Fix a crash if we had a dollar identifier as the second parameter lab…

…el in a closure not followed by a colon There was a mismatch between the call to `eat` and `at`. Switch the pair to a `consume(if:)` to avoid the issue. Fixes #3103

Sources/SwiftParser/Types.swift

@@ -944,13 +944,13 @@ extension Parser.Lookahead {
  // by a type annotation.
  if self.startsParameterName(isClosure: false, allowMisplacedSpecifierRecovery: false) {
  self.consumeAnyToken()
+ // If we have a secondary argument label, consume it.
  if self.atArgumentLabel() {
  self.consumeAnyToken()
- guard self.at(.colon) else {
- return false
- }
  }
- self.eat(.colon)
+ guard self.consume(if: .colon) != nil else {
+ return false
+ }
 
  // Parse a type.
  guard self.canParseType() else {

Tests/SwiftParserTest/ExpressionTests.swift

@@ -2145,6 +2145,26 @@ final class ExpressionTests: ParserTestCase {
  """
  )
  }
+
+ func testSecondaryArgumentLabelDollarIdentifierInClosure() {
+ assertParse(
+ """
+ ℹ️{ a1️⃣: (a $
+ """,
+ diagnostics: [
+ DiagnosticSpec(
+ message: "expected '}' to end closure",
+ notes: [NoteSpec(message: "to match this opening '{'")],
+ fixIts: ["insert '}'"]
+ ),
+ DiagnosticSpec(message: "extraneous code ': (a $' at top level"),
+ ],
+ fixedSource: """
+ { a
+ }: (a $
+ """
+ )
+ }
 }
 
 final class MemberExprTests: ParserTestCase {