Merge pull request #1492 from westito/generate_tocompanion

Add 'toCompanion' generator for custom row classes

drift/lib/src/dsl/table.dart

@@ -155,9 +155,17 @@ class UseRowClass {
   /// used to map database rows to the desired row class.
   final String constructor;
 
+  /// Generate a `toInsertable()` extension function for [type] mapping all
+  /// fields to an insertable object.
+  ///
+  /// This can be useful when a custom data class should be used for inserts or
+  /// updates.
+  final bool generateInsertable;
+
   /// Customize the class used by drift to hold an instance of an annotated
   /// table.
   ///
   /// For details, see the overall documentation on [UseRowClass].
-  const UseRowClass(this.type, {this.constructor = ''});
+  const UseRowClass(this.type,
+      {this.constructor = '', this.generateInsertable = false});
 }

drift/test/data/tables/todos.dart

@@ -58,7 +58,7 @@ class SharedTodos extends Table {
 
 const _uuid = Uuid();
 
-@UseRowClass(CustomRowClass, constructor: 'map')
+@UseRowClass(CustomRowClass, constructor: 'map', generateInsertable: true)
 class TableWithoutPK extends Table {
   IntColumn get notReallyAnId => integer()();
   RealColumn get someFloat => real()();
@@ -67,13 +67,15 @@ class TableWithoutPK extends Table {
       text().map(const CustomConverter()).clientDefault(_uuid.v4)();
 }
 
-class CustomRowClass implements Insertable<CustomRowClass> {
+class CustomRowClass {
   final int notReallyAnId;
   final double anotherName;
   final MyCustomObject custom;
 
   final String? notFromDb;
 
+  double get someFloat => anotherName;
+
   CustomRowClass._(
       this.notReallyAnId, this.anotherName, this.custom, this.notFromDb);
 
@@ -81,15 +83,6 @@ class CustomRowClass implements Insertable<CustomRowClass> {
       {required MyCustomObject custom, String? notFromDb}) {
     return CustomRowClass._(notReallyAnId, someFloat, custom, notFromDb);
   }
-
-  @override
-  Map<String, Expression> toColumns(bool nullToAbsent) {
-    return TableWithoutPKCompanion(
-      notReallyAnId: Value(notReallyAnId),
-      someFloat: Value(anotherName),
-      custom: Value(custom),
-    ).toColumns(nullToAbsent);
-  }
 }
 
 class PureDefaults extends Table {

drift/test/data/tables/todos.g.dart

@@ -1054,6 +1054,27 @@ class TableWithoutPKCompanion extends UpdateCompanion<CustomRowClass> {
   }
 }
 
+class _$CustomRowClassInsertable implements Insertable<CustomRowClass> {
+  CustomRowClass _object;
+
+  _$CustomRowClassInsertable(this._object);
+
+  @override
+  Map<String, Expression> toColumns(bool nullToAbsent) {
+    return TableWithoutPKCompanion(
+      notReallyAnId: Value(_object.notReallyAnId),
+      someFloat: Value(_object.someFloat),
+      custom: Value(_object.custom),
+    ).toColumns(false);
+  }
+}
+
+extension CustomRowClassToInsertable on CustomRowClass {
+  _$CustomRowClassInsertable toInsertable() {
+    return _$CustomRowClassInsertable(this);
+  }
+}
+
 class $TableWithoutPKTable extends TableWithoutPK
     with TableInfo<$TableWithoutPKTable, CustomRowClass> {
   final GeneratedDatabase _db;

drift/test/insert_test.dart

@@ -31,7 +31,8 @@ void main() {
   test('can insert floating point values', () async {
     // regression test for https://github.com/simolus3/moor/issues/30
     await db.into(db.tableWithoutPK).insert(
-        CustomRowClass.map(42, 3.1415, custom: MyCustomObject('custom')));
+        CustomRowClass.map(42, 3.1415, custom: MyCustomObject('custom'))
+            .toInsertable());
 
     verify(executor.runInsert(
         'INSERT INTO table_without_p_k '

drift_dev/lib/src/analyzer/custom_row_class.dart

@@ -15,8 +15,12 @@ class FoundDartClass {
   FoundDartClass(this.classElement, this.instantiation);
 }
 
-ExistingRowClass? validateExistingClass(Iterable<MoorColumn> columns,
+ExistingRowClass? validateExistingClass(
-    FoundDartClass dartClass, String constructor, ErrorSink errors) {
+    Iterable<MoorColumn> columns,
+    FoundDartClass dartClass,
+    String constructor,
+    bool generateInsertable,
+    ErrorSink errors) {
   final desiredClass = dartClass.classElement;
   ConstructorElement? ctor;
 
@@ -52,8 +56,22 @@ ExistingRowClass? validateExistingClass(Iterable<MoorColumn> columns,
   for (final parameter in ctor.parameters) {
     final column = unmatchedColumnsByName.remove(parameter.name);
     if (column != null) {
-      columnsToParameter[column] = parameter;
+      final matchField = !generateInsertable ||
-      _checkType(parameter, column, errors);
+          dartClass.classElement.fields
+              .any((field) => field.name == parameter.name);
+      if (matchField) {
+        columnsToParameter[column] = parameter;
+        _checkType(parameter, column, errors);
+      } else {
+        final error = ErrorInDartCode(
+            affectedElement: parameter,
+            severity: Severity.criticalError,
+            message: 'Constructor parameter ${parameter.name} has no matching '
+                'field. When "generateInsertable" enabled, all constructor '
+                'parameter must have a matching field. Alternatively, you can '
+                'declare a getter field.');
+        throw Exception(error);
+      }
     } else if (!parameter.isOptional) {
       errors.report(ErrorInDartCode(
         affectedElement: parameter,
@@ -63,7 +81,8 @@ ExistingRowClass? validateExistingClass(Iterable<MoorColumn> columns,
     }
   }
 
-  return ExistingRowClass(desiredClass, ctor, columnsToParameter,
+  return ExistingRowClass(
+      desiredClass, ctor, columnsToParameter, generateInsertable,
       typeInstantiation: dartClass.instantiation ?? const []);
 }
 

drift_dev/lib/src/analyzer/dart/table_parser.dart

@@ -70,6 +70,7 @@ class TableParser {
     String name;
     FoundDartClass? existingClass;
     String? constructorInExistingClass;
+    bool? generateInsertable;
 
     if (dataClassName != null) {
       name = dataClassName.getField('name')!.toStringValue()!;
@@ -81,6 +82,8 @@ class TableParser {
       final type = useRowClass.getField('type')!.toTypeValue();
       constructorInExistingClass =
           useRowClass.getField('constructor')!.toStringValue()!;
+      generateInsertable =
+          useRowClass.getField('generateInsertable')!.toBoolValue()!;
 
       if (type is InterfaceType) {
         existingClass = FoundDartClass(type.element, type.typeArguments);
@@ -96,7 +99,7 @@ class TableParser {
     final verified = existingClass == null
         ? null
         : validateExistingClass(columns, existingClass,
-            constructorInExistingClass!, base.step.errors);
+            constructorInExistingClass!, generateInsertable!, base.step.errors);
     return _DataClassInformation(name, verified);
   }
 

drift_dev/lib/src/analyzer/moor/create_table_reader.dart

@@ -181,7 +181,7 @@ class CreateTableReader {
           ));
         } else {
           existingRowClass = validateExistingClass(
-              foundColumns.values, clazz, '', step.errors);
+              foundColumns.values, clazz, '', false, step.errors);
           dataClassName = existingRowClass?.targetClass.name;
         }
       } else if (overriddenNames.contains('/')) {

drift_dev/lib/src/analyzer/view/view_analyzer.dart

@@ -64,7 +64,7 @@ class ViewAnalyzer extends BaseAnalyzer {
             ));
           } else {
             final rowClass = view.existingRowClass =
-                validateExistingClass(columns, clazz, '', step.errors);
+                validateExistingClass(columns, clazz, '', false, step.errors);
             final newName = rowClass?.targetClass.name;
             if (newName != null) {
               view.dartTypeName = rowClass!.targetClass.name;

drift_dev/lib/src/model/base_entity.dart

@@ -69,7 +69,11 @@ class ExistingRowClass {
   final ConstructorElement constructor;
   final Map<MoorColumn, ParameterElement> mapping;
 
-  ExistingRowClass(this.targetClass, this.constructor, this.mapping,
+  /// Generate toCompanion for data class
+  final bool generateInsertable;
+
+  ExistingRowClass(
+      this.targetClass, this.constructor, this.mapping, this.generateInsertable,
       {this.typeInstantiation = const []});
 
   String dartType([GenerationOptions options = const GenerationOptions()]) {

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

@@ -1,3 +1,4 @@
+import 'package:collection/collection.dart';
 import 'package:drift_dev/moor_generator.dart';
 import 'package:drift_dev/src/utils/string_escaper.dart';
 import 'package:drift_dev/src/writer/utils/override_toString.dart';
@@ -28,6 +29,10 @@ class UpdateCompanionWriter {
     _writeToString();
 
     _buffer.write('}\n');
+
+    if (table.existingRowClass?.generateInsertable ?? false) {
+      _writeToCompanionExtension();
+    }
   }
 
   void _writeFields() {
@@ -211,4 +216,39 @@ class UpdateCompanionWriter {
       _buffer,
     );
   }
+
+  void _writeToCompanionExtension() {
+    final info = table.existingRowClass;
+    if (info == null) return;
+
+    final companionName = table.getNameForCompanionClass(scope.options);
+    final className = table.dartTypeName;
+    final insertableClass = '_\$${className}Insertable';
+
+    _buffer.write('class $insertableClass implements '
+        'Insertable<$className> {\n'
+        '$className _object;\n\n'
+        '$insertableClass(this._object);\n\n'
+        '@override\n'
+        'Map<String, Expression> toColumns(bool nullToAbsent) {\n'
+        'return $companionName(\n');
+
+    for (final field in info.mapping.values) {
+      final column =
+          table.columns.firstWhereOrNull((e) => e.dartGetterName == field.name);
+
+      if (column != null) {
+        final dartName = column.dartGetterName;
+        _buffer.write('$dartName: Value (_object.$dartName),\n');
+      }
+    }
+
+    _buffer
+      ..write(').toColumns(false);\n}\n}\n\n')
+      ..write('extension ${table.dartTypeName}ToInsertable '
+          'on ${table.dartTypeName} {')
+      ..write('$insertableClass toInsertable() {\n')
+      ..write('return _\$${className}Insertable(this);\n')
+      ..write('}\n}\n');
+  }
 }