Fix crash, support type converters in views

docs/pages/docs/Using SQL/drift_files.md

@@ -349,6 +349,7 @@ Future<List<Route>> routesByStart(int startPointId) {
 You can import and use [type converters]({{ "../Advanced Features/type_converters.md" | pageUrl }})
 written in Dart in a drift file. Importing a Dart file works with a regular `import` statement.
 To apply a type converter on a column definition, you can use the `MAPPED BY` column constraints:
+
 ```sql
 CREATE TABLE users (
   id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
@@ -357,6 +358,18 @@ CREATE TABLE users (
 );
 ```
 
+Queries or views that reference a table-column with a type converter will also inherit that
+converter. In addition, both queries and views can specify a type converter to use for a
+specific column as well:
+
+```sql
+CREATE VIEW my_view AS SELECT 'foo' MAPPED BY `const PreferenceConverter()`
+
+SELECT
+  id,
+  json_extract(preferences, '$.settings') MAPPED BY `const PreferenceConverter()`
+FROM users;
+```
 
 More details on type converts in drift files are available
 [here]({{ "../Advanced Features/type_converters.md#using-converters-in-moor" | pageUrl }}).
@@ -365,17 +378,6 @@ When using type converters, we recommend the [`apply_converters_on_variables`]({
 build option. This will also apply the converter from Dart to SQL, for instance if used on variables: `SELECT * FROM users WHERE preferences = ?`.
 With that option, the variable will be inferred to `Preferences` instead of `String`.
 
-The `MAPPED BY` syntax can also used on individual columns in a query:
-
-```sql
-SELECT
-  id,
-  json_extract(preferences, '$.settings') MAPPED BY `const PreferenceConverter`
-FROM users;
-```
-
-Type converters applied to columns in a select query will be used to map that column
-from SQL to Dart when the query is executed.
 
 ### Existing row classes
 

drift_dev/CHANGELOG.md

@@ -1,7 +1,7 @@
 
 ## 2.5.0-dev
 
-- Support `MAPPED BY` for individual columns in a select statement
+- Support `MAPPED BY` for individual columns in queries or in views defined with SQL.
 
 ## 2.4.1
 

drift_dev/lib/src/analysis/resolver/drift/element_resolver.dart

@@ -1,7 +1,9 @@
+import 'package:analyzer/dart/ast/ast.dart' as dart;
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:collection/collection.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
+import 'package:drift/drift.dart';
 import 'package:sqlparser/sqlparser.dart';
 import 'package:sqlparser/utils/find_referenced_tables.dart';
 
@@ -18,6 +20,35 @@ abstract class DriftElementResolver<T extends DiscoveredElement>
   DriftElementResolver(
       super.file, super.discovered, super.resolver, super.state);
 
+  Future<AppliedTypeConverter?> typeConverterFromMappedBy(
+      DriftSqlType sqlType, bool nullable, MappedBy mapper) async {
+    final code = mapper.mapper.dartCode;
+
+    dart.Expression expression;
+    try {
+      expression = await resolver.driver.backend.resolveExpression(
+        file.ownUri,
+        code,
+        file.discovery!.importDependencies
+            .map((e) => e.toString())
+            .where((e) => e.endsWith('.dart')),
+      );
+    } on CannotReadExpressionException catch (e) {
+      reportError(DriftAnalysisError.inDriftFile(mapper, e.msg));
+      return null;
+    }
+
+    final knownTypes = await resolver.driver.loadKnownTypes();
+    return readTypeConverter(
+      knownTypes.helperLibrary,
+      expression,
+      sqlType,
+      nullable,
+      (msg) => reportError(DriftAnalysisError.inDriftFile(mapper, msg)),
+      knownTypes,
+    );
+  }
+
   void reportLints(AnalysisContext context, Iterable<DriftElement> references) {
     context.errors.forEach(reportLint);
 

drift_dev/lib/src/analysis/resolver/drift/table.dart

@@ -1,4 +1,3 @@
-import 'package:analyzer/dart/ast/ast.dart' as dart;
 import 'package:collection/collection.dart';
 import 'package:drift/drift.dart' show DriftSqlType;
 import 'package:drift_dev/src/analysis/driver/driver.dart';
@@ -8,7 +7,6 @@ import 'package:sqlparser/sqlparser.dart' as sql;
 import 'package:sqlparser/utils/node_to_text.dart';
 
 import '../../../utils/string_escaper.dart';
-import '../../backend.dart';
 import '../../driver/error.dart';
 import '../../driver/state.dart';
 import '../../results/results.dart';
@@ -97,7 +95,8 @@ class DriftTableResolver extends DriftElementResolver<DiscoveredDriftTable> {
             continue;
           }
 
-          converter = await _readTypeConverter(type, nullable, constraint);
+          converter =
+              await typeConverterFromMappedBy(type, nullable, constraint);
         } else if (constraint is sql.JsonKey) {
           writeIntoTable = false;
           overriddenJsonName = constraint.jsonKey;
@@ -343,33 +342,4 @@ class DriftTableResolver extends DriftElementResolver<DiscoveredDriftTable> {
 
     return driftTable;
   }
-
-  Future<AppliedTypeConverter?> _readTypeConverter(
-      DriftSqlType sqlType, bool nullable, MappedBy mapper) async {
-    final code = mapper.mapper.dartCode;
-
-    dart.Expression expression;
-    try {
-      expression = await resolver.driver.backend.resolveExpression(
-        file.ownUri,
-        code,
-        file.discovery!.importDependencies
-            .map((e) => e.toString())
-            .where((e) => e.endsWith('.dart')),
-      );
-    } on CannotReadExpressionException catch (e) {
-      reportError(DriftAnalysisError.inDriftFile(mapper, e.msg));
-      return null;
-    }
-
-    final knownTypes = await resolver.driver.loadKnownTypes();
-    return readTypeConverter(
-      knownTypes.helperLibrary,
-      expression,
-      sqlType,
-      nullable,
-      (msg) => reportError(DriftAnalysisError.inDriftFile(mapper, msg)),
-      knownTypes,
-    );
-  }
 }

drift_dev/lib/src/analysis/resolver/drift/view.dart

@@ -1,7 +1,8 @@
 import 'package:recase/recase.dart';
 import 'package:sqlparser/sqlparser.dart';
-import 'package:sqlparser/utils/node_to_text.dart';
+import 'package:sqlparser/sqlparser.dart' as sql;
 
+import '../../../writer/queries/sql_writer.dart';
 import '../../driver/state.dart';
 import '../../results/results.dart';
 import '../intermediate_state.dart';
@@ -27,26 +28,48 @@ class DriftViewResolver extends DriftElementResolver<DiscoveredDriftView> {
 
     final columns = <DriftColumn>[];
     final columnDartNames = <String>{};
+
     for (final column in parserView.resolvedColumns) {
       final type = column.type;
+      final driftType = resolver.driver.typeMapping.sqlTypeToDrift(type);
+      final nullable = type?.nullable ?? true;
+
       AppliedTypeConverter? converter;
+      var ownsConverter = false;
+
+      // If this column has a `MAPPED BY` constraint, we can apply the converter
+      // through that.
+      final source = column.source;
+      if (source is ExpressionColumn) {
+        final mappedBy = source.mappedBy;
+        if (mappedBy != null) {
+          converter =
+              await typeConverterFromMappedBy(driftType, nullable, mappedBy);
+          ownsConverter = true;
+        }
+      }
+
       if (type != null && type.hint is TypeConverterHint) {
-        converter = (type.hint as TypeConverterHint).converter;
+        converter ??= (type.hint as TypeConverterHint).converter;
       }
 
       final driftColumn = DriftColumn(
-        sqlType: resolver.driver.typeMapping.sqlTypeToDrift(type),
+        sqlType: driftType,
         nameInSql: column.name,
         nameInDart:
             dartNameForSqlColumn(column.name, existingNames: columnDartNames),
         declaration: DriftDeclaration.driftFile(stmt, file.ownUri),
-        nullable: type?.nullable == true,
+        nullable: nullable,
         typeConverter: converter,
         foreignConverter: true,
       );
 
       columns.add(driftColumn);
       columnDartNames.add(driftColumn.nameInDart);
+
+      if (ownsConverter) {
+        converter?.owningColumn = driftColumn;
+      }
     }
 
     var entityInfoName = ReCase(stmt.viewName).pascalCase;
@@ -74,7 +97,7 @@ class DriftViewResolver extends DriftElementResolver<DiscoveredDriftView> {
       query: stmt.query,
       // Remove drift-specific syntax
       driftTableName: null,
-    ).toSql();
+    ).toSqlWithoutDriftSpecificSyntax(resolver.driver.options);
 
     return DriftView(
       discovered.ownId,

drift_dev/lib/src/analysis/resolver/queries/query_analyzer.dart

@@ -149,9 +149,10 @@ class QueryAnalyzer {
         final expression = await driver.backend.resolveExpression(
           fromFile.ownUri,
           mappedBy.mapper.dartCode,
-          fromFile.discovery!.importDependencies
-              .map((e) => e.toString())
-              .where((e) => e.endsWith('.dart')),
+          fromFile.discovery?.importDependencies
+                  .map((e) => e.toString())
+                  .where((e) => e.endsWith('.dart')) ??
+              const Iterable.empty(),
         );
 
         _resolvedExpressions[mappedBy.mapper] = expression;

drift_dev/lib/src/writer/queries/sql_writer.dart

@@ -24,6 +24,13 @@ String placeholderContextName(FoundDartPlaceholder placeholder) {
   return 'generated${placeholder.name}';
 }
 
+extension ToSqlText on AstNode {
+  String toSqlWithoutDriftSpecificSyntax(DriftOptions options) {
+    final writer = SqlWriter(options);
+    return writer.writeSql(this);
+  }
+}
+
 class SqlWriter extends NodeSqlBuilder {
   final StringBuffer _out;
   final SqlQuery? query;

drift_dev/test/analysis/resolver/drift/create_view_test.dart

@@ -145,4 +145,79 @@ CREATE VIEW IF NOT EXISTS repro AS
       'fooBarBaz', // fooBarBaz
     ]);
   });
+
+  test('copies type converter from table', () async {
+    final backend = TestBackend.inTest({
+      'a|lib/a.drift': '''
+import 'converter.dart';
+
+CREATE TABLE users (
+  id INTEGER NOT NULL PRIMARY KEY,
+  foo INTEGER NOT NULL MAPPED BY `createConverter()`
+);
+
+CREATE VIEW foos AS SELECT foo FROM users;
+''',
+      'a|lib/converter.dart': '''
+import 'package:drift/drift.dart';
+
+TypeConverter<Object, int> createConverter() => throw UnimplementedError();
+''',
+    });
+
+    final state = await backend.analyze('package:a/a.drift');
+    backend.expectNoErrors();
+
+    final table = state.analysis[state.id('users')]!.result as DriftTable;
+    final tableColumn = table.columnBySqlName['foo'];
+
+    final view = state.analysis[state.id('foos')]!.result as DriftView;
+    final column = view.columns.single;
+
+    expect(
+      column.typeConverter,
+      isA<AppliedTypeConverter>()
+          .having(
+              (e) => e.expression.toString(), 'expression', 'createConverter()')
+          .having((e) => e.owningColumn, 'owningColumn', tableColumn),
+    );
+  });
+
+  test('can declare type converter on view column', () async {
+    final backend = TestBackend.inTest({
+      'a|lib/a.drift': '''
+import 'converter.dart';
+
+CREATE VIEW v AS SELECT 1 MAPPED BY `createConverter()` AS r;
+''',
+      'a|lib/converter.dart': '''
+import 'package:drift/drift.dart';
+
+TypeConverter<Object, int> createConverter() => throw UnimplementedError();
+''',
+    });
+
+    final state = await backend.analyze('package:a/a.drift');
+    backend.expectNoErrors();
+
+    final view = state.analyzedElements.single as DriftView;
+    final column = view.columns.single;
+
+    expect(
+      column.typeConverter,
+      isA<AppliedTypeConverter>()
+          .having(
+              (e) => e.expression.toString(), 'expression', 'createConverter()')
+          .having((e) => e.owningColumn, 'owningColumn', column),
+    );
+
+    expect(
+      view.source,
+      isA<SqlViewSource>().having(
+        (e) => e.sqlCreateViewStmt,
+        'sqlCreateViewStmt',
+        'CREATE VIEW v AS SELECT 1 AS r;',
+      ),
+    );
+  });
 }

drift_dev/test/analysis/test_utils.dart

@@ -4,7 +4,7 @@ import 'dart:isolate';
 import 'package:analyzer/dart/analysis/analysis_context.dart';
 import 'package:analyzer/dart/analysis/analysis_context_collection.dart';
 import 'package:analyzer/dart/analysis/results.dart';
-import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/dart/ast/ast.dart' as dart;
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/file_system/overlay_file_system.dart';
 import 'package:analyzer/file_system/physical_file_system.dart';
@@ -34,6 +34,7 @@ class TestBackend extends DriftBackend {
   late final DriftAnalysisDriver driver;
 
   AnalysisContext? _dartContext;
+  OverlayResourceProvider? _resourceProvider;
 
   TestBackend(
     Map<String, String> sourceContents, {
@@ -72,8 +73,21 @@ class TestBackend extends DriftBackend {
     }
   }
 
+  String _pathFor(Uri uri) {
+    if (uri.scheme == 'package') {
+      final package = uri.pathSegments.first;
+      final path =
+          p.url.joinAll(['/$package/lib', ...uri.pathSegments.skip(1)]);
+
+      return path;
+    }
+
+    return uri.path;
+  }
+
   Future<void> _setupDartAnalyzer() async {
-    final provider = OverlayResourceProvider(PhysicalResourceProvider.INSTANCE);
+    final provider = _resourceProvider =
+        OverlayResourceProvider(PhysicalResourceProvider.INSTANCE);
 
     // Analyze example sources against the drift sources from the current
     // drift_dev test runner.
@@ -93,15 +107,8 @@ class TestBackend extends DriftBackend {
 
     // Also put sources into the overlay:
     sourceContents.forEach((key, value) {
-      final uri = Uri.parse(key);
-
-      if (uri.scheme == 'package') {
-        final package = uri.pathSegments.first;
-        final path =
-            p.url.joinAll(['/$package/lib', ...uri.pathSegments.skip(1)]);
-
-        provider.setOverlay(path, content: value, modificationStamp: 1);
-      }
+      final path = _pathFor(Uri.parse(key));
+      provider.setOverlay(path, content: value, modificationStamp: 1);
     });
 
     if (analyzerExperiments.isNotEmpty) {
@@ -142,9 +149,38 @@ class TestBackend extends DriftBackend {
   }
 
   @override
-  Future<Never> resolveExpression(
+  Future<dart.Expression> resolveExpression(
       Uri context, String dartExpression, Iterable<String> imports) async {
-    throw UnsupportedError('Not currently supported in tests');
+    final fileContents = StringBuffer();
+    for (final import in imports) {
+      fileContents.writeln("import '$import';");
+    }
+    fileContents.writeln('var field = $dartExpression;');
+    final path = '${_pathFor(context)}.exp.dart';
+
+    await _setupDartAnalyzer();
+    final resourceProvider = _resourceProvider!;
+    final analysisContext = _dartContext!;
+
+    resourceProvider.setOverlay(path,
+        content: fileContents.toString(), modificationStamp: 1);
+
+    try {
+      final result =
+          await analysisContext.currentSession.getResolvedLibrary(path);
+
+      if (result is ResolvedLibraryResult) {
+        final unit = result.units.single.unit;
+        final field =
+            unit.declarations.single as dart.TopLevelVariableDeclaration;
+
+        return field.variables.variables.single.initializer!;
+      } else {
+        throw CannotReadExpressionException('Could not resolve temp file');
+      }
+    } finally {
+      resourceProvider.removeOverlay(path);
+    }
   }
 
   @override
@@ -157,7 +193,7 @@ class TestBackend extends DriftBackend {
   }
 
   @override
-  Future<AstNode?> loadElementDeclaration(Element element) async {
+  Future<dart.AstNode?> loadElementDeclaration(Element element) async {
     final library = element.library;
     if (library == null) return null;
 

sqlparser/lib/src/analysis/schema/column.dart

@@ -198,7 +198,15 @@ class ExpressionColumn extends Column {
   /// The expression returned by this column.
   final Expression expression;
 
-  ExpressionColumn({required this.name, required this.expression});
+  /// When drift extensions are enabled and this column was defined with a
+  /// `MAPPED BY` clause, a reference to that clause.
+  final MappedBy? mappedBy;
+
+  ExpressionColumn({
+    required this.name,
+    required this.expression,
+    this.mappedBy,
+  });
 }
 
 /// A column that is created by a reference expression. The difference to an
@@ -219,7 +227,8 @@ class ReferenceExpressionColumn extends ExpressionColumn {
 
   final String? overriddenName;
 
-  ReferenceExpressionColumn(Reference ref, {this.overriddenName})
+  ReferenceExpressionColumn(Reference ref,
+      {this.overriddenName, super.mappedBy})
       : super(name: '_', expression: ref);
 }
 

sqlparser/lib/src/analysis/steps/column_resolver.dart

@@ -293,12 +293,18 @@ class ColumnResolver extends RecursiveVisitor<void, void> {
         Column column;
 
         if (expression is Reference) {
-          column = ReferenceExpressionColumn(expression,
-              overriddenName: resultColumn.as);
+          column = ReferenceExpressionColumn(
+            expression,
+            overriddenName: resultColumn.as,
+            mappedBy: resultColumn.mappedBy,
+          );
         } else {
           final name = _nameOfResultColumn(resultColumn)!;
-          column =
-              ExpressionColumn(name: name, expression: resultColumn.expression);
+          column = ExpressionColumn(
+            name: name,
+            expression: resultColumn.expression,
+            mappedBy: resultColumn.mappedBy,
+          );
         }
 
         usedColumns.add(column);