x.json2.decoder2: support nesteded maps (#23027)

Author: enghitalo

vlib/x/json2/decoder2/decode.v

@@ -322,7 +322,7 @@ fn (mut checker Decoder) check_json_format(val string) ! {
 					}
 				}
 			}
-			if checker.checker_idx < checker_end - 1 {
+			if checker.checker_idx < checker_end - 2 {
 				checker.checker_idx++
 			}
 		}
@@ -748,9 +748,12 @@ fn (mut decoder Decoder) decode_map[K, V](mut val map[K]V) ! {
 
 			mut map_value := V{}
 
-			decoder.decode_value(mut map_value)!
-
-			val[key] = map_value
+			$if V is $map {
+				val[key] = map_value.move()
+			} $else {
+				val[key] = map_value
+			}
+			decoder.decode_value(mut val[key])!
 		}
 	}
 }

vlib/x/json2/decoder2/tests/decode_object_test.v

@@ -39,14 +39,16 @@ fn test_array_of_strings() {
 	assert json.decode[map[string]string]('{"val": "2"}')! == {
 		'val': '2'
 	}
-	// assert json.decode[map[string]int]('{"val": 2}')! == {"val": 2}
+	assert json.decode[map[string]int]('{"val": 2}')! == {
+		'val': 2
+	}
 
-	// // nested map
-	// assert json.decode[map[string]map[string]string]('{"val": {"val2": "2"}}')! == {
-	// 	'val': {
-	// 		'val2': '2'
-	// 	}
-	// }
+	// nested map
+	assert json.decode[map[string]map[string]string]('{"val": {"val2": "2"}}')! == {
+		'val': {
+			'val2': '2'
+		}
+	}
 
 	// nested struct
 	assert json.decode[Stru]('{"val": 1, "val2": "lala", "val3": {"a": 2, "brazilian_steak": "leleu"}}')! == Stru{