orm: resolve generic inserting object type

Author: medvednikov

vlib/orm/orm_generic_struct_field_test.v

@@ -145,3 +145,33 @@ fn test_create_table_in_generic_function() {
 
 	queue.conn.close()!
 }
+
+// Test inserting from within a generic function
+// This tests the fix for the "cannot use `Message` as `Message[Payload]`" error
+pub fn (mut q Queue[T]) add_message(data string) !GenericMessage[T] {
+	msg := GenericMessage[T]{
+		data: data
+	}
+	sql q.conn {
+		insert msg into GenericMessage[T]
+	}!
+	return msg
+}
+
+fn test_insert_in_generic_function() {
+	mut queue := create_queue[Payload](':memory:')!
+
+	// Insert from within a generic function
+	msg := queue.add_message('inserted from generic fn')!
+	assert msg.data == 'inserted from generic fn'
+
+	// Verify it was inserted
+	messages := sql queue.conn {
+		select from GenericMessage[Payload]
+	}!
+
+	assert messages.len == 1
+	assert messages[0].data == 'inserted from generic fn'
+
+	queue.conn.close()!
+}

vlib/v/checker/orm.v

@@ -277,6 +277,13 @@ fn (mut c Checker) sql_stmt_line(mut node ast.SqlStmtLine) ast.Type {
 			inserting_object_type = inserting_object.typ.deref()
 		}
 
+		// Resolve generic inserting object type if we're inside a generic function context
+		if inserting_object_type.has_flag(.generic) && c.table.cur_fn != unsafe { nil }
+			&& c.table.cur_fn.generic_names.len > 0 && c.table.cur_concrete_types.len > 0 {
+			inserting_object_type = c.table.unwrap_generic_type(inserting_object_type,
+				c.table.cur_fn.generic_names, c.table.cur_concrete_types)
+		}
+
 		if inserting_object_type != node.table_expr.typ
 			&& !c.table.sumtype_has_variant(inserting_object_type, node.table_expr.typ, false) {
 			table_name := table_sym.name