fix(lex): parse let f = (): RT<T>=>null;

Test Plan: `let f = (): RT<T>=>null;` Fixes #1169
quick-lint · Jan 8, 2024 · 1e8190c · 1e8190c
1 parent b05e1cc
commit 1e8190c
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diff --git a/src/quick-lint-js/fe/lex.cpp b/src/quick-lint-js/fe/lex.cpp
@@ -996,7 +996,12 @@ void Lexer::skip_less_less_as_less() {
 void Lexer::skip_as_greater() {
   switch (this->last_token_.type) {
   case Token_Type::greater_equal:
-    this->last_token_.type = Token_Type::equal;
+    if (this->input_[0] == '>') {
+      this->last_token_.type = Token_Type::equal_greater;
+      this->input_ += 1;
+    } else {
+      this->last_token_.type = Token_Type::equal;
+    }
     break;
   case Token_Type::greater_greater_equal:
     this->last_token_.type = Token_Type::greater_equal;

diff --git a/test/test-parse-typescript-generic-arrow.cpp b/test/test-parse-typescript-generic-arrow.cpp
@@ -26,6 +26,7 @@ namespace quick_lint_js {
 namespace {
 class Test_Parse_TypeScript_Generic_Arrow : public Test_Parse_Expression {};
 
+
 TEST_F(Test_Parse_TypeScript_Generic_Arrow, generic_arrow_function) {
   {
     Spy_Visitor p = test_parse_and_visit_statement(

diff --git a/test/test-parse-typescript-generic.cpp b/test/test-parse-typescript-generic.cpp
@@ -1098,6 +1098,75 @@ TEST_F(
   }
 }
 
+TEST_F(Test_Parse_TypeScript_Generic,
+       greater_equal_greater_is_split_into_two_tokens) {
+  {
+    Spy_Visitor p = test_parse_and_visit_statement(
+        u8"let f = (): RT<T> => null;"_sv, no_diags, typescript_options);
+    EXPECT_THAT(p.visits, ElementsAreArray({
+                              "visit_enter_function_scope",       //
+                              "visit_enter_type_scope",           // :
+                              "visit_variable_type_use",          // RT
+                              "visit_variable_type_use",          // T
+                              "visit_exit_type_scope",            //
+                              "visit_enter_function_scope_body",  // {
+                              "visit_exit_function_scope",        // }
+                              "visit_variable_declaration",       // let f
+                          }));
+    EXPECT_THAT(p.variable_declarations,
+                ElementsAreArray({let_init_decl(u8"f")}));
+  }
+  {
+    Spy_Visitor p = test_parse_and_visit_statement(
+        u8"let f = (): RT<T>=>null;"_sv, no_diags, typescript_options);
+    EXPECT_THAT(p.visits, ElementsAreArray({
+                              "visit_enter_function_scope",       //
+                              "visit_enter_type_scope",           // :
+                              "visit_variable_type_use",          // RT
+                              "visit_variable_type_use",          // T
+                              "visit_exit_type_scope",            //
+                              "visit_enter_function_scope_body",  // {
+                              "visit_exit_function_scope",        // }
+                              "visit_variable_declaration",       // let f
+                          }));
+    EXPECT_THAT(p.variable_declarations,
+                ElementsAreArray({let_init_decl(u8"f")}));
+  }
+  {
+    Spy_Visitor p = test_parse_and_visit_statement(
+        u8"let f = (): RT<T>=> null;"_sv, no_diags, typescript_options);
+    EXPECT_THAT(p.visits, ElementsAreArray({
+                              "visit_enter_function_scope",       //
+                              "visit_enter_type_scope",           // :
+                              "visit_variable_type_use",          // RT
+                              "visit_variable_type_use",          // T
+                              "visit_exit_type_scope",            //
+                              "visit_enter_function_scope_body",  // {
+                              "visit_exit_function_scope",        // }
+                              "visit_variable_declaration",       // let f
+                          }));
+    EXPECT_THAT(p.variable_declarations,
+                ElementsAreArray({let_init_decl(u8"f")}));
+  }
+  {
+    Spy_Visitor p = test_parse_and_visit_statement(
+        u8"let f = (): RT<RT<T>>=> null;"_sv, no_diags, typescript_options);
+    EXPECT_THAT(p.visits, ElementsAreArray({
+                              "visit_enter_function_scope",       //
+                              "visit_enter_type_scope",           // :
+                              "visit_variable_type_use",          // RT
+                              "visit_variable_type_use",          // RT
+                              "visit_variable_type_use",          // T
+                              "visit_exit_type_scope",            //
+                              "visit_enter_function_scope_body",  // {
+                              "visit_exit_function_scope",        // }
+                              "visit_variable_declaration",       // let f
+                          }));
+    EXPECT_THAT(p.variable_declarations,
+                ElementsAreArray({let_init_decl(u8"f")}));
+  }
+}
+
 TEST_F(Test_Parse_TypeScript_Generic,
        unambiguous_generic_arguments_are_parsed_in_javascript) {
   {