Fix embedding Dart expressions without type

Author: simolus3

drift_dev/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.22.1-dev
+
+- Fix generating Dart expressions without an inferred type.
+
 ## 2.22.0
 
 - CLI options dealing with schemas now support views defined in Dart ([#3285](https://github.com/simolus3/drift/issues/3285)).

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

@@ -23,11 +23,13 @@ extension FoundElementType on FoundElement {
               break;
           }
         } else if (kind is ExpressionDartPlaceholderType) {
-          builder
-            ..addSymbol('Expression', AnnotatedDartCode.drift)
-            ..addText('<')
-            ..addCode(scope.innerColumnType(kind.columnType!))
-            ..addText('>');
+          builder.addSymbol('Expression', AnnotatedDartCode.drift);
+          if (kind.columnType case final type?) {
+            builder
+              ..addText('<')
+              ..addCode(scope.innerColumnType(type))
+              ..addText('>');
+          }
         } else if (kind is InsertableDartPlaceholderType) {
           final table = kind.table;
 

drift_dev/test/writer/queries/query_writer_test.dart

@@ -547,4 +547,31 @@ query (:foo AS TEXT): SELECT :foo;
       ),
     );
   });
+
+  test('can use placeholders without specific type', () async {
+    final result = await generateForQueryInDriftFile(
+      r'''
+CREATE TABLE examples (
+  description TEXT NOT NULL
+);
+
+query: SELECT CAST ($status AS INT) AS status FROM examples;
+''',
+      options: const DriftOptions.defaults(
+        dialect: DialectOptions(null, [SqlDialect.sqlite], null),
+      ),
+    );
+
+    expect(
+      result,
+      allOf(
+        contains(
+          r'''return customSelect('SELECT CAST(${generatedstatus.sql} AS INT) AS status''',
+        ),
+        contains(
+          r'typedef Query$status = Expression Function(Examples examples);',
+        ),
+      ),
+    );
+  });
 }