From 1b454b7267f3d6c246e007cb39442e444f470aff Mon Sep 17 00:00:00 2001
From: Graham Cox <graham@grahamcox.co.uk>
Date: Fri, 6 Apr 2018 12:08:33 +0100
Subject: [PATCH] Examples for BAEL-1169 (#3934)

---
 .../com/baeldung/kotlin/objects/Counter.kt    | 15 ++++++++
 .../baeldung/kotlin/objects/ObjectsTest.kt    | 36 +++++++++++++++++++
 .../com/baeldung/kotlin/objects/OuterClass.kt | 10 ++++++
 .../kotlin/objects/ReverseStringComparator.kt |  5 +++
 .../kotlin/objects/SimpleSingleton.kt         |  7 ++++
 .../baeldung/kotlin/objects/StaticClass.kt    |  8 +++++
 6 files changed, 81 insertions(+)
 create mode 100644 core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/Counter.kt
 create mode 100644 core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/ObjectsTest.kt
 create mode 100644 core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/OuterClass.kt
 create mode 100644 core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/ReverseStringComparator.kt
 create mode 100644 core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/SimpleSingleton.kt
 create mode 100644 core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/StaticClass.kt

diff --git a/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/Counter.kt b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/Counter.kt
new file mode 100644
index 0000000000..46ba42e1e5
--- /dev/null
+++ b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/Counter.kt
@@ -0,0 +1,15 @@
+package com.baeldung.kotlin.objects
+
+object Counter {
+    private var count: Int = 0
+
+    fun currentCount() = count
+
+    fun increment() {
+        ++count
+    }
+
+    fun decrement() {
+        --count
+    }
+}
diff --git a/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/ObjectsTest.kt b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/ObjectsTest.kt
new file mode 100644
index 0000000000..0bbb1c741d
--- /dev/null
+++ b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/ObjectsTest.kt
@@ -0,0 +1,36 @@
+package com.baeldung.kotlin.objects
+
+import org.junit.Assert
+import org.junit.Test
+
+class ObjectsTest {
+    @Test
+    fun singleton() {
+
+        Assert.assertEquals(42, SimpleSingleton.answer)
+        Assert.assertEquals("Hello, world!", SimpleSingleton.greet("world"))
+    }
+
+    @Test
+    fun counter() {
+        Assert.assertEquals(0, Counter.currentCount())
+        Counter.increment()
+        Assert.assertEquals(1, Counter.currentCount())
+        Counter.decrement()
+        Assert.assertEquals(0, Counter.currentCount())
+    }
+
+    @Test
+    fun comparator() {
+        val strings = listOf("Hello", "World")
+        val sortedStrings = strings.sortedWith(ReverseStringComparator)
+
+        Assert.assertEquals(listOf("World", "Hello"), sortedStrings)
+    }
+
+    @Test
+    fun companion() {
+        Assert.assertEquals("You can see me", OuterClass.public)
+        // Assert.assertEquals("You can't see me", OuterClass.secret) // Cannot access 'secret'
+    }
+}
diff --git a/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/OuterClass.kt b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/OuterClass.kt
new file mode 100644
index 0000000000..4abb7a668d
--- /dev/null
+++ b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/OuterClass.kt
@@ -0,0 +1,10 @@
+package com.baeldung.kotlin.objects
+
+class OuterClass {
+    companion object {
+        private val secret = "You can't see me"
+        val public = "You can see me"
+    }
+
+    fun getSecretValue() = secret
+}
diff --git a/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/ReverseStringComparator.kt b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/ReverseStringComparator.kt
new file mode 100644
index 0000000000..20dc2d8c5b
--- /dev/null
+++ b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/ReverseStringComparator.kt
@@ -0,0 +1,5 @@
+package com.baeldung.kotlin.objects
+
+object ReverseStringComparator : Comparator<String> {
+    override fun compare(o1: String, o2: String) = o1.reversed().compareTo(o2.reversed())
+}
diff --git a/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/SimpleSingleton.kt b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/SimpleSingleton.kt
new file mode 100644
index 0000000000..bfafd8183f
--- /dev/null
+++ b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/SimpleSingleton.kt
@@ -0,0 +1,7 @@
+package com.baeldung.kotlin.objects
+
+object SimpleSingleton {
+    val answer = 42;
+
+    fun greet(name: String) = "Hello, $name!"
+}
diff --git a/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/StaticClass.kt b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/StaticClass.kt
new file mode 100644
index 0000000000..36cd476110
--- /dev/null
+++ b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/objects/StaticClass.kt
@@ -0,0 +1,8 @@
+package com.baeldung.kotlin.objects
+
+class StaticClass {
+    companion object {
+        @JvmStatic
+        val staticField = 42
+    }
+}