[pigeon] Code clean up

packages/pigeon/CHANGELOG.md

@@ -1,3 +1,9 @@
+## 27.0.0
+
+* **BREAKING CHANGE**: Adds support for acronyms in snake_case conversion in generators. This may change the generated output for symbols containing acronyms.
+* Refactors response handling across all generators to use a single `wrapResponse` method instead of `wrapResult` and `wrapError`.
+* Cleans up repeated code and adds an error class and prologue to the base `Generator` class.
+
 ## 26.3.4
 
 * [kotlin] Updates generated error class to inherit from `RuntimeException`

packages/pigeon/example/app/android/app/src/main/java/io/flutter/plugins/Messages.java

@@ -185,6 +185,38 @@ static int pigeonDeepHashCode(Object value) {
     return value.hashCode();
   }
 
+  @NonNull
+  protected static ArrayList<Object> wrapResponse(
+      @Nullable Object result, @Nullable Throwable error) {
+    ArrayList<Object> response = new ArrayList<>();
+    if (error != null) {
+      if (error instanceof FlutterError) {
+        FlutterError flutterError = (FlutterError) error;
+        response.add(flutterError.code);
+        response.add(flutterError.getMessage());
+        response.add(flutterError.details);
+      } else {
+        response.add(error.toString());
+        response.add(error.getClass().getSimpleName());
+        response.add(
+            "Cause: " + error.getCause() + ", Stacktrace: " + Log.getStackTraceString(error));
+      }
+    } else {
+      response.add(result);
+    }
+    return response;
+  }
+
+  @NonNull
+  protected static FlutterError createConnectionError(@NonNull String channelName) {
+    return new FlutterError(
+        "channel-error", "Unable to establish connection on channel: " + channelName + ".", "");
+  }
+
+  @Target(METHOD)
+  @Retention(CLASS)
+  @interface CanIgnoreReturnValue {}
+
   /** Error class for passing custom error details to Flutter via a thrown PlatformException. */
   public static class FlutterError extends RuntimeException {
 
@@ -201,33 +233,6 @@ public FlutterError(@NonNull String code, @Nullable String message, @Nullable Ob
     }
   }
 
-  @NonNull
-  protected static ArrayList<Object> wrapError(@NonNull Throwable exception) {
-    ArrayList<Object> errorList = new ArrayList<>(3);
-    if (exception instanceof FlutterError) {
-      FlutterError error = (FlutterError) exception;
-      errorList.add(error.code);
-      errorList.add(error.getMessage());
-      errorList.add(error.details);
-    } else {
-      errorList.add(exception.toString());
-      errorList.add(exception.getClass().getSimpleName());
-      errorList.add(
-          "Cause: " + exception.getCause() + ", Stacktrace: " + Log.getStackTraceString(exception));
-    }
-    return errorList;
-  }
-
-  @NonNull
-  protected static FlutterError createConnectionError(@NonNull String channelName) {
-    return new FlutterError(
-        "channel-error", "Unable to establish connection on channel: " + channelName + ".", "");
-  }
-
-  @Target(METHOD)
-  @Retention(CLASS)
-  @interface CanIgnoreReturnValue {}
-
   public enum Code {
     ONE(0),
     TWO(1);
@@ -472,14 +477,12 @@ static void setUp(
         if (api != null) {
           channel.setMessageHandler(
               (message, reply) -> {
-                ArrayList<Object> wrapped = new ArrayList<>();
                 try {
                   String output = api.getHostLanguage();
-                  wrapped.add(0, output);
+                  reply.reply(wrapResponse(output, null));
                 } catch (Throwable exception) {
-                  wrapped = wrapError(exception);
+                  reply.reply(wrapResponse(null, exception));
                 }
-                reply.reply(wrapped);
               });
         } else {
           channel.setMessageHandler(null);
@@ -495,17 +498,15 @@ static void setUp(
         if (api != null) {
           channel.setMessageHandler(
               (message, reply) -> {
-                ArrayList<Object> wrapped = new ArrayList<>();
                 ArrayList<Object> args = (ArrayList<Object>) message;
                 Long aArg = (Long) args.get(0);
                 Long bArg = (Long) args.get(1);
                 try {
                   Long output = api.add(aArg, bArg);
-                  wrapped.add(0, output);
+                  reply.reply(wrapResponse(output, null));
                 } catch (Throwable exception) {
-                  wrapped = wrapError(exception);
+                  reply.reply(wrapResponse(null, exception));
                 }
-                reply.reply(wrapped);
               });
         } else {
           channel.setMessageHandler(null);
@@ -521,19 +522,16 @@ static void setUp(
         if (api != null) {
           channel.setMessageHandler(
               (message, reply) -> {
-                ArrayList<Object> wrapped = new ArrayList<>();
                 ArrayList<Object> args = (ArrayList<Object>) message;
                 MessageData messageArg = (MessageData) args.get(0);
                 Result<Boolean> resultCallback =
                     new Result<Boolean>() {
                       public void success(Boolean result) {
-                        wrapped.add(0, result);
-                        reply.reply(wrapped);
+                        reply.reply(wrapResponse(result, null));
                       }
 
                       public void error(Throwable error) {
-                        ArrayList<Object> wrappedError = wrapError(error);
-                        reply.reply(wrappedError);
+                        reply.reply(wrapResponse(null, error));
                       }
                     };
 

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

@@ -20,18 +20,18 @@ private object MessagesPigeonUtils {
         "channel-error", "Unable to establish connection on channel: '$channelName'.", "")
   }
 
-  fun wrapResult(result: Any?): List<Any?> {
-    return listOf(result)
-  }
-
-  fun wrapError(exception: Throwable): List<Any?> {
-    return if (exception is FlutterError) {
-      listOf(exception.code, exception.message, exception.details)
+  fun wrapResponse(result: Any?, error: Throwable?): List<Any?> {
+    return if (error != null) {
+      if (error is FlutterError) {
+        listOf(error.code, error.message, error.details)
+      } else {
+        listOf(
+            error.javaClass.simpleName,
+            error.toString(),
+            "Cause: " + error.cause + ", Stacktrace: " + Log.getStackTraceString(error))
+      }
     } else {
-      listOf(
-          exception.javaClass.simpleName,
-          exception.toString(),
-          "Cause: " + exception.cause + ", Stacktrace: " + Log.getStackTraceString(exception))
+      listOf(result)
     }
   }
 
@@ -312,9 +312,9 @@ interface ExampleHostApi {
           channel.setMessageHandler { _, reply ->
             val wrapped: List<Any?> =
                 try {
-                  listOf(api.getHostLanguage())
+                  MessagesPigeonUtils.wrapResponse(api.getHostLanguage(), null)
                 } catch (exception: Throwable) {
-                  MessagesPigeonUtils.wrapError(exception)
+                  MessagesPigeonUtils.wrapResponse(null, exception)
                 }
             reply.reply(wrapped)
           }
@@ -335,9 +335,9 @@ interface ExampleHostApi {
             val bArg = args[1] as Long
             val wrapped: List<Any?> =
                 try {
-                  listOf(api.add(aArg, bArg))
+                  MessagesPigeonUtils.wrapResponse(api.add(aArg, bArg), null)
                 } catch (exception: Throwable) {
-                  MessagesPigeonUtils.wrapError(exception)
+                  MessagesPigeonUtils.wrapResponse(null, exception)
                 }
             reply.reply(wrapped)
           }
@@ -358,10 +358,10 @@ interface ExampleHostApi {
             api.sendMessage(messageArg) { result: Result<Boolean> ->
               val error = result.exceptionOrNull()
               if (error != null) {
-                reply.reply(MessagesPigeonUtils.wrapError(error))
+                reply.reply(MessagesPigeonUtils.wrapResponse(null, error))
               } else {
                 val data = result.getOrNull()
-                reply.reply(MessagesPigeonUtils.wrapResult(data))
+                reply.reply(MessagesPigeonUtils.wrapResponse(data, null))
               }
             }
           }

packages/pigeon/example/app/ios/Runner/Messages.g.swift

@@ -14,48 +14,30 @@ import Foundation
   #error("Unsupported platform.")
 #endif
 
-/// Error class for passing custom error details to Dart side.
-final class PigeonError: Error {
-  let code: String
-  let message: String?
-  let details: Sendable?
-
-  init(code: String, message: String?, details: Sendable?) {
-    self.code = code
-    self.message = message
-    self.details = details
-  }
-
-  var localizedDescription: String {
-    return
-      "PigeonError(code: \(code), message: \(message ?? "<nil>"), details: \(details ?? "<nil>")"
-  }
-}
-
-private func wrapResult(_ result: Any?) -> [Any?] {
-  return [result]
-}
-
-private func wrapError(_ error: Any) -> [Any?] {
-  if let pigeonError = error as? PigeonError {
-    return [
-      pigeonError.code,
-      pigeonError.message,
-      pigeonError.details,
-    ]
-  }
-  if let flutterError = error as? FlutterError {
+private func wrapResponse(_ result: Any?, _ error: Any?) -> [Any?] {
+  if let error = error {
+    if let pigeonError = error as? PigeonError {
+      return [
+        pigeonError.code,
+        pigeonError.message,
+        pigeonError.details,
+      ]
+    }
+    if let flutterError = error as? FlutterError {
+      return [
+        flutterError.code,
+        flutterError.message,
+        flutterError.details,
+      ]
+    }
     return [
-      flutterError.code,
-      flutterError.message,
-      flutterError.details,
+      "\(error)",
+      "\(Swift.type(of: error))",
+      "Stacktrace: \(Thread.callStackSymbols)",
     ]
+  } else {
+    return [result]
   }
-  return [
-    "\(error)",
-    "\(Swift.type(of: error))",
-    "Stacktrace: \(Thread.callStackSymbols)",
-  ]
 }
 
 private func createConnectionError(withChannelName channelName: String) -> PigeonError {
@@ -182,6 +164,24 @@ func deepHashMessages(value: Any?, hasher: inout Hasher) {
   }
 }
 
+/// Error class for passing custom error details to Dart side.
+final class PigeonError: Error {
+  let code: String
+  let message: String?
+  let details: Sendable?
+
+  init(code: String, message: String?, details: Sendable?) {
+    self.code = code
+    self.message = message
+    self.details = details
+  }
+
+  var localizedDescription: String {
+    return
+      "PigeonError(code: \(code), message: \(message ?? "<nil>"), details: \(details ?? "<nil>")"
+  }
+}
+
 enum Code: Int {
   case one = 0
   case two = 1
@@ -302,9 +302,9 @@ class ExampleHostApiSetup {
       getHostLanguageChannel.setMessageHandler { _, reply in
         do {
           let result = try api.getHostLanguage()
-          reply(wrapResult(result))
+          reply(wrapResponse(result, nil))
         } catch {
-          reply(wrapError(error))
+          reply(wrapResponse(nil, error))
         }
       }
     } else {
@@ -320,9 +320,9 @@ class ExampleHostApiSetup {
         let bArg = args[1] as! Int64
         do {
           let result = try api.add(aArg, to: bArg)
-          reply(wrapResult(result))
+          reply(wrapResponse(result, nil))
         } catch {
-          reply(wrapError(error))
+          reply(wrapResponse(nil, error))
         }
       }
     } else {
@@ -338,9 +338,9 @@ class ExampleHostApiSetup {
         api.sendMessage(message: messageArg) { result in
           switch result {
           case .success(let res):
-            reply(wrapResult(res))
+            reply(wrapResponse(res, nil))
           case .failure(let error):
-            reply(wrapError(error))
+            reply(wrapResponse(nil, error))
           }
         }
       }

packages/pigeon/example/app/linux/messages.g.cc

@@ -1008,7 +1008,9 @@ pigeon_example_package_message_flutter_api_flutter_method_response_new(
     self->error = fl_value_ref(response);
   } else {
     FlValue* value = fl_value_get_list_value(response, 0);
-    self->return_value = fl_value_ref(value);
+    if (value != nullptr) {
+      self->return_value = fl_value_ref(value);
+    }
   }
   return self;
 }