checker: handle unknown fields in fail_if_immutable

vlib/gx/gx.v

@@ -49,6 +49,7 @@ pub const (
 
 pub const (
 	align_left  = 1
+	align_right = 4
 	ALIGN_RIGHT = 4
 )
 

vlib/net/http/http.v

@@ -44,6 +44,14 @@ pub:
 	status_code int
 }
 
+pub fn new_request(method, url, data string) ?Request{
+	return Request{
+		method: method
+		url: url
+		data: data
+	}
+}
+
 pub fn get(url string) ?Response {
 	return fetch_with_method('GET', url, FetchConfig{})
 }

vlib/v/checker/checker.v

@@ -523,7 +523,11 @@ fn (mut c Checker) fail_if_immutable(expr ast.Expr) {
 			match typ_sym.kind {
 				.struct_ {
 					struct_info := typ_sym.info as table.Struct
-					field_info := struct_info.get_field(it.field_name)
+					field_info := struct_info.find_field(it.field_name) or {
+						type_str := c.table.type_to_str(it.expr_type)
+						c.error('unknown field `${type_str}.$it.field_name`', it.pos)
+						return
+					}
 					if !field_info.is_mut {
 						type_str := c.table.type_to_str(it.expr_type)
 						c.error('field `$it.field_name` of struct `${type_str}` is immutable', it.pos)