fix record level hooks

Author: dickermoshe

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/records/mappable_record_test.dart

@@ -1,3 +1,5 @@
+import 'dart:math';
+
 import 'package:dart_mappable/dart_mappable.dart';
 import 'package:test/test.dart';
 
@@ -19,6 +21,22 @@ 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;
@@ -66,5 +84,19 @@ void main() {
       expect(p, equals((x: 1, y: 2)));
       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)}),
+      );
+    });
   });
 }

packages/dart_mappable/test/records/mappable_record_test.mapper.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_builder/CHANGELOG.md

@@ -1,7 +1,9 @@
+import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element2.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:collection/collection.dart';
 
+import '../../utils.dart';
 import '../mapper_element.dart';
 
 abstract class RecordMapperElement<T extends Element2>
@@ -48,4 +50,19 @@ abstract class RecordMapperElement<T extends Element2>
   String genericArgAt(int index) {
     return String.fromCharCode('A'.codeUnitAt(0) + index);
   }
+
+  late final String? hookForRecord = () {
+    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/record/record_mapper_element.dart

@@ -32,6 +32,7 @@ class RecordMapperGenerator extends MapperGenerator<RecordMapperElement> {
 
     generateTypeFactory(output);
     generateApplyOverride(output);
+    generateHook(output);
     generateInstantiate(output);
     generateStaticDecoders(output);
 
@@ -120,4 +121,14 @@ class RecordMapperGenerator extends MapperGenerator<RecordMapperElement> {
       '  }\n',
     );
   }
+
+  void generateHook(StringBuffer output) {
+    var hook = element.hookForRecord;
+    if (hook != null) {
+      output.write('''
+        @override
+        final MappingHook hook = $hook;
+      ''');
+    }
+  }
 }