nits and nats

Author: tarrinneal

packages/pigeon/example/app/lib/src/event_channel_messages.g.dart

@@ -8,6 +8,7 @@
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List;
+
 import 'package:flutter/services.dart';
 import 'package:meta/meta.dart' show immutable, protected, visibleForTesting;
 

packages/pigeon/example/app/lib/src/messages.g.dart

@@ -8,6 +8,7 @@
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List;
+
 import 'package:flutter/services.dart';
 import 'package:meta/meta.dart' show immutable, protected, visibleForTesting;
 

packages/pigeon/lib/src/ast.dart

@@ -528,20 +528,23 @@ class TypeDeclaration {
 
   /// Returns the full annotated name of the type.
   String getFullName({bool withNullable = true}) {
-    if (baseName == 'List' || baseName == 'Map') {
-      return '$baseName<$typeArgumentsString>${isNullable && withNullable ? '?' : ''}';
-    }
-    return '$baseName${isNullable && withNullable ? '?' : ''}';
+    return '$baseName$typeArgumentsString${isNullable && withNullable ? '?' : ''}';
   }
 
   /// Returns the Type Arguments in annotation form.
   String get typeArgumentsString {
+    var typeArgumentString = '<';
     if (baseName == 'List') {
-      return typeArguments.firstOrNull?.getFullName() ?? 'Object?';
+      typeArgumentString +=
+          typeArguments.firstOrNull?.getFullName() ?? 'Object?';
     } else if (baseName == 'Map') {
-      return '${typeArguments.firstOrNull?.getFullName() ?? 'Object?'}, ${typeArguments.lastOrNull?.getFullName() ?? 'Object?'}';
+      typeArgumentString +=
+          '${typeArguments.firstOrNull?.getFullName() ?? 'Object?'}, ${typeArguments.lastOrNull?.getFullName() ?? 'Object?'}';
+    } else {
+      return '';
     }
-    return '';
+    typeArgumentString += '>';
+    return typeArgumentString;
   }
 
   @override

packages/pigeon/lib/src/dart/dart_generator.dart

@@ -768,6 +768,7 @@ class DartGenerator extends StructuredGenerator<InternalDartOptions> {
     indent.writeln(
       "import 'dart:typed_data' show ${typedDataClasses.join(', ')};",
     );
+    indent.newln();
     if (generatorOptions.useFfi) {
       indent.writeln("import 'package:ffi/ffi.dart';");
     }

packages/pigeon/lib/src/generator_tools.dart

@@ -913,16 +913,40 @@ String wrapConditionally(String toWrap, String start, String end, bool wrap) {
   return wrap ? '$start$toWrap$end' : toWrap;
 }
 
-/// Sorts collections by how generic they are.
-int sortByObjectCount(TypeDeclaration a, TypeDeclaration b) {
-  var aTotal = 0;
-  var bTotal = 0;
+/// Compares [TypeDeclaration]s by how generic they are.
+///
+/// Generic-ness is approximated by counting the number of "Objects" and "?" in the
+/// type name, with "Object" being strongly weighted and "?" less so.
+int compareTypeDeclarationGenericness(TypeDeclaration a, TypeDeclaration b) {
+  return _calculateGenericScore(a, 0).compareTo(_calculateGenericScore(b, 0));
+}
+
+int _calculateGenericScore(TypeDeclaration type, int depth) {
+  var score = 0;
 
-  aTotal += a.getFullName(withNullable: false).split('?').length;
-  bTotal += b.getFullName(withNullable: false).split('?').length;
+  if (type.baseName == 'Object') {
+    score += 10000 >> depth;
+  }
+  if (type.isNullable) {
+    score += 1000 >> depth;
+  }
 
-  aTotal += a.getFullName(withNullable: false).split('Object').length * 100;
-  bTotal += b.getFullName(withNullable: false).split('Object').length * 100;
+  // Handle untyped collections by scoring their implicit 'Object?' arguments
+  if (type.typeArguments.isEmpty) {
+    if (type.baseName == 'List') {
+      score += 11000 >> (depth + 1);
+    }
+    if (type.baseName == 'Map') {
+      score += 22000 >> (depth + 1);
+    }
+  }
 
-  return aTotal < bTotal ? -1 : 1;
+  for (final TypeDeclaration arg in type.typeArguments) {
+    score += _calculateGenericScore(arg, depth + 1);
+  }
+  return score;
 }
+
+/// Alias for [compareTypeDeclarationGenericness] to maintain compatibility.
+const int Function(TypeDeclaration, TypeDeclaration) sortByObjectCount =
+    compareTypeDeclarationGenericness;