Add support for CASE_INSENSITIVE_ORDER in JS and common

#KT-18067

libraries/stdlib/common/src/kotlin/TextH.kt

@@ -187,6 +187,16 @@ expect fun CharSequence.regionMatches(
 ): Boolean
 
 
+/**
+ * A Comparator that orders strings ignoring character case.
+ *
+ * Note that this Comparator does not take locale into account,
+ * and will result in an unsatisfactory ordering for certain locales.
+ */
+@SinceKotlin("1.2")
+public expect val String.Companion.CASE_INSENSITIVE_ORDER: Comparator<String>
+
+
 /**
  * Returns `true` if the contents of this string is equal to the word "true", ignoring case, and `false` otherwise.
  */

libraries/stdlib/js/src/kotlin/string.kt

@@ -105,4 +105,11 @@ public actual fun String.compareTo(other: String, ignoreCase: Boolean = false):
     } else {
         return compareTo(other)
     }
-}
+}
+
+
+private val STRING_CASE_INSENSITIVE_ORDER = Comparator<String> { a, b -> a.compareTo(b, ignoreCase = true) }
+
+@SinceKotlin("1.2")
+public actual val String.Companion.CASE_INSENSITIVE_ORDER: Comparator<String>
+    get() = STRING_CASE_INSENSITIVE_ORDER

libraries/stdlib/jvm/src/kotlin/text/StringsJVM.kt

@@ -466,5 +466,5 @@ public actual fun CharSequence.repeat(n: Int): String {
  * Note that this Comparator does not take locale into account,
  * and will result in an unsatisfactory ordering for certain locales.
  */
-public val String.Companion.CASE_INSENSITIVE_ORDER: Comparator<String>
+public actual val String.Companion.CASE_INSENSITIVE_ORDER: Comparator<String>
     get() = java.lang.String.CASE_INSENSITIVE_ORDER

libraries/stdlib/jvm/test/text/StringJVMTest.kt

@@ -61,11 +61,6 @@ class StringJVMTest {
         assertArrayNotSameButEquals(charArrayOf('\u0000', '\u0000', 'e', 'l'), buffer)
     }
 
-    @Test fun orderIgnoringCase() {
-        val list = listOf("Beast", "Ast", "asterisk")
-        assertEquals(listOf("Ast", "Beast", "asterisk"), list.sorted())
-        assertEquals(listOf("Ast", "asterisk", "Beast"), list.sortedWith(String.CASE_INSENSITIVE_ORDER))
-    }
 
     @Test fun charsets() {
         assertEquals("UTF-32", Charsets.UTF_32.name())

libraries/stdlib/test/text/StringTest.kt

@@ -804,6 +804,12 @@ class StringTest {
     }
 
 
+    @Test fun orderIgnoringCase() {
+        val list = listOf("Beast", "Ast", "asterisk", "[]")
+        assertEquals(listOf("Ast", "Beast", "[]", "asterisk"), list.sorted())
+        assertEquals(listOf("[]", "Ast", "asterisk", "Beast"), list.sortedWith(String.CASE_INSENSITIVE_ORDER))
+    }
+
     @Test fun replace() {
         val input = "abbAb"
         assertEquals("abb${'$'}b", input.replace('A', '$'))