Nullable Array.contentEquals/contentHashCode/contentToString #KT-34161

libraries/stdlib/jvm/test/collections/ArraysJVMTest.kt

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package test.collections
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+import java.util.Collections
+
+
+class ArraysJVMTest {
+
+    @Suppress("HasPlatformType", "UNCHECKED_CAST")
+    fun <T> platformNull() = Collections.singletonList(null as T).first()
+
+    @Test
+    fun contentEquals() {
+        assertTrue(platformNull<IntArray>() contentEquals null)
+        assertTrue(null contentEquals platformNull<LongArray>())
+
+        assertFalse(platformNull<Array<String>>() contentEquals emptyArray<String>())
+        assertFalse(arrayOf("a", "b") contentEquals platformNull<Array<String>>())
+
+        assertFalse(platformNull<UShortArray>() contentEquals ushortArrayOf())
+        assertFalse(ubyteArrayOf() contentEquals platformNull<UByteArray>())
+    }
+
+    @Test
+    fun contentHashCode() {
+        assertEquals(0, platformNull<Array<Int>>().contentHashCode())
+        assertEquals(0, platformNull<CharArray>().contentHashCode())
+        assertEquals(0, platformNull<ShortArray>().contentHashCode())
+        assertEquals(0, platformNull<BooleanArray>().contentHashCode())
+        assertEquals(0, platformNull<UByteArray>().contentHashCode())
+        assertEquals(0, platformNull<UIntArray>().contentHashCode())
+    }
+
+    @Test
+    fun contentToString() {
+        assertEquals("null", platformNull<Array<String>>().contentToString())
+        assertEquals("null", platformNull<CharArray>().contentToString())
+        assertEquals("null", platformNull<DoubleArray>().contentToString())
+        assertEquals("null", platformNull<FloatArray>().contentToString())
+        assertEquals("null", platformNull<ULongArray>().contentToString())
+    }
+
+    @Test
+    fun contentDeepEquals() {
+        assertFalse(platformNull<Array<String>>() contentDeepEquals emptyArray<String>())
+        assertFalse(arrayOf("a", "b") contentDeepEquals platformNull<Array<String>>())
+    }
+
+    @Test
+    fun contentDeepHashCode() {
+        assertEquals(0, platformNull<Array<Int>>().contentDeepHashCode())
+    }
+
+    @Test
+    fun contentDeepToString() {
+        assertEquals("null", platformNull<Array<String>>().contentDeepToString())
+    }
+}