From 1bbf3f582bfdf61cc5ea234bd82e2dbc9c739d58 Mon Sep 17 00:00:00 2001
From: Ariel Don <ariel@arieldon.com>
Date: Fri, 27 Oct 2023 12:42:50 -0500
Subject: [PATCH] fix(fe): don't report missing `else` for bad `if` expression

---
 src/quick-lint-js/fe/parse.h  |  2 +-
 test/test-parse-statement.cpp | 19 +++++++++++++++++++
 test/test-parse.cpp           |  5 +++--
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/src/quick-lint-js/fe/parse.h b/src/quick-lint-js/fe/parse.h
index 69d55e4f1c..09bd512b17 100644
--- a/src/quick-lint-js/fe/parse.h
+++ b/src/quick-lint-js/fe/parse.h
@@ -1172,7 +1172,7 @@ void Parser::parse_and_visit_parenthesized_expression(
 
   const Char8 *expression_begin = this->peek().begin;
 
-  Expression *ast = this->parse_expression(v);
+  Expression *ast = this->parse_expression(v, {.trailing_identifiers = true});
   this->visit_expression(ast, v, Variable_Context::rhs);
 
   if constexpr (check_for_sketchy_conditions) {
diff --git a/test/test-parse-statement.cpp b/test/test-parse-statement.cpp
index befaa08fce..894f7511cf 100644
--- a/test/test-parse-statement.cpp
+++ b/test/test-parse-statement.cpp
@@ -717,6 +717,25 @@ TEST_F(Test_Parse_Statement, else_without_if) {
                               "visit_exit_block_scope",
                           }));
   }
+
+  {
+    Test_Parser p(
+        u8"if (e isntanceof DataNotLoadedError) { } else { throw e; }"_sv,
+        capture_diags);
+    p.parse_and_visit_statement();
+    EXPECT_THAT(p.visits,
+                ElementsAreArray({"visit_variable_use",  // e
+                                  "visit_variable_use",  // typoed instanceof
+                                  "visit_variable_use",  // DataNotLoadedError
+                                  "visit_enter_block_scope",  //
+                                  "visit_exit_block_scope",   //
+                                  "visit_enter_block_scope",  //
+                                  "visit_variable_use",       // e
+                                  "visit_exit_block_scope"}));
+    EXPECT_THAT(
+        p.errors,
+        ::testing::Not(::testing::Contains(DIAG_TYPE(Diag_Else_Has_No_If))));
+  }
 }
 
 TEST_F(Test_Parse_Statement, missing_if_after_else) {
diff --git a/test/test-parse.cpp b/test/test-parse.cpp
index 474815828e..2f9dbff235 100644
--- a/test/test-parse.cpp
+++ b/test/test-parse.cpp
@@ -320,8 +320,9 @@ TEST_F(Test_Parse, utter_garbage) {
     assert_diagnostics(
         p.code, p.errors,
         {
-            u8"   ^ Diag_Expected_Parentheses_Around_If_Condition"_diag,  //
-            u8"   ^ Diag_Unexpected_Token"_diag,
+            u8"   ^ Diag_Unexpected_Token"_diag,  //
+            u8"      ^^^^^^^^ Diag_Unexpected_Identifier_In_Expression"_diag,  //
+            u8"   ^^^^^^^^^^^ Diag_Expected_Parentheses_Around_If_Condition"_diag,
         });
   }
 }