Ensure Parameters property of arrow function is never nil

ahejlsberg · ahejlsberg · commit 769c99a6bee6 · 2025-10-03T08:50:33.000-07:00
diff --git a/internal/parser/parser.go b/internal/parser/parser.go
@@ -4198,6 +4198,7 @@ func (p *Parser) parseParenthesizedArrowFunctionExpression(allowAmbiguity bool,
 		if !allowAmbiguity {
 			return nil
 		}
+		parameters = p.parseEmptyNodeList()
 	} else {
 		if !allowAmbiguity {
 			maybeParameters := p.parseParametersWorker(signatureFlags, allowAmbiguity)

Original file line number	Diff line number	Diff line change
`@@ -4198,6 +4198,7 @@ func (p *Parser) parseParenthesizedArrowFunctionExpression(allowAmbiguity bool,`
`4198`	`4198`	`if !allowAmbiguity {`
`4199`	`4199`	`return nil`
`4200`	`4200`	`}`
	`4201`	`+ parameters = p.parseEmptyNodeList()`
`4201`	`4202`	`} else {`
`4202`	`4203`	`if !allowAmbiguity {`
`4203`	`4204`	`maybeParameters := p.parseParametersWorker(signatureFlags, allowAmbiguity)`