fix record level hooks (#311)

Co-authored-by: Moshe Dicker <dickermoshe@gmail.com>

Author: schultek

packages/dart_mappable/CHANGELOG.md

@@ -1,3 +1,7 @@
+# Unreleased
+
+- Record mappers now correctly generate hooks specified on the record annotation itself, not just those on individual fields.
+
 # 4.6.0
 
 - Add support for self-referencing generics (e.g. `T extends Comparable<T>`)

packages/dart_mappable/test/initializer/init_package_test.init.dart

@@ -1,3 +1,5 @@
+import 'dart:math';
+
 import 'package:dart_mappable/dart_mappable.dart';
 import 'package:test/test.dart';
 
@@ -22,6 +24,22 @@ class RoundingHook extends MappingHook {
   }
 }
 
+class HypotenuseHook extends MappingHook {
+  const HypotenuseHook();
+
+  @override
+  Object? beforeDecode(Object? value) {
+    final map = (value as Map).cast<String, dynamic>();
+    final leg1 = map['x'] as num;
+    final leg2 = map['y'] as num;
+    map['hypotenuse'] = sqrt(leg1 * leg1 + leg2 * leg2);
+    return map;
+  }
+}
+
+@MappableRecord(hook: HypotenuseHook())
+typedef Hypotenuse = ({double x, double y, double hypotenuse});
+
 @MappableClass()
 class Location with LocationMappable {
   final Point point;
@@ -70,6 +88,20 @@ void main() {
       expect(encode(p), equals({'a': 1, 'y': 2}));
     });
 
+    test('can decode and encode record hook on record', () {
+      var decode = MapperContainer.globals.fromMap;
+      var encode = MapperContainer.globals.toMap;
+
+      HypotenuseMapper.ensureInitialized();
+
+      var h = decode<Hypotenuse>({'x': 3, 'y': 4});
+      expect(h, equals((x: 3, y: 4, hypotenuse: sqrt(3 * 3 + 4 * 4))));
+      expect(
+        encode(h),
+        equals({'x': 3, 'y': 4, 'hypotenuse': sqrt(3 * 3 + 4 * 4)}),
+      );
+    });
+
     test('can decode and encode nested record', () {
       var decode = MapperContainer.globals.fromMap;
       var encode = MapperContainer.globals.toMap;

packages/dart_mappable/test/records/mappable_record_test.dart

@@ -1,3 +1,7 @@
+# Unreleased
+
+- Record mappers now correctly generate hooks specified on the record annotation itself, not just those on individual fields.
+
 # 4.6.0
 
 - Migrate to new `element2` analyzer model.

packages/dart_mappable/test/records/mappable_record_test.mapper.dart

@@ -1,4 +1,3 @@
-import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:dart_mappable/dart_mappable.dart';
 
@@ -76,21 +75,6 @@ abstract class ClassMapperElement extends InterfaceMapperElement<ClassElement>
       options.generateMethods ??
       GenerateMethods.all;
 
-  late final String? hookForClass = () {
-    var hook = annotation.value?.read('hook');
-    if (hook != null && !hook.isNull) {
-      var node = annotation.getPropertyNode('hook');
-      if (node != null) {
-        var hook = node.toSource();
-        if (node is InstanceCreationExpression) {
-          hook = 'const $hook';
-        }
-        return hook;
-      }
-    }
-    return null;
-  }();
-
   // --- Element properties ---
 
   @override

packages/dart_mappable_builder/CHANGELOG.md

@@ -67,4 +67,19 @@ abstract class InterfaceMapperElement<T extends Element>
   String get typeParamsDeclaration;
 
   List<MapperFieldElement> get fields;
+
+  late final String? hookForElement = () {
+    var hook = annotation.value?.read('hook');
+    if (hook != null && !hook.isNull) {
+      var node = annotation.getPropertyNode('hook');
+      if (node != null) {
+        var hook = node.toSource();
+        if (node is InstanceCreationExpression) {
+          hook = 'const $hook';
+        }
+        return hook;
+      }
+    }
+    return null;
+  }();
 }

packages/dart_mappable_builder/lib/src/elements/class/class_mapper_element.dart

@@ -9,7 +9,7 @@ mixin DecodingMixin on MapperGenerator<TargetClassMapperElement> {
   Future<void> generateInstantiateMethod(StringBuffer output) async {
     output.write('\n');
 
-    var hook = element.hookForClass;
+    var hook = element.hookForElement;
     if (hook != null) {
       output.write('''
         @override
@@ -89,7 +89,7 @@ mixin DecodingMixin on MapperGenerator<TargetClassMapperElement> {
     if (element.superElement == null) {
       return [];
     } else {
-      var hook = element.superElement!.hookForClass;
+      var hook = element.superElement!.hookForElement;
       return [if (hook != null) hook, ..._getSuperHooks(element.superElement!)];
     }
   }

packages/dart_mappable_builder/lib/src/elements/mapper_element.dart

@@ -42,6 +42,7 @@ class RecordMapperGenerator extends MapperGenerator<RecordMapperElement> {
 
     generateTypeFactory(output);
     generateApplyOverride(output);
+    generateHook(output);
     generateInstantiate(output);
     generateStaticDecoders(output);
 
@@ -130,4 +131,14 @@ class RecordMapperGenerator extends MapperGenerator<RecordMapperElement> {
       '  }\n',
     );
   }
+
+  void generateHook(StringBuffer output) {
+    var hook = element.hookForElement;
+    if (hook != null) {
+      output.write('''
+        @override
+        final MappingHook hook = $hook;
+      ''');
+    }
+  }
 }