feat(kotlin_generator.dart, enum.dart, enum.gen.dart, EnumTest.kt): a…

…dd SnakeCase enum member to EnumState

refactor(kotlin_generator.dart): simplify nameScreamingSnakeCase regex replacement logic
test(EnumTest.kt): update test cases to use new SnakeCase enum member for better coverage

packages/pigeon/lib/kotlin_generator.dart

@@ -129,8 +129,7 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
             indent, member.documentationComments, _docCommentSpec);
         final String nameScreamingSnakeCase = member.name
             .replaceAllMapped(
-                RegExp(r'(?<=[a-z])[A-Z]'),
-                (Match m) => '_${m.group(0)}')
+                RegExp(r'(?<=[a-z])[A-Z]'), (Match m) => '_${m.group(0)}')
             .toUpperCase();
         indent.write('$nameScreamingSnakeCase($index)');
         if (index != anEnum.members.length - 1) {

packages/pigeon/pigeons/enum.dart

@@ -18,6 +18,9 @@ enum EnumState {
 
   /// This comment is to test enum member (Error) documentation comments.
   Error,
+
+  /// This comment is to test enum member (SnakeCase) documentation comments.
+  SnakeCase,
 }
 
 /// This comment is to test class documentation comments.

packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/enum.gen.dart

@@ -40,6 +40,9 @@ enum EnumState {
 
   /// This comment is to test enum member (Error) documentation comments.
   Error,
+
+  /// This comment is to test enum member (SnakeCase) documentation comments.
+  SnakeCase,
 }
 
 /// This comment is to test class documentation comments.

packages/pigeon/platform_tests/test_plugin/android/src/test/kotlin/com/example/test_plugin/EnumTest.kt

@@ -21,7 +21,7 @@ internal class EnumTest : TestCase() {
     val api = mockk<EnumApi2Host>()
 
     val channelName = "dev.flutter.pigeon.pigeon_integration_tests.EnumApi2Host.echo"
-    val input = DataWithEnum(EnumState.SUCCESS)
+    val input = DataWithEnum(EnumState.SNAKE_CASE)
 
     val handlerSlot = slot<BinaryMessenger.BinaryMessageHandler>()
 
@@ -52,7 +52,7 @@ internal class EnumTest : TestCase() {
     val binaryMessenger = mockk<BinaryMessenger>()
     val api = EnumApi2Flutter(binaryMessenger)
 
-    val input = DataWithEnum(EnumState.SUCCESS)
+    val input = DataWithEnum(EnumState.SNAKE_CASE)
 
     every { binaryMessenger.send(any(), any(), any()) } answers
         {