fix: allow this in type queries

Author: amaanq

common/define-grammar.js

@@ -819,6 +819,7 @@ module.exports = function defineGrammar(dialect) {
  _type_query_member_expression: $ => seq(
  field('object', choice(
  $.identifier,
+ $.this,
  alias($._type_query_subscript_expression, $.subscript_expression),
  alias($._type_query_member_expression, $.member_expression),
  alias($._type_query_call_expression, $.call_expression),
@@ -832,6 +833,7 @@ module.exports = function defineGrammar(dialect) {
  _type_query_subscript_expression: $ => seq(
  field('object', choice(
  $.identifier,
+ $.this,
  alias($._type_query_subscript_expression, $.subscript_expression),
  alias($._type_query_member_expression, $.member_expression),
  alias($._type_query_call_expression, $.call_expression),
@@ -865,6 +867,7 @@ module.exports = function defineGrammar(dialect) {
  alias($._type_query_call_expression, $.call_expression),
  alias($._type_query_instantiation_expression, $.instantiation_expression),
  $.identifier,
+ $.this,
  ),
  )),
 

test/corpus/types.txt

@@ -2100,7 +2100,7 @@ type X2 = (typeof Y)[keyof typeof Z];
  (identifier))))))
 
 =========================
-Type of instantiation expressions
+Typeof instantiation expressions
 =========================
 
 // This is a special construct, different from both "typeof (f<T>)" and
@@ -2119,3 +2119,51 @@ type T = typeof f<T>;
  (identifier)
  (type_arguments
  (type_identifier))))))
+
+=========================
+Typeof this
+=========================
+
+class A {
+ colors: [ { color: "green", code: "#E5F8F2" } ]
+ color: (typeof this.colors)[number] = this.colors[0]
+}
+
+---
+
+(program
+ (class_declaration
+ (type_identifier)
+ (class_body
+ (public_field_definition
+ (property_identifier)
+ (type_annotation
+ (tuple_type
+ (object_type
+ (property_signature
+ (property_identifier)
+ (type_annotation
+ (literal_type
+ (string
+ (string_fragment)))))
+ (property_signature
+ (property_identifier)
+ (type_annotation
+ (literal_type
+ (string
+ (string_fragment)))))))))
+ (public_field_definition
+ (property_identifier)
+ (type_annotation
+ (lookup_type
+ (parenthesized_type
+ (type_query
+ (member_expression
+ (this)
+ (property_identifier))))
+ (predefined_type)))
+ (subscript_expression
+ (member_expression
+ (this)
+ (property_identifier))
+ (number))))))