fix(typescript): fix parsing of 'import("mod").C<<T>() => null>'

Split the '<<' token into two '<' tokens to match TypeScript's behavior.
quick-lint · Dec 13, 2023 · c609b39 · c609b39
1 parent 7776927
commit c609b39
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diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
@@ -46,6 +46,8 @@ Semantic Versioning.
     an arrow function parameter list.
   * Fixed a crash if certain diagnostics are reported after a TypeScript
     interface. (Implemented by [Rui Serra][].)
+  * `import("modulename").Class<<T>(params) => ReturnType>` in a type is now
+    parsed correctly.
 
 ## 2.18.0 (2023-11-03)
 

diff --git a/src/quick-lint-js/fe/parse-type.cpp b/src/quick-lint-js/fe/parse-type.cpp
@@ -678,7 +678,8 @@ void Parser::parse_and_visit_typescript_type_expression(
         break;
       }
     }
-    if (this->peek().type == Token_Type::less) {
+    if (this->peek().type == Token_Type::less ||
+        this->peek().type == Token_Type::less_less) {
       this->parse_and_visit_typescript_generic_arguments(v);
     }
     maybe_parse_dots_after_generic_arguments();

diff --git a/test/test-parse-typescript-type.cpp b/test/test-parse-typescript-type.cpp
@@ -2065,6 +2065,18 @@ TEST_F(Test_Parse_TypeScript_Type, imported_type) {
                           }));
   }
 
+  {
+    Spy_Visitor p = test_parse_and_visit_typescript_type_expression(
+        u8"import('mymod').MyClass<<T>() => ReturnType>"_sv, no_diags,
+        typescript_options);
+    EXPECT_THAT(p.visits, ElementsAreArray({
+                              "visit_enter_function_scope",  //
+                              "visit_variable_declaration",  // T
+                              "visit_variable_type_use",     // ReturnType
+                              "visit_exit_function_scope",   //
+                          }));
+  }
+
   test_parse_and_visit_typescript_type_expression(
       u8"import('mymod').MyClass<T>.prop"_sv,  //
       u8"                           ^^^^ Diag_Dot_Not_Allowed_After_Generic_Arguments_In_Type.property_name\n"_diag