fix(typescript): fix cyclic type definition check when using namespace

Author: strager

docs/CHANGELOG.md

@@ -51,6 +51,8 @@ Semantic Versioning.
   * Generic call signatures are now parsed correctly when using a semicolon-free
     coding style.
   * `declare const x = 42;` no longer falsely reports [E0351][] or [E0385][].
+  * `type T = T.thing;` no longer falsely reports [E0384][] ("cannot use type
+    directly in its own definition").
 
 ## 2.18.0 (2023-11-03)
 

src/quick-lint-js/fe/parse-type.cpp

@@ -277,7 +277,7 @@ void Parser::parse_and_visit_typescript_type_expression(
     }
 
     if (parse_options.type_being_declared.has_value() &&
-        this->peek().type != Token_Type::left_square) {
+        this->peek().type != Token_Type::left_square && !had_dot) {
       // Shallow use.
       if (name.normalized_name() ==
           parse_options.type_being_declared->name.normalized_name()) {

test/test-parse-typescript-generic.cpp

@@ -281,13 +281,6 @@ TEST_F(Test_Parse_TypeScript_Generic, extends_cannot_be_directly_cyclic) {
       u8"{.kind=Variable_Kind::_generic_parameter}"_diag,
       typescript_options);
 
-  test_parse_and_visit_typescript_generic_parameters(
-      u8"<T extends T.foo>"_sv,
-      u8"           ^ Diag_Cyclic_TypeScript_Type_Definition.use\n"_diag
-      u8" ^ .declaration"_diag
-      u8"{.kind=Variable_Kind::_generic_parameter}"_diag,
-      typescript_options);
-
   test_parse_and_visit_typescript_generic_parameters(
       u8"<T extends T<number>>"_sv,
       u8"           ^ Diag_Cyclic_TypeScript_Type_Definition.use\n"_diag
@@ -328,6 +321,16 @@ TEST_F(Test_Parse_TypeScript_Generic, extends_cannot_be_directly_cyclic) {
       typescript_options);
 }
 
+TEST_F(Test_Parse_TypeScript_Generic,
+       extends_can_reference_namespace_with_same_name_as_declared_variable) {
+  Spy_Visitor v = test_parse_and_visit_typescript_generic_parameters(
+      u8"<T extends T.foo>"_sv, no_diags, typescript_options);
+  EXPECT_THAT(v.visits, ElementsAreArray({
+                            "visit_variable_declaration",    // T
+                            "visit_variable_namespace_use",  // T (in T.foo)
+                        }));
+}
+
 TEST_F(Test_Parse_TypeScript_Generic, unexpected_colon_in_parameter_extends) {
   {
     Spy_Visitor p = test_parse_and_visit_typescript_generic_parameters(

test/test-parse-typescript-type-alias.cpp

@@ -190,13 +190,6 @@ TEST_F(Test_Parse_TypeScript_Type_Alias, type_alias_cannot_be_directly_cyclic) {
       u8"{.kind=Variable_Kind::_type_alias}"_diag,
       typescript_options);
 
-  test_parse_and_visit_statement(
-      u8"type T = T.foo;"_sv,
-      u8"         ^ Diag_Cyclic_TypeScript_Type_Definition.use\n"_diag
-      u8"     ^ .declaration"_diag
-      u8"{.kind=Variable_Kind::_type_alias}"_diag,
-      typescript_options);
-
   test_parse_and_visit_statement(
       u8"type T = T<number>;"_sv,
       u8"         ^ Diag_Cyclic_TypeScript_Type_Definition.use\n"_diag
@@ -243,6 +236,18 @@ TEST_F(Test_Parse_TypeScript_Type_Alias, type_alias_cannot_be_directly_cyclic) {
       typescript_options);
 }
 
+TEST_F(Test_Parse_TypeScript_Type_Alias,
+       type_alias_can_reference_namespace_with_same_name) {
+  Spy_Visitor v = test_parse_and_visit_statement(u8"type T = T.foo;"_sv,
+                                                 no_diags, typescript_options);
+  EXPECT_THAT(v.visits, ElementsAreArray({
+                            "visit_variable_declaration",    // T
+                            "visit_enter_type_alias_scope",  //
+                            "visit_variable_namespace_use",  // T (in T.foo)
+                            "visit_exit_type_alias_scope",   //
+                        }));
+}
+
 TEST_F(Test_Parse_TypeScript_Type_Alias,
        type_alias_can_be_named_certain_contextual_keywords) {
   for (String8 name :