Fix code generation for nullable arrays (#1237)

moor_generator/lib/src/model/column.dart

@@ -126,6 +126,9 @@ class MoorColumn implements HasDeclaration, HasType {
         ColumnType.real: 'GeneratedRealColumn',
       }[type];
 
+  @override
+  bool get isArray => false;
+
   MoorColumn({
     this.type,
     this.dartGetterName,

moor_generator/lib/src/model/sql_query.dart

@@ -358,6 +358,9 @@ class ResultColumn implements HasType {
   ResultColumn(this.name, this.type, this.nullable,
       {this.typeConverter, this.sqlParserColumn});
 
+  @override
+  bool get isArray => false;
+
   /// Hash-code that matching [compatibleTo], so that two compatible columns
   /// will have the same [compatibilityHashCode].
   int get compatibilityHashCode {
@@ -474,6 +477,7 @@ class FoundVariable extends FoundElement implements HasType {
   /// variables at runtime. We only accept queries where no explicitly numbered
   /// vars appear after an array. This means that we can expand array variables
   /// without having to look at other variables.
+  @override
   final bool isArray;
 
   final bool isRequired;
@@ -500,8 +504,7 @@ class FoundVariable extends FoundElement implements HasType {
 
   @override
   String dartTypeCode([GenerationOptions options = const GenerationOptions()]) {
-    final withoutArray = OperationOnTypes(this).dartTypeCode(options);
-    return isArray ? 'List<$withoutArray>' : withoutArray;
+    return OperationOnTypes(this).dartTypeCode(options);
   }
 }
 

moor_generator/lib/src/model/types.dart

@@ -10,6 +10,12 @@ abstract class HasType {
   /// Whether the type is nullable in Dart.
   bool get nullable;
 
+  /// Whether this type is an array in sql.
+  ///
+  /// In this case, [nullable] refers to the inner type as arrays are always
+  /// non-nullable.
+  bool get isArray;
+
   /// The associated sql type.
   ColumnType get type;
 
@@ -20,7 +26,7 @@ abstract class HasType {
 extension OperationOnTypes on HasType {
   /// Whether this type is nullable in Dart
   bool get nullableInDart {
-    return nullable || typeConverter?.hasNullableDartType == true;
+    return (nullable && !isArray) || typeConverter?.hasNullableDartType == true;
   }
 
   /// the Dart type of this column that can be handled by moors type mapping.
@@ -36,8 +42,14 @@ extension OperationOnTypes on HasType {
   /// This is the same as [dartTypeCode] but without custom types.
   String variableTypeCode(
       [GenerationOptions options = const GenerationOptions()]) {
-    final hasSuffix = nullableInDart && options.nnbd;
-    return hasSuffix ? '$variableTypeName?' : variableTypeName;
+    final innerHasSuffix = nullable && options.nnbd;
+    final result = innerHasSuffix ? '$variableTypeName?' : variableTypeName;
+
+    if (isArray) {
+      return 'List<$result>';
+    } else {
+      return result;
+    }
   }
 
   /// The dart type that matches the values of this column. For instance, if a

moor_generator/test/writer/queries/query_writer_test.dart

@@ -0,0 +1,32 @@
+// @dart=2.9
+import 'package:moor_generator/src/analyzer/options.dart';
+import 'package:moor_generator/src/analyzer/runner/results.dart';
+import 'package:moor_generator/writer.dart';
+import 'package:test/test.dart';
+
+import '../../analyzer/utils.dart';
+
+void main() {
+  test('generates correct parameter for nullable arrays', () async {
+    final state = TestState.withContent({
+      'a|lib/main.moor': '''
+        CREATE TABLE tbl (
+          id INTEGER NULL
+        );
+
+        query: SELECT * FROM tbl WHERE id IN :idList;
+      ''',
+    }, enableAnalyzer: false);
+    addTearDown(state.close);
+
+    final file = await state.analyze('package:a/main.moor');
+    final fileState = file.currentResult as ParsedMoorFile;
+
+    final writer = Writer(
+        const MoorOptions.defaults(generateNamedParameters: true),
+        generationOptions: const GenerationOptions(nnbd: true));
+    QueryWriter(fileState.resolvedQueries.single, writer.child()).write();
+
+    expect(writer.writeGenerated(), contains('required List<int?> idList'));
+  });
+}