Provide proper generation context during migrations

moor/lib/src/runtime/components/component.dart

@@ -18,7 +18,8 @@ class GenerationContext {
   /// queries.
   bool hasMultipleTables = false;
 
-  final QueryEngine database;
+  final SqlTypeSystem typeSystem;
+  final QueryExecutor executor;
 
   final List<dynamic> _boundVariables = [];
   List<dynamic> get boundVariables => _boundVariables;
@@ -29,7 +30,11 @@ class GenerationContext {
   /// Gets the generated sql statement
   String get sql => buffer.toString();
 
-  GenerationContext(this.database);
+  GenerationContext.fromDb(QueryEngine database)
+      : typeSystem = database.typeSystem,
+        executor = database.executor;
+
+  GenerationContext(this.typeSystem, this.executor);
 
   /// Introduces a variable that will be sent to the database engine. Whenever
   /// this method is called, a question mark should be added to the [buffer] so

moor/lib/src/runtime/database.dart

@@ -124,7 +124,7 @@ mixin QueryEngine on DatabaseConnectionUser {
   /// specified there will then issue another query.
   Future<int> customUpdate(String query,
       {List<Variable> variables = const [], Set<TableInfo> updates}) async {
-    final ctx = GenerationContext(this);
+    final ctx = GenerationContext.fromDb(this);
     final mappedArgs = variables.map((v) => v.mapToSimpleValue(ctx)).toList();
 
     final affectedRows =

moor/lib/src/runtime/expressions/variables.dart

@@ -40,7 +40,7 @@ class Variable<T, S extends SqlType<T>> extends Expression<T, S> {
   /// database engine. For instance, a [DateTime] will me mapped to its unix
   /// timestamp.
   dynamic mapToSimpleValue(GenerationContext context) {
-    final type = context.database.typeSystem.forDartType<T>();
+    final type = context.typeSystem.forDartType<T>();
     return type.mapToSqlVariable(value);
   }
 
@@ -69,7 +69,7 @@ class Constant<T, S extends SqlType<T>> extends Expression<T, S> {
 
   @override
   void writeInto(GenerationContext context) {
-    final type = context.database.typeSystem.forDartType<T>();
+    final type = context.typeSystem.forDartType<T>();
     context.buffer.write(type.mapToSqlConstant(value));
   }
 }

moor/lib/src/runtime/migration.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 
 import 'package:moor/moor.dart';
+import 'package:moor/src/runtime/components/component.dart';
 import 'package:moor/src/runtime/structure/columns.dart';
 import 'package:moor/src/runtime/structure/table_info.dart';
 
@@ -51,10 +52,15 @@ class Migrator {
     return Future.wait(_db.allTables.map(createTable));
   }
 
+  GenerationContext _createContext() {
+    return GenerationContext(
+        _db.typeSystem, _SimpleSqlAsQueryExecutor(_executor));
+  }
+
   /// Creates the given table if it doesn't exist
   Future<void> createTable(TableInfo table) async {
-    final sql = StringBuffer()
+    final context = _createContext();
-      ..write('CREATE TABLE IF NOT EXISTS ${table.$tableName} (');
+    context.buffer.write('CREATE TABLE IF NOT EXISTS ${table.$tableName} (');
 
     var hasAutoIncrement = false;
     for (var i = 0; i < table.$columns.length; i++) {
@@ -64,34 +70,34 @@ class Migrator {
         hasAutoIncrement = true;
       }
 
-      column.writeColumnDefinition(sql);
+      column.writeColumnDefinition(context);
 
-      if (i < table.$columns.length - 1) sql.write(', ');
+      if (i < table.$columns.length - 1) context.buffer.write(', ');
     }
 
     final hasPrimaryKey = table.$primaryKey?.isNotEmpty ?? false;
     if (hasPrimaryKey && !hasAutoIncrement) {
-      sql.write(', PRIMARY KEY (');
+      context.buffer.write(', PRIMARY KEY (');
       final pkList = table.$primaryKey.toList(growable: false);
       for (var i = 0; i < pkList.length; i++) {
         final column = pkList[i];
 
-        sql.write(column.$name);
+        context.buffer.write(column.$name);
 
-        if (i != pkList.length - 1) sql.write(', ');
+        if (i != pkList.length - 1) context.buffer.write(', ');
       }
-      sql.write(')');
+      context.buffer.write(')');
     }
 
     final constraints = table.asDslTable.customConstraints ?? [];
 
     for (var i = 0; i < constraints.length; i++) {
-      sql..write(', ')..write(constraints[i]);
+      context.buffer..write(', ')..write(constraints[i]);
     }
 
-    sql.write(');');
+    context.buffer.write(');');
 
-    return issueCustomQuery(sql.toString());
+    return issueCustomQuery(context.sql);
   }
 
   /// Deletes the table with the given name. Note that this function does not
@@ -102,14 +108,13 @@ class Migrator {
 
   /// Adds the given column to the specified table.
   Future<void> addColumn(TableInfo table, GeneratedColumn column) async {
-    final sql = StringBuffer();
+    final context = _createContext();
 
-    // ignore: cascade_invocations
+    context.buffer.write('ALTER TABLE ${table.$tableName} ADD COLUMN ');
-    sql.write('ALTER TABLE ${table.$tableName} ADD COLUMN ');
+    column.writeColumnDefinition(context);
-    column.writeColumnDefinition(sql);
+    context.buffer.write(';');
-    sql.write(';');
 
-    return issueCustomQuery(sql.toString());
+    return issueCustomQuery(context.sql);
   }
 
   /// Executes the custom query.
@@ -117,3 +122,49 @@ class Migrator {
     return _executor(sql);
   }
 }
+
+class _SimpleSqlAsQueryExecutor extends QueryExecutor {
+  final SqlExecutor executor;
+
+  _SimpleSqlAsQueryExecutor(this.executor);
+
+  @override
+  TransactionExecutor beginTransaction() {
+    throw UnsupportedError('Not supported for migrations');
+  }
+
+  @override
+  Future<bool> ensureOpen() {
+    return Future.value(true);
+  }
+
+  @override
+  Future<void> runBatched(List<BatchedStatement> statements) {
+    throw UnsupportedError('Not supported for migrations');
+  }
+
+  @override
+  Future<void> runCustom(String statement) {
+    return executor(statement);
+  }
+
+  @override
+  Future<int> runDelete(String statement, List args) {
+    throw UnsupportedError('Not supported for migrations');
+  }
+
+  @override
+  Future<int> runInsert(String statement, List args) {
+    throw UnsupportedError('Not supported for migrations');
+  }
+
+  @override
+  Future<List<Map<String, dynamic>>> runSelect(String statement, List args) {
+    throw UnsupportedError('Not supported for migrations');
+  }
+
+  @override
+  Future<int> runUpdate(String statement, List args) {
+    throw UnsupportedError('Not supported for migrations');
+  }
+}

moor/lib/src/runtime/statements/delete.dart

@@ -32,9 +32,8 @@ class DeleteStatement<T extends Table, D> extends Query<T, D>
   Future<int> go() async {
     final ctx = constructQuery();
 
-    return ctx.database.executor.doWhenOpened((e) async {
+    return ctx.executor.doWhenOpened((e) async {
-      final rows =
+      final rows = await ctx.executor.runDelete(ctx.sql, ctx.boundVariables);
-          await ctx.database.executor.runDelete(ctx.sql, ctx.boundVariables);
 
       if (rows > 0) {
         database.markTablesUpdated({table});

moor/lib/src/runtime/statements/insert.dart

@@ -86,7 +86,7 @@ class InsertStatement<DataClass> {
     final map = table.entityToSql(entry)
       ..removeWhere((_, value) => value == null);
 
-    final ctx = GenerationContext(database);
+    final ctx = GenerationContext.fromDb(database);
     ctx.buffer
       ..write('INSERT ')
       ..write(replace ? 'OR REPLACE ' : '')

moor/lib/src/runtime/statements/query.dart

@@ -35,7 +35,7 @@ abstract class Query<T extends Table, DataClass> {
   /// Constructs the query that can then be sent to the database executor.
   @protected
   GenerationContext constructQuery() {
-    final ctx = GenerationContext(database);
+    final ctx = GenerationContext.fromDb(database);
     var needsWhitespace = false;
 
     writeStartPart(ctx);

moor/lib/src/runtime/statements/select.dart

@@ -117,7 +117,7 @@ class JoinedSelectStatement<FirstT extends Table, FirstD>
   }
 
   Future<List<TypedResult>> _getWithQuery(GenerationContext ctx) async {
-    final results = await ctx.database.executor.doWhenOpened((e) async {
+    final results = await ctx.executor.doWhenOpened((e) async {
       return await e.runSelect(ctx.sql, ctx.boundVariables);
     });
 
@@ -162,7 +162,7 @@ class SimpleSelectStatement<T extends Table, D> extends Query<T, D>
   }
 
   Future<List<D>> _getWithQuery(GenerationContext ctx) async {
-    final results = await ctx.database.executor.doWhenOpened((e) async {
+    final results = await ctx.executor.doWhenOpened((e) async {
       return await e.runSelect(ctx.sql, ctx.boundVariables);
     });
     return results.map(table.map).toList();
@@ -263,7 +263,7 @@ class CustomSelectStatement {
   }
 
   List<dynamic> _mapArgs() {
-    final ctx = GenerationContext(_db);
+    final ctx = GenerationContext.fromDb(_db);
     return variables.map((v) => v.mapToSimpleValue(ctx)).toList();
   }
 

moor/lib/src/runtime/statements/update.dart

@@ -32,7 +32,7 @@ class UpdateStatement<T extends Table, D> extends Query<T, D>
 
   Future<int> _performQuery() async {
     final ctx = constructQuery();
-    final rows = await ctx.database.executor.doWhenOpened((e) async {
+    final rows = await ctx.executor.doWhenOpened((e) async {
       return await e.runUpdate(ctx.sql, ctx.boundVariables);
     });
 

moor/lib/src/runtime/structure/columns.dart

@@ -36,31 +36,28 @@ abstract class GeneratedColumn<T, S extends SqlType<T>> extends Column<T, S> {
   /// Writes the definition of this column, as defined
   /// [here](https://www.sqlite.org/syntax/column-def.html), into the given
   /// buffer.
-  void writeColumnDefinition(StringBuffer into) {
+  void writeColumnDefinition(GenerationContext into) {
-    into.write('$escapedName $typeName ');
+    into.buffer.write('$escapedName $typeName ');
 
     if ($customConstraints == null) {
-      into.write($nullable ? 'NULL' : 'NOT NULL');
+      into.buffer.write($nullable ? 'NULL' : 'NOT NULL');
 
       if (defaultValue != null) {
-        into.write(' DEFAULT ');
+        into.buffer.write(' DEFAULT ');
-
-        final fakeContext = GenerationContext(null);
-        defaultValue.writeInto(fakeContext);
 
         // we need to write brackets if the default value is not a literal.
         // see https://www.sqlite.org/syntax/column-constraint.html
         final writeBrackets = !defaultValue.isLiteral;
 
-        if (writeBrackets) into.write('(');
+        if (writeBrackets) into.buffer.write('(');
-        into.write(fakeContext.sql);
+        defaultValue.writeInto(into);
-        if (writeBrackets) into.write(')');
+        if (writeBrackets) into.buffer.write(')');
       }
 
       // these custom constraints refer to builtin constraints from moor
-      writeCustomConstraints(into);
+      writeCustomConstraints(into.buffer);
     } else {
-      into.write($customConstraints);
+      into.buffer.write($customConstraints);
     }
   }
 
@@ -164,9 +161,10 @@ class GeneratedIntColumn extends GeneratedColumn<int, IntType>
             $customConstraints: $customConstraints, defaultValue: defaultValue);
 
   @override
-  void writeColumnDefinition(StringBuffer into) {
+  void writeColumnDefinition(GenerationContext into) {
+    // todo make this work with custom constraints, default values, etc.
     if (hasAutoIncrement) {
-      into.write('${$name} $typeName PRIMARY KEY AUTOINCREMENT');
+      into.buffer.write('${$name} $typeName PRIMARY KEY AUTOINCREMENT');
     } else {
       super.writeColumnDefinition(into);
     }

moor/test/columns/datetime_test.dart

@@ -1,4 +1,5 @@
 import 'package:moor/moor.dart';
+import 'package:moor/src/runtime/components/component.dart';
 import 'package:test_api/test_api.dart';
 
 void main() {
@@ -6,12 +7,12 @@ void main() {
   final nonNull = GeneratedDateTimeColumn('name', null, false);
 
   test('should write column definition', () {
-    final nullableBuff = StringBuffer();
+    final nonNullQuery = GenerationContext(null, null);
-    final nonNullBuff = StringBuffer();
+    final nullableQuery = GenerationContext(null, null);
-    nullable.writeColumnDefinition(nullableBuff);
+    nonNull.writeColumnDefinition(nonNullQuery);
-    nonNull.writeColumnDefinition(nonNullBuff);
+    nullable.writeColumnDefinition(nullableQuery);
 
-    expect(nullableBuff.toString(), equals('name INTEGER NULL'));
+    expect(nullableQuery.sql, equals('name INTEGER NULL'));
-    expect(nonNullBuff.toString(), equals('name INTEGER NOT NULL'));
+    expect(nonNullQuery.sql, equals('name INTEGER NOT NULL'));
   });
 }

moor/test/expressions/comparable_test.dart

@@ -27,7 +27,7 @@ void main() {
 
     comparisons.forEach((fn, value) {
       test('for operator $value', () {
-        final ctx = GenerationContext(db);
+        final ctx = GenerationContext.fromDb(db);
 
         fn(compare).writeInto(ctx);
 
@@ -39,7 +39,7 @@ void main() {
   group('can compare with values', () {
     comparisonsVal.forEach((fn, value) {
       test('for operator $value', () {
-        final ctx = GenerationContext(db);
+        final ctx = GenerationContext.fromDb(db);
 
         fn(12).writeInto(ctx);
 

moor/test/expressions/datetime_expression_test.dart

@@ -20,7 +20,7 @@ void main() {
 
   expectedResults.forEach((key, value) {
     test('should extract field', () {
-      final ctx = GenerationContext(null);
+      final ctx = GenerationContext(const SqlTypeSystem.withDefaults(), null);
       key(column).writeInto(ctx);
 
       expect(ctx.sql, value);

moor/test/expressions/in_expression_test.dart

@@ -9,7 +9,7 @@ void main() {
     final innerExpression = moor.GeneratedTextColumn('name', null, true);
     final isInExpression = moor.isIn(innerExpression, ['Max', 'Tobias']);
 
-    final context = GenerationContext(TodoDb(null));
+    final context = GenerationContext.fromDb(TodoDb(null));
     isInExpression.writeInto(context);
 
     expect(context.sql, 'name IN (?, ?)');

moor/test/expressions/is_null_test.dart

@@ -10,7 +10,7 @@ void main() {
   test('IS NULL expressions are generated', () {
     final isNull = moor.isNull(innerExpression);
 
-    final context = GenerationContext(TodoDb(null));
+    final context = GenerationContext.fromDb(TodoDb(null));
     isNull.writeInto(context);
 
     expect(context.sql, 'name IS NULL');
@@ -19,7 +19,7 @@ void main() {
   test('IS NOT NULL expressions are generated', () {
     final isNotNull = moor.isNotNull(innerExpression);
 
-    final context = GenerationContext(TodoDb(null));
+    final context = GenerationContext.fromDb(TodoDb(null));
     isNotNull.writeInto(context);
 
     expect(context.sql, 'name IS NOT NULL');

moor/test/expressions/variable_test.dart

@@ -8,7 +8,7 @@ void main() {
   test('maps the variable to sql', () {
     final variable =
         Variable(DateTime.fromMillisecondsSinceEpoch(1551297563000));
-    final ctx = GenerationContext(TodoDb(null));
+    final ctx = GenerationContext.fromDb(TodoDb(null));
 
     variable.writeInto(ctx);
 
@@ -18,7 +18,7 @@ void main() {
 
   test('writes null directly for null values', () {
     final variable = Variable.withString(null);
-    final ctx = GenerationContext(TodoDb(null));
+    final ctx = GenerationContext.fromDb(TodoDb(null));
 
     variable.writeInto(ctx);
 

moor_flutter/pubspec.lock

@@ -7,7 +7,7 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
+    version: "2.1.0"
   boolean_selector:
     dependency: transitive
     description:
@@ -45,7 +45,7 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.3+1"
+    version: "0.12.5"
   meta:
     dependency: "direct main"
     description:
@@ -59,7 +59,7 @@ packages:
       path: "../moor"
       relative: true
     source: path
-    version: "1.3.0"
+    version: "1.3.1"
   path:
     dependency: "direct main"
     description:
@@ -73,14 +73,14 @@ packages:
       name: pedantic
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.4.0"
+    version: "1.5.0"
   quiver:
     dependency: transitive
     description:
       name: quiver
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.1"
+    version: "2.0.2"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -92,7 +92,7 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.5.4"
+    version: "1.5.5"
   sqflite:
     dependency: "direct main"
     description:
@@ -113,7 +113,7 @@ packages:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.8"
+    version: "2.0.0"
   string_scanner:
     dependency: transitive
     description:
@@ -141,7 +141,7 @@ packages:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.2"
+    version: "0.2.4"
   typed_data:
     dependency: transitive
     description:
@@ -157,4 +157,4 @@ packages:
     source: hosted
     version: "2.0.8"
 sdks:
-  dart: ">=2.1.0 <3.0.0"
+  dart: ">=2.2.0 <3.0.0"