Locale-agnostic case conversions by default #KT-43023

libraries/stdlib/test/collections/ArraysTest.kt

@@ -1369,7 +1369,7 @@ class ArraysTest {
         assertEquals(mapOf("Alice" to 5, "Bob" to 3, "Carol" to 5), itemsWithTheirLength)
 
         val updatedLength = items.copyOfRange(1, 3)
-            .associateWithTo(itemsWithTheirLength.toMutableMap()) { name -> name.toLowerCase().count { it in "aeuio" } }
+            .associateWithTo(itemsWithTheirLength.toMutableMap()) { name -> name.lowercase().count { it in "aeuio" } }
 
         assertEquals(mapOf("Alice" to 5, "Bob" to 1, "Carol" to 2), updatedLength)
     }

libraries/stdlib/test/collections/CollectionTest.kt

@@ -489,7 +489,7 @@ class CollectionTest {
         assertEquals(mapOf("Alice" to 5, "Bob" to 3, "Carol" to 5), itemsWithTheirLength)
 
         val updatedLength =
-            items.drop(1).associateWithTo(itemsWithTheirLength.toMutableMap()) { name -> name.toLowerCase().count { it in "aeuio" }}
+            items.drop(1).associateWithTo(itemsWithTheirLength.toMutableMap()) { name -> name.lowercase().count { it in "aeuio" }}
 
         assertEquals(mapOf("Alice" to 5, "Bob" to 1, "Carol" to 2), updatedLength)
     }
@@ -1099,7 +1099,7 @@ class CollectionTest {
     }
 
     @Test fun sortedWith() {
-        val comparator = compareBy<String> { it.toUpperCase().reversed() }
+        val comparator = compareBy<String> { it.uppercase().reversed() }
         val data = listOf("cat", "dad", "BAD")
 
         expect(listOf("BAD", "dad", "cat")) { data.sortedWith(comparator) }

libraries/stdlib/test/collections/IterableTests.kt

@@ -485,7 +485,7 @@ abstract class IterableTests<T : Iterable<String>>(val createFrom: (Array<out St
 
     @Test
     fun mapAndJoinToString() {
-        val result = data.joinToString(separator = "-") { it.toUpperCase() }
+        val result = data.joinToString(separator = "-") { it.uppercase() }
         assertEquals("FOO-BAR", result)
     }
 

libraries/stdlib/test/collections/MapTest.kt

@@ -284,7 +284,7 @@ class MapTest {
     }
 
     @Test fun createWithSelectorForKeyAndValue() {
-        val map = listOf("a", "bb", "ccc").associateBy({ it.length }, { it.toUpperCase() })
+        val map = listOf("a", "bb", "ccc").associateBy({ it.length }, { it.uppercase() })
         assertEquals(3, map.size)
         assertEquals("A", map[1])
         assertEquals("BB", map[2])
@@ -292,7 +292,7 @@ class MapTest {
     }
 
     @Test fun createWithPairSelector() {
-        val map = listOf("a", "bb", "ccc").associate { it.length to it.toUpperCase() }
+        val map = listOf("a", "bb", "ccc").associate { it.length to it.uppercase() }
         assertEquals(3, map.size)
         assertEquals("A", map[1])
         assertEquals("BB", map[2])

libraries/stdlib/test/collections/SequenceTest.kt

@@ -718,7 +718,7 @@ public class SequenceTest {
         assertEquals(mapOf("Alice" to 5, "Bob" to 3, "Carol" to 5), itemsWithTheirLength)
 
         val updatedLength =
-            items.drop(1).associateWithTo(itemsWithTheirLength.toMutableMap()) { name -> name.toLowerCase().count { it in "aeuio" }}
+            items.drop(1).associateWithTo(itemsWithTheirLength.toMutableMap()) { name -> name.lowercase().count { it in "aeuio" }}
 
         assertEquals(mapOf("Alice" to 5, "Bob" to 1, "Carol" to 2), updatedLength)
     }