Generate code for Dart-defined index

drift/example/main.dart

@@ -12,6 +12,7 @@ class TodoCategories extends Table {
   TextColumn get name => text()();
 }
 
+@TableIndex(name: 'item_title', columns: {#title})
 class TodoItems extends Table {
   IntColumn get id => integer().autoIncrement()();
   TextColumn get title => text()();

drift/example/main.g.dart

@@ -689,10 +689,17 @@ abstract class _$Database extends GeneratedDatabase {
       $TodoCategoryItemCountView(this);
   late final $TodoItemWithCategoryNameViewView customViewName =
       $TodoItemWithCategoryNameViewView(this);
+  late final Index itemTitle =
+      Index('item_title', 'CREATE INDEX item_title ON todo_items (title)');
   @override
   Iterable<TableInfo<Table, Object?>> get allTables =>
       allSchemaEntities.whereType<TableInfo<Table, Object?>>();
   @override
-  List<DatabaseSchemaEntity> get allSchemaEntities =>
-      [todoCategories, todoItems, todoCategoryItemCount, customViewName];
+  List<DatabaseSchemaEntity> get allSchemaEntities => [
+        todoCategories,
+        todoItems,
+        todoCategoryItemCount,
+        customViewName,
+        itemTitle
+      ];
 }

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

@@ -65,6 +65,9 @@ class DartTableResolver extends LocalElementResolver<DiscoveredDartTable> {
       ],
       overrideTableConstraints: tableConstraints,
       withoutRowId: await _overrideWithoutRowId(element) ?? false,
+      attachedIndices: [
+        for (final id in discovered.attachedIndices) id.name,
+      ],
     );
 
     if (primaryKey != null &&

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

@@ -216,11 +216,14 @@ class _FindDartElements extends RecursiveElementVisitor<void> {
         _pendingWork.add(Future.sync(() async {
           final name = await _sqlNameOfTable(element);
           final id = _discoverStep._id(name);
-          found.add(DiscoveredDartTable(id, element));
+          final attachedIndices = <DriftElementId>[];
 
           for (final (annotation, indexId) in _tableIndexAnnotation(element)) {
+            attachedIndices.add(indexId);
             found.add(DiscoveredDartIndex(indexId, element, id, annotation));
           }
+
+          found.add(DiscoveredDartTable(id, element, attachedIndices));
         }));
       }
     } else if (_isDslView(element)) {

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

@@ -42,14 +42,34 @@ class FileAnalyzer {
             await driver.resolveElements(import.ownUri);
           }
 
+          final availableByDefault = <DriftSchemaElement>{
+            ...element.declaredTables,
+            ...element.declaredViews,
+          };
+
+          // For indices added to tables via an annotation, the index should
+          // also be available.
+          for (final table in element.declaredTables) {
+            final fileState = driver.cache.knownFiles[table.id.libraryUri]!;
+
+            for (final attachedIndex in table.attachedIndices) {
+              final index =
+                  fileState.analysis[fileState.id(attachedIndex)]?.result;
+              if (index is DriftIndex) {
+                availableByDefault.add(index);
+              }
+            }
+          }
+
           final availableElements = imported
               .expand((reachable) {
                 final elementAnalysis = reachable.analysis.values;
+
                 return elementAnalysis.map((e) => e.result).where(
                     (e) => e is DefinedSqlQuery || e is DriftSchemaElement);
               })
               .whereType<DriftElement>()
-              .followedBy(element.references)
+              .followedBy(availableByDefault)
               .transitiveClosureUnderReferences()
               .sortTopologicallyOrElse(driver.backend.log.severe);
 
@@ -58,15 +78,11 @@ class FileAnalyzer {
           // from a Dart file that hasn't been added to `tables`, emit a warning.
           // https://github.com/simolus3/drift/issues/2462#issuecomment-1620107751
           if (element is DriftDatabase) {
-            final explicitlyAdded = <DriftElementWithResultSet>{
-              ...element.declaredTables,
-              ...element.declaredViews,
-            };
             final implicitlyAdded = availableElements
                 .whereType<DriftElementWithResultSet>()
                 .where((element) =>
                     element.declaration.isDartDeclaration &&
-                    !explicitlyAdded.contains(element));
+                    !availableByDefault.contains(element));
 
             if (implicitlyAdded.isNotEmpty) {
               final names = implicitlyAdded
@@ -97,6 +113,9 @@ class FileAnalyzer {
 
           result.resolvedDatabases[element.id] =
               ResolvedDatabaseAccessor(queries, imports, availableElements);
+        } else if (element is DriftIndex) {
+          // We need the SQL AST for each index to create them in code
+          element.createStatementForDartDefinition();
         }
       }
     } else if (state.extension == '.drift' || state.extension == '.moor') {

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

@@ -38,7 +38,15 @@ class DiscoveredDartTable extends DiscoveredDartElement<ClassElement> {
   @override
   DriftElementKind get kind => DriftElementKind.table;
 
-  DiscoveredDartTable(super.ownId, super.dartElement);
+  /// The element ids of [DiscoveredDartIndex] entries that have been added to
+  /// this table with a `@TableIndex` annotation on the table class.
+  final List<DriftElementId> attachedIndices;
+
+  DiscoveredDartTable(
+    super.ownId,
+    super.dartElement,
+    this.attachedIndices,
+  );
 }
 
 class DiscoveredDartView extends DiscoveredDartElement<ClassElement> {

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

@@ -48,6 +48,27 @@ class DriftIndex extends DriftSchemaElement {
   /// This node is not serialized and only set in the late-state, local file
   /// analysis.
   CreateIndexStatement? parsedStatement;
+
+  /// At the moment, the index implementation in the generator writes the
+  /// `CREATE INDEX` definition as a string into the generated code. This
+  /// requires [parsedStatement] to be available when generating code. To ensure
+  /// this for Dart-based index declarations, this method creates a suitable AST
+  /// for a create index statement based on the information available in our
+  /// element model.
+  ///
+  /// Note that Dart index definitions are less expressive than the ones in SQL,
+  /// so this method should not be used for indices defined with SQL.
+  void createStatementForDartDefinition() {
+    parsedStatement = CreateIndexStatement(
+      indexName: id.name,
+      on: TableReference(table?.id.name ?? ''),
+      unique: unique,
+      columns: [
+        for (final column in indexedColumns)
+          IndexedColumn(Reference(columnName: column.nameInSql))
+      ],
+    );
+  }
 }
 
 sealed class DriftIndexDefintion {}

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

@@ -53,6 +53,14 @@ class DriftTable extends DriftElementWithResultSet {
   /// `customConstraints` getter in the table class with this value.
   final List<String> overrideTableConstraints;
 
+  /// The names of indices that have been attached to this table using the
+  /// `@TableIndex` annotation in drift.
+  ///
+  /// This field only has the purpose of implicitly adding these indices to each
+  /// database adding this table, so that code for that index will get generated
+  /// without an explicit reference.
+  final List<String> attachedIndices;
+
   DriftColumn? _rowIdColumn;
 
   DriftTable(
@@ -71,6 +79,7 @@ class DriftTable extends DriftElementWithResultSet {
     this.virtualTableData,
     this.writeDefaultConstraints = true,
     this.overrideTableConstraints = const [],
+    this.attachedIndices = const [],
   }) {
     _rowIdColumn = DriftColumn(
       sqlType: DriftSqlType.int,

drift_dev/lib/src/analysis/serializer.dart

@@ -62,6 +62,7 @@ class ElementSerializer {
           'virtual': _serializeVirtualTableData(element.virtualTableData!),
         'write_default_constraints': element.writeDefaultConstraints,
         'custom_constraints': element.overrideTableConstraints,
+        'attached_indices': element.attachedIndices,
       };
     } else if (element is DriftIndex) {
       additionalInformation = {
@@ -516,6 +517,7 @@ class ElementDeserializer {
           overrideTableConstraints: json['custom_constraints'] != null
               ? (json['custom_constraints'] as List).cast()
               : const [],
+          attachedIndices: (json['attached_indices'] as List).cast(),
         );
 
         for (final column in columns) {

drift_dev/lib/src/services/schema/schema_files.dart

@@ -311,6 +311,8 @@ class SchemaReader {
       if (sql != null) {
         index.parsedStatement =
             _engine.parse(sql).rootNode as CreateIndexStatement;
+      } else {
+        index.createStatementForDartDefinition();
       }
 
       return index;