Add delete methods code generation and fix update methods

example/lib/database.dart

@@ -88,6 +88,9 @@ abstract class MyDatabase extends FloorDatabase {
 
   @update
   Future<void> updatePerson(Person person);
+
+  @delete
+  Future<void> deletePerson(Person person);
 }
 
 Future<void> main() async {

floor/lib/src/annotations.dart

@@ -62,3 +62,11 @@ class Update {
 
 /// Marks a method as an update method.
 const update = Update();
+
+/// Marks a method as a delete method.
+class Delete {
+  const Delete();
+}
+
+/// Marks a method as a delete method.
+const delete = Delete();

floor_generator/lib/misc/constants.dart

@@ -14,6 +14,7 @@ abstract class Annotation {
   static const QUERY = 'Query';
   static const INSERT = 'Insert';
   static const UPDATE = 'Update';
+  static const DELETE = 'Delete';
 }
 
 abstract class AnnotationField {

floor_generator/lib/misc/type_utils.dart

@@ -60,6 +60,10 @@ bool isUpdateAnnotation(ElementAnnotation annotation) {
   return _getAnnotationName(annotation) == Annotation.UPDATE;
 }
 
+bool isDeleteAnnotation(ElementAnnotation annotation) {
+  return _getAnnotationName(annotation) == Annotation.DELETE;
+}
+
 DartType flattenList(DartType type) {
   return (type as ParameterizedType).typeArguments.first;
 }

floor_generator/lib/model/database.dart

@@ -1,5 +1,6 @@
 import 'package:analyzer/dart/element/element.dart';
 import 'package:floor_generator/misc/type_utils.dart';
+import 'package:floor_generator/model/delete_method.dart';
 import 'package:floor_generator/model/entity.dart';
 import 'package:floor_generator/model/insert_method.dart';
 import 'package:floor_generator/model/query_method.dart';
@@ -36,6 +37,13 @@ class Database {
         .toList();
   }
 
+  List<DeleteMethod> get deleteMethods {
+    return methods
+        .where((method) => method.metadata.any(isDeleteAnnotation))
+        .map((method) => DeleteMethod(method))
+        .toList();
+  }
+
   List<Entity> getEntities(LibraryReader library) {
     return library.classes
         .where((clazz) =>

floor_generator/lib/model/delete_method.dart

@@ -0,0 +1,51 @@
+import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/dart/element/type.dart';
+import 'package:floor_generator/misc/type_utils.dart';
+import 'package:floor_generator/model/entity.dart';
+import 'package:source_gen/source_gen.dart';
+
+class DeleteMethod {
+  final MethodElement method;
+
+  DeleteMethod(this.method);
+
+  DartType get returnType => method.returnType;
+
+  String get name => method.displayName;
+
+  ParameterElement get parameter {
+    final parameters = method.parameters;
+    if (parameters.isEmpty) {
+      throw InvalidGenerationSourceError(
+        'There is no parameter supplied for an update method. Please add one.',
+        element: method,
+      );
+    } else if (parameters.length > 1) {
+      throw InvalidGenerationSourceError(
+        'Only one parameter is allowed on update methods.',
+        element: method,
+      );
+    }
+    return parameters.first;
+  }
+
+  Entity getEntity(LibraryReader library) {
+    final entityClass = _getEntities(library).firstWhere(
+        (entity) => entity.displayName == parameter.type.displayName);
+
+    return Entity(entityClass);
+  }
+
+  bool insertsEntity(LibraryReader library) {
+    return _getEntities(library)
+        .map((clazz) => clazz.displayName)
+        .any((entity) => entity == parameter.type.displayName);
+  }
+
+  List<ClassElement> _getEntities(LibraryReader library) {
+    return library.classes
+        .where((clazz) =>
+            !clazz.isAbstract && clazz.metadata.any(isEntityAnnotation))
+        .toList();
+  }
+}

floor_generator/lib/writer/database_writer.dart

@@ -1,10 +1,12 @@
 import 'package:floor_generator/misc/annotation_expression.dart';
 import 'package:floor_generator/misc/type_utils.dart';
 import 'package:floor_generator/model/database.dart';
+import 'package:floor_generator/model/delete_method.dart';
 import 'package:floor_generator/model/entity.dart';
 import 'package:floor_generator/model/insert_method.dart';
 import 'package:floor_generator/model/query_method.dart';
 import 'package:floor_generator/model/update_method.dart';
+import 'package:floor_generator/writer/delete_method_writer.dart';
 import 'package:floor_generator/writer/insert_method_writer.dart';
 import 'package:floor_generator/writer/query_method_writer.dart';
 import 'package:floor_generator/writer/update_method_writer.dart';
@@ -82,14 +84,8 @@ class DatabaseWriter implements Writer {
       ..methods.add(_generateOpenMethod(databaseName, createTableStatements))
       ..methods.addAll(_generateQueryMethods(database.queryMethods))
       ..methods.addAll(_generateInsertMethods(database.insertMethods))
-      ..methods.addAll(_generateUpdateMethods(database.updateMethods)));
-  }
-
-  List<Method> _generateUpdateMethods(List<UpdateMethod> updateMethods) {
-    return updateMethods
-        .map(
-            (updateMethod) => UpdateMethodWriter(library, updateMethod).write())
-        .toList();
+      ..methods.addAll(_generateUpdateMethods(database.updateMethods))
+      ..methods.addAll(_generateDeleteMethods(database.deleteMethods)));
   }
 
   Method _generateOpenMethod(
@@ -116,14 +112,25 @@ class DatabaseWriter implements Writer {
 
   List<Method> _generateInsertMethods(List<InsertMethod> insertMethods) {
     return insertMethods
-        .map(
-            (insertMethod) => InsertMethodWriter(library, insertMethod).write())
+        .map((method) => InsertMethodWriter(library, method).write())
         .toList();
   }
 
   List<Method> _generateQueryMethods(List<QueryMethod> queryMethods) {
     return queryMethods
-        .map((queryMethod) => QueryMethodWriter(library, queryMethod).write())
+        .map((method) => QueryMethodWriter(library, method).write())
+        .toList();
+  }
+
+  List<Method> _generateUpdateMethods(List<UpdateMethod> updateMethods) {
+    return updateMethods
+        .map((method) => UpdateMethodWriter(library, method).write())
+        .toList();
+  }
+
+  List<Method> _generateDeleteMethods(List<DeleteMethod> deleteMethods) {
+    return deleteMethods
+        .map((method) => DeleteMethodWriter(library, method).write())
         .toList();
   }
 

floor_generator/lib/writer/delete_method_writer.dart

@@ -0,0 +1,48 @@
+import 'package:code_builder/code_builder.dart';
+import 'package:floor_generator/misc/annotation_expression.dart';
+import 'package:floor_generator/model/delete_method.dart';
+import 'package:floor_generator/writer/writer.dart';
+import 'package:source_gen/source_gen.dart';
+
+class DeleteMethodWriter implements Writer {
+  final LibraryReader library;
+  final DeleteMethod deleteMethod;
+
+  DeleteMethodWriter(this.library, this.deleteMethod);
+
+  @override
+  Method write() {
+    return _generateDeleteMethod();
+  }
+
+  Method _generateDeleteMethod() {
+    // TODO assert deletes entity
+
+    return Method((builder) => builder
+      ..annotations.add(overrideAnnotationExpression)
+      ..returns = refer(deleteMethod.returnType.displayName)
+      ..name = deleteMethod.name
+      ..requiredParameters.add(_generateParameter())
+      ..modifier = MethodModifier.async
+      ..body = Code(_generateMethodBody()));
+  }
+
+  Parameter _generateParameter() {
+    final parameter = deleteMethod.parameter;
+
+    return Parameter((builder) => builder
+      ..name = parameter.name
+      ..type = refer(parameter.type.displayName));
+  }
+
+  String _generateMethodBody() {
+    final entity = deleteMethod.getEntity(library);
+    final primaryKeyColumn =
+        entity.columns.firstWhere((column) => column.isPrimaryKey);
+    final methodHeadParameterName = deleteMethod.parameter.name;
+
+    return '''
+    await this.database.rawDelete('DELETE FROM ${entity.name} WHERE ${primaryKeyColumn.name} = \${$methodHeadParameterName.${primaryKeyColumn.field.displayName}}');
+    ''';
+  }
+}

floor_generator/lib/writer/update_method_writer.dart

@@ -1,5 +1,7 @@
+import 'package:analyzer/dart/element/element.dart';
 import 'package:code_builder/code_builder.dart';
 import 'package:floor_generator/misc/annotation_expression.dart';
+import 'package:floor_generator/misc/type_utils.dart';
 import 'package:floor_generator/model/update_method.dart';
 import 'package:floor_generator/writer/writer.dart';
 import 'package:source_gen/source_gen.dart';
@@ -36,13 +38,40 @@ class UpdateMethodWriter implements Writer {
   }
 
   String _generateMethodBody() {
+    final parameter = updateMethod.parameter;
+    final methodHeadParameterName = parameter.displayName;
+
+    final keyValueList = (parameter.type.element as ClassElement)
+        .constructors
+        .first
+        .parameters
+        .map((parameter) {
+      final valueMapping = _getValueMapping(parameter, methodHeadParameterName);
+
+      return "'${parameter.displayName}': $valueMapping";
+    }).join(', ');
+
     final entity = updateMethod.getEntity(library);
-    final primaryKeyColumn =
-        entity.columns.firstWhere((column) => column.isPrimaryKey);
-    final methodHeadParameterName = updateMethod.parameter.name;
 
+    // TODO exclude id?
     return '''
-    await this.database.rawDelete('DELETE FROM ${entity.name} WHERE ${primaryKeyColumn.name} = \${$methodHeadParameterName.${primaryKeyColumn.field.displayName}}');
+    final values = <String, dynamic>{
+      $keyValueList
+    };
+    await this.database.update('${entity.name}', values);
     ''';
   }
+
+  String _getValueMapping(
+    ParameterElement parameter,
+    String methodParameterName,
+  ) {
+    final parameterName = parameter.displayName;
+
+    if (isBool(parameter.type)) {
+      return '$methodParameterName.$parameterName ? 1 : 0';
+    } else {
+      return '$methodParameterName.$parameterName';
+    }
+  }
 }