fix for parser backtracking crash

evanw · evanw · commit ca196c9c4a27 · 2025-07-18T17:11:32.000-04:00
diff --git a/internal/js_parser/ts_parser.go b/internal/js_parser/ts_parser.go
@@ -981,6 +981,7 @@ func (originalParser *parser) isTypeScriptArrowReturnTypeAfterQuestionAndBeforeC
 		options: originalParser.options,
 		source:  originalParser.source,
 		lexer:   originalParser.lexer,
+		log:     logger.NewDeferLog(logger.DeferLogNoVerboseOrDebug, nil),
 		currentScope: &js_ast.Scope{
 			Kind:    js_ast.ScopeFunctionArgs,
 			Members: make(map[string]js_ast.ScopeMember),
diff --git a/internal/js_parser/ts_parser_test.go b/internal/js_parser/ts_parser_test.go
@@ -2388,6 +2388,7 @@ func TestTSArrow(t *testing.T) {
 	expectPrintedTS(t, "x = a ? (b) : T => c : d", "x = a ? (b) => c : d;\n")
 	expectPrintedTS(t, "x = a ? b - (c) : d => e", "x = a ? b - c : (d) => e;\n")
 	expectPrintedTS(t, "x = a ? b = (c) : T => d : e", "x = a ? b = (c) => d : e;\n")
+	expectPrintedTS(t, "x = (\n  a ? (b = c) : { d: e }\n)", "x = a ? b = c : { d: e };\n") // Note: Newlines are important (they trigger backtracking)
 	expectParseErrorTS(t, "x = a ? (b = c) : T => d : (e = f) : g", "<stdin>: ERROR: Expected \";\" but found \":\"\n")
 	expectParseErrorTS(t, "x = a ? b ? (c = d) : T => e : (f = g)", "<stdin>: ERROR: Expected \":\" but found end of file\n")
 	expectParseErrorTS(t, "x = a ? - (b) : c => d : e", "<stdin>: ERROR: Expected \";\" but found \":\"\n")
