add kotlin equality and tests

packages/pigeon/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 25.2.0
+
+* [kotlin] Adds equality methods to generated data classes.
+
 ## 25.1.0
 
 * [dart] Adds equality methods to generated data classes.

packages/pigeon/example/app/android/app/src/main/kotlin/dev/flutter/pigeon_example_app/EventChannelMessages.g.kt

@@ -31,6 +31,18 @@ data class IntEvent(val data: Long) : PlatformEvent() {
         data,
     )
   }
+
+  override fun equals(other: Any?): Boolean {
+    if (other !is IntEvent) {
+      return false
+    }
+    if (this === other) {
+      return true
+    }
+    return data == other.data
+  }
+
+  override fun hashCode(): Int = toList().hashCode()
 }
 
 /** Generated class from Pigeon that represents data sent in messages. */
@@ -47,6 +59,18 @@ data class StringEvent(val data: String) : PlatformEvent() {
         data,
     )
   }
+
+  override fun equals(other: Any?): Boolean {
+    if (other !is StringEvent) {
+      return false
+    }
+    if (this === other) {
+      return true
+    }
+    return data == other.data
+  }
+
+  override fun hashCode(): Int = toList().hashCode()
 }
 
 private open class EventChannelMessagesPigeonCodec : StandardMessageCodec() {

packages/pigeon/example/app/android/app/src/main/kotlin/dev/flutter/pigeon_example_app/Messages.g.kt

@@ -46,6 +46,29 @@ class FlutterError(
     val details: Any? = null
 ) : Throwable()
 
+private fun deepEqualsMessages(a: Any?, b: Any?): Boolean {
+  if (a is ByteArray && b is ByteArray) {
+    return a.contentEquals(b)
+  }
+  if (a is IntArray && b is IntArray) {
+    return a.contentEquals(b)
+  }
+  if (a is LongArray && b is LongArray) {
+    return a.contentEquals(b)
+  }
+  if (a is DoubleArray && b is DoubleArray) {
+    return a.contentEquals(b)
+  }
+  if (a is Array<*> && b is Array<*>) {
+    return a.size == b.size && a.indices.all { deepEqualsMessages(a[it], b[it]) }
+  }
+  if (a is Map<*, *> && b is Map<*, *>) {
+    return a.size == b.size &&
+        a.keys.all { (b as Map<Any?, Any?>).containsKey(it) && deepEqualsMessages(a[it], b[it]) }
+  }
+  return a == b
+}
+
 enum class Code(val raw: Int) {
   ONE(0),
   TWO(1);
@@ -82,6 +105,21 @@ data class MessageData(
         data,
     )
   }
+
+  override fun equals(other: Any?): Boolean {
+    if (other !is MessageData) {
+      return false
+    }
+    if (this === other) {
+      return true
+    }
+    return name == other.name &&
+        description == other.description &&
+        code == other.code &&
+        deepEqualsMessages(data, other.data)
+  }
+
+  override fun hashCode(): Int = toList().hashCode()
 }
 
 private open class MessagesPigeonCodec : StandardMessageCodec() {

packages/pigeon/lib/src/generator_tools.dart

@@ -14,7 +14,7 @@ import 'ast.dart';
 /// The current version of pigeon.
 ///
 /// This must match the version in pubspec.yaml.
-const String pigeonVersion = '25.1.0';
+const String pigeonVersion = '25.2.0';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {

packages/pigeon/lib/src/kotlin/kotlin_generator.dart

@@ -291,9 +291,48 @@ class KotlinGenerator extends StructuredGenerator<InternalKotlinOptions> {
         classDefinition,
         dartPackageName: dartPackageName,
       );
+      writeClassEquality(
+        generatorOptions,
+        root,
+        indent,
+        classDefinition,
+        dartPackageName: dartPackageName,
+      );
     });
   }
 
+  @override
+  void writeClassEquality(
+    InternalKotlinOptions generatorOptions,
+    Root root,
+    Indent indent,
+    Class classDefinition, {
+    required String dartPackageName,
+  }) {
+    indent.writeScoped('override fun equals(other: Any?): Boolean {', '}', () {
+      indent.writeScoped('if (other !is ${classDefinition.name}) {', '}', () {
+        indent.writeln('return false');
+      });
+      indent.writeScoped('if (this === other) {', '}', () {
+        indent.writeln('return true');
+      });
+      indent.write('return ');
+      indent.format(classDefinition.fields
+          .map((NamedType field) => field.type.baseName == 'List' ||
+                  field.type.baseName == 'Float64List' ||
+                  field.type.baseName == 'Int32List' ||
+                  field.type.baseName == 'Int64List' ||
+                  field.type.baseName == 'Uint8List' ||
+                  field.type.baseName == 'Map'
+              ? 'deepEquals${generatorOptions.fileSpecificClassNameComponent}(${field.name}, other.${field.name})'
+              : '${field.name} == other.${field.name}')
+          .join('\n&& '));
+    });
+
+    indent.newln();
+    indent.writeln('override fun hashCode(): Int = toList().hashCode()');
+  }
+
   void _writeDataClassSignature(
     Indent indent,
     Class classDefinition, {
@@ -507,7 +546,7 @@ class KotlinGenerator extends StructuredGenerator<InternalKotlinOptions> {
     indent.newln();
     if (root.containsEventChannel) {
       indent.writeln(
-          'val ${generatorOptions.fileSpecificClassNameComponent}$_pigeonMethodChannelCodec = StandardMethodCodec(${generatorOptions.fileSpecificClassNameComponent}$_codecName());');
+          'val ${generatorOptions.fileSpecificClassNameComponent}$_pigeonMethodChannelCodec = StandardMethodCodec(${generatorOptions.fileSpecificClassNameComponent}$_codecName())');
       indent.newln();
     }
   }
@@ -1219,6 +1258,36 @@ if (wrapped == null) {
     });
   }
 
+  void _writeDeepEquals(InternalKotlinOptions generatorOptions, Indent indent) {
+    indent.format('''
+private fun deepEquals${generatorOptions.fileSpecificClassNameComponent}(a: Any?, b: Any?): Boolean {
+  if (a is ByteArray && b is ByteArray) {
+      return a.contentEquals(b)
+  }
+  if (a is IntArray && b is IntArray) {
+      return a.contentEquals(b)
+  }
+  if (a is LongArray && b is LongArray) {
+      return a.contentEquals(b)
+  }
+  if (a is DoubleArray && b is DoubleArray) {
+      return a.contentEquals(b)
+  }
+  if (a is Array<*> && b is Array<*>) {
+    return a.size == b.size &&
+        a.indices.all{ deepEquals${generatorOptions.fileSpecificClassNameComponent}(a[it], b[it]) }
+  }
+  if (a is Map<*, *> && b is Map<*, *>) {
+    return a.size == b.size && a.keys.all {
+        (b as Map<Any?, Any?>).containsKey(it) &&
+        deepEquals${generatorOptions.fileSpecificClassNameComponent}(a[it], b[it])
+    }
+  }
+  return a == b;
+}
+    ''');
+  }
+
   @override
   void writeGeneralUtilities(
     InternalKotlinOptions generatorOptions,
@@ -1236,6 +1305,13 @@ if (wrapped == null) {
     if (generatorOptions.includeErrorClass) {
       _writeErrorClass(generatorOptions, indent);
     }
+    if (root.classes.isNotEmpty &&
+        root.classes.any((Class dataClass) => dataClass.fields.any(
+            (NamedType field) =>
+                field.type.baseName.startsWith('List') ||
+                field.type.baseName.startsWith('Map')))) {
+      _writeDeepEquals(generatorOptions, indent);
+    }
   }
 
   static void _writeMethodDeclaration(