEquals
+import org.junit.Rule
+import org.junit.Test
+import org.junit.rules.ExpectedException
+
+class ReadOnlyUnitTest{
+
+    @Test
+    fun givenReadOnlyList_whenCastToMutableList_checkNewElementsAdded(){
+
+        val list: List<String> = listOf("This", "Is", "Totally", "Immutable")
+
+        (list as MutableList<String>)[2] = "Not"
+
+        assertEquals(listOf("This", "Is", "Not", "Immutable"), list)
+
+    }
+
+    @Rule
+    @JvmField
+    var ee : ExpectedException = ExpectedException.none()
+
+    @Test
+    fun givenImmutableList_whenAddTried_checkExceptionThrown(){
+
+        val list: List<String> = ImmutableList.of("I", "am", "actually", "immutable")
+
+        ee.expect(UnsupportedOperationException::class.java)
+
+        (list as MutableList<String>).add("Oops")
+
+    }
+
+    @Test
+    fun givenMutableList_whenCopiedAndAddTried_checkExceptionThrown(){
+
+        val mutableList : List<String> = listOf("I", "Am", "Definitely", "Immutable")
+
+        (mutableList as MutableList<String>)[2] = "100% Not"
+
+        assertEquals(listOf("I", "Am", "100% Not", "Immutable"), mutableList)
+
+        val list: List<String> = ImmutableList.copyOf(mutableList)
+
+        ee.expect(UnsupportedOperationException::class.java)
+
+        (list as MutableList<String>)[2] = "Really?"
+
+    }
+
+    @Test
+    fun givenImmutableSetBuilder_whenAddTried_checkExceptionThrown(){
+
+        val mutableList : List<String> = listOf("Hello", "Baeldung")
+        val set: ImmutableSet<String> = ImmutableSet.builder<String>()
+                .add("I","am","immutable")
+                .addAll(mutableList)
+                .build()
+
+        assertEquals(setOf("Hello", "Baeldung", "I", "am", "immutable"), set)
+
+        ee.expect(UnsupportedOperationException::class.java)
+
+        (set as MutableSet<String>).add("Oops")
+
+    }
+
+
+}