Don't generate const constr for non-const parent

Closes #2735

drift_dev/CHANGELOG.md

@@ -1,5 +1,8 @@
 ## 2.14.0-dev
 
+- Don't generate `const` row classes when they are extending a class which
+  isn't const.
+
 ## 2.13.2
 
 - Fix generated queries relying on custom types.

drift_dev/lib/src/analysis/resolver/dart/helper.dart

@@ -198,7 +198,7 @@ extension TypeUtils on DartType {
 
 class DataClassInformation {
   final String enforcedName;
-  final AnnotatedDartCode? extending;
+  final CustomParentClass? extending;
   final ExistingRowClass? existingClass;
 
   DataClassInformation(
@@ -234,7 +234,7 @@ class DataClassInformation {
     }
 
     String name;
-    AnnotatedDartCode? customParentClass;
+    CustomParentClass? customParentClass;
     ExistingRowClass? existingClass;
 
     if (dataClassName != null) {

drift_dev/lib/src/analysis/resolver/shared/data_class.dart

@@ -1,6 +1,7 @@
 import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
+import 'package:drift_dev/src/analysis/results/result_sets.dart';
 
 import '../../driver/error.dart';
 import '../../results/dart.dart';
@@ -24,7 +25,7 @@ String dataClassNameForClassName(String tableName) {
   return '${tableName}Data';
 }
 
-AnnotatedDartCode? parseCustomParentClass(
+CustomParentClass? parseCustomParentClass(
   String dartTypeName,
   DartObject dataClassName,
   ClassElement element,
@@ -44,7 +45,6 @@ AnnotatedDartCode? parseCustomParentClass(
             'DataClass',
           ),
         );
-        return null;
       }
 
       if (extendingType.typeArguments.length > 1) {
@@ -55,7 +55,22 @@ AnnotatedDartCode? parseCustomParentClass(
             'type parameter',
           ),
         );
-        return null;
+      }
+
+      final defaultConstructor =
+          extendingType.lookUpConstructor(null, element.library);
+      var isConst = true;
+      AnnotatedDartCode code;
+      if (defaultConstructor == null) {
+        resolver.reportError(
+          DriftAnalysisError.forDartElement(
+            element,
+            'Parameter `extending` in @DataClassName must have an unnamed '
+            'constructor.',
+          ),
+        );
+      } else {
+        isConst = defaultConstructor.isConst;
       }
 
       // For legacy reasons, if we're extending an existing class with a type
@@ -64,7 +79,7 @@ AnnotatedDartCode? parseCustomParentClass(
       if (extendingType.typeArguments.length == 1) {
         final genericType = extendingType.typeArguments[0];
         if (genericType.isDartCoreObject || genericType is DynamicType) {
-          return AnnotatedDartCode([
+          code = AnnotatedDartCode([
             DartTopLevelSymbol.topLevelElement(extendingType.element),
             '<',
             DartTopLevelSymbol(dartTypeName, null),
@@ -84,7 +99,8 @@ AnnotatedDartCode? parseCustomParentClass(
         }
       }
 
-      return AnnotatedDartCode.type(extendingType);
+      code = AnnotatedDartCode.type(extendingType);
+      return CustomParentClass(parentClass: code, isConst: isConst);
     } else {
       resolver.reportError(
         DriftAnalysisError.forDartElement(

drift_dev/lib/src/analysis/results/result_sets.dart

@@ -5,6 +5,19 @@ import 'element.dart';
 import 'column.dart';
 import 'dart.dart';
 
+/// Drift allows specifying a base class which the generated row class will then
+/// extend. This class describes the specified parent class along with
+/// additional information needed for code generation.
+class CustomParentClass {
+  final AnnotatedDartCode parentClass;
+  final bool isConst;
+
+  CustomParentClass({
+    required this.parentClass,
+    required this.isConst,
+  });
+}
+
 abstract class DriftElementWithResultSet extends DriftSchemaElement {
   /// The columns declared in this table or view.
   List<DriftColumn> get columns;
@@ -18,7 +31,7 @@ abstract class DriftElementWithResultSet extends DriftSchemaElement {
   ExistingRowClass? get existingRowClass;
 
   /// Class that added to data class as implementation
-  AnnotatedDartCode? get customParentClass;
+  CustomParentClass? get customParentClass;
 
   /// Whether this table has an existing row class, meaning that drift will not
   /// generate one on its own.

drift_dev/lib/src/analysis/results/table.dart

@@ -2,7 +2,6 @@ import 'package:collection/collection.dart';
 import 'package:drift/drift.dart' show DriftSqlType;
 import 'package:sqlparser/sqlparser.dart' as sql;
 
-import 'dart.dart';
 import 'element.dart';
 
 import 'column.dart';
@@ -22,7 +21,7 @@ class DriftTable extends DriftElementWithResultSet {
   final ExistingRowClass? existingRowClass;
 
   @override
-  final AnnotatedDartCode? customParentClass;
+  final CustomParentClass? customParentClass;
 
   /// The fixed [entityInfoName] to use, overriding the default.
   final String? fixedEntityInfoName;

drift_dev/lib/src/analysis/results/view.dart

@@ -14,7 +14,7 @@ class DriftView extends DriftElementWithResultSet {
   final DriftViewSource source;
 
   @override
-  final AnnotatedDartCode? customParentClass;
+  final CustomParentClass? customParentClass;
 
   @override
   String entityInfoName;

drift_dev/lib/src/analysis/serializer.dart

@@ -52,7 +52,8 @@ class ElementSerializer {
           for (final constraint in element.tableConstraints)
             _serializeTableConstraint(constraint),
         ],
-        'custom_parent_class': element.customParentClass?.toJson(),
+        'custom_parent_class':
+            _serializeCustomParentClass(element.customParentClass),
         'fixed_entity_info_name': element.fixedEntityInfoName,
         'base_dart_name': element.baseDartName,
         'row_class_name': element.nameOfRowClass,
@@ -141,7 +142,8 @@ class ElementSerializer {
         'existing_data_class': element.existingRowClass != null
             ? _serializeExistingRowClass(element.existingRowClass!)
             : null,
-        'custom_parent_class': element.customParentClass?.toJson(),
+        'custom_parent_class':
+            _serializeCustomParentClass(element.customParentClass),
         'name_of_row_class': element.nameOfRowClass,
         'source': serializedSource,
       };
@@ -310,6 +312,15 @@ class ElementSerializer {
     };
   }
 
+  Map<String, Object?>? _serializeCustomParentClass(CustomParentClass? pc) {
+    if (pc == null) return null;
+
+    return {
+      'class': pc.parentClass.toJson(),
+      'const': pc.isConst,
+    };
+  }
+
   String? _serializeReferenceAction(ReferenceAction? action) {
     return action?.name;
   }
@@ -519,9 +530,8 @@ class ElementDeserializer {
             for (final constraint in json.list('table_constraints'))
               await _readTableConstraint(constraint as Map, columnByName),
           ],
-          customParentClass: json['custom_parent_class'] != null
-              ? AnnotatedDartCode.fromJson(json['custom_parent_class'] as Map)
-              : null,
+          customParentClass:
+              _readCustomParentClass(json['custom_parent_class'] as Map?),
           fixedEntityInfoName: json['fixed_entity_info_name'] as String?,
           baseDartName: json['base_dart_name'] as String,
           nameOfRowClass: json['row_class_name'] as String,
@@ -658,9 +668,8 @@ class ElementDeserializer {
           references: references,
           columns: columns,
           entityInfoName: json['entity_info_name'] as String,
-          customParentClass: json['custom_parent_class'] != null
-              ? AnnotatedDartCode.fromJson(json['custom_parent_class'] as Map)
-              : null,
+          customParentClass:
+              _readCustomParentClass(json['custom_parent_class'] as Map?),
           nameOfRowClass: json['name_of_row_class'] as String,
           existingRowClass: json['existing_data_class'] != null
               ? await _readExistingRowClass(
@@ -805,6 +814,15 @@ class ElementDeserializer {
     );
   }
 
+  CustomParentClass? _readCustomParentClass(Map? json) {
+    if (json == null) return null;
+
+    return CustomParentClass(
+      parentClass: AnnotatedDartCode.fromJson(json['class'] as Map),
+      isConst: json['const'] as bool,
+    );
+  }
+
   ReferenceAction? _readAction(String? value) {
     return value == null ? null : ReferenceAction.values.byName(value);
   }

drift_dev/lib/src/writer/tables/data_class_writer.dart

@@ -44,8 +44,9 @@ class DataClassWriter {
   }
 
   void write() {
-    final parentClass = table.customParentClass != null
-        ? _emitter.dartCode(table.customParentClass!)
+    final customParent = table.customParentClass;
+    final parentClass = customParent != null
+        ? _emitter.dartCode(customParent.parentClass)
         : _emitter.drift('DataClass');
     _buffer.write('class ${table.nameOfRowClass} extends $parentClass ');
 
@@ -76,8 +77,8 @@ class DataClassWriter {
     }
 
     // write constructor with named optional fields
-
-    if (!scope.options.generateMutableClasses) {
+    if (!scope.options.generateMutableClasses &&
+        customParent?.isConst != false) {
       _buffer.write('const ');
     }
     _emitter

drift_dev/test/analysis/resolver/dart/custom_row_classes_test.dart

@@ -440,7 +440,7 @@ class FooData {
       expect(file.allErrors, isEmpty);
 
       final table = file.analyzedElements.single as DriftTable;
-      expect(table.customParentClass?.toString(), 'BaseModel');
+      expect(table.customParentClass?.parentClass.toString(), 'BaseModel');
     });
 
     test('check valid with type argument', () async {
@@ -473,6 +473,14 @@ class FooData {
               '@DataClassName must be subtype of DataClass'))
         ],
       );
+
+      final table = file.analyzedElements.single as DriftTable;
+      expect(
+          table.customParentClass,
+          isA<CustomParentClass>()
+              .having((e) => e.isConst, 'isConst', false)
+              .having(
+                  (e) => e.parentClass.toString(), 'parentClass', 'BaseModel'));
     });
 
     test('wrong type argument in extending', () async {