From d27e1e3cb36003ec8adb472e02290c28ba0d0fbf Mon Sep 17 00:00:00 2001
From: Cal Stephens <cal@calstephens.tech>
Date: Sat, 20 Sep 2025 10:08:40 -0700
Subject: [PATCH] Fix support for trailing commas in tuples in generic
 arguments

---
 Sources/SwiftParser/Types.swift             |  3 +-
 Tests/SwiftParserTest/ExpressionTests.swift | 47 +++++++++++++++++++++
 2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/Sources/SwiftParser/Types.swift b/Sources/SwiftParser/Types.swift
index 94fa029b0f5..91441f903c5 100644
--- a/Sources/SwiftParser/Types.swift
+++ b/Sources/SwiftParser/Types.swift
@@ -1025,7 +1025,8 @@ extension Parser.Lookahead {
       }
 
       self.consumeIfContextualPunctuator("...")
-    } while self.consume(if: .comma) != nil && self.hasProgressed(&loopProgress)
+
+    } while self.consume(if: .comma) != nil && !self.at(.rightParen) && self.hasProgressed(&loopProgress)
     return self.consume(if: .rightParen) != nil
   }
 
diff --git a/Tests/SwiftParserTest/ExpressionTests.swift b/Tests/SwiftParserTest/ExpressionTests.swift
index 791620ad652..9533e6b4f56 100644
--- a/Tests/SwiftParserTest/ExpressionTests.swift
+++ b/Tests/SwiftParserTest/ExpressionTests.swift
@@ -2225,6 +2225,53 @@ final class ExpressionTests: ParserTestCase {
       let _ = ((Int, Bool, String,) -> Void).self
       """
     )
+
+    assertParse(
+      """
+      let _ = Array<(
+        bar: String,
+        baaz: String,
+      )>()
+      """,
+      substructure: FunctionCallExprSyntax(
+        calledExpression: GenericSpecializationExprSyntax(
+          expression: DeclReferenceExprSyntax(baseName: .identifier("Array")),
+          genericArgumentClause: GenericArgumentClauseSyntax(
+            leftAngle: .leftAngleToken(),
+            arguments: GenericArgumentListSyntax([
+              GenericArgumentSyntax(
+                argument: .type(
+                  TypeSyntax(
+                    TupleTypeSyntax(
+                      leftParen: .leftParenToken(),
+                      elements: TupleTypeElementListSyntax([
+                        TupleTypeElementSyntax(
+                          firstName: .identifier("bar"),
+                          colon: .colonToken(),
+                          type: TypeSyntax(IdentifierTypeSyntax(name: .identifier("String"))),
+                          trailingComma: .commaToken()
+                        ),
+                        TupleTypeElementSyntax(
+                          firstName: .identifier("baaz"),
+                          colon: .colonToken(),
+                          type: TypeSyntax(IdentifierTypeSyntax(name: .identifier("String"))),
+                          trailingComma: .commaToken()
+                        ),
+                      ]),
+                      rightParen: .rightParenToken()
+                    )
+                  )
+                )
+              )
+            ]),
+            rightAngle: .rightAngleToken()
+          )
+        ),
+        leftParen: .leftParenToken(),
+        arguments: LabeledExprListSyntax([]),
+        rightParen: .rightParenToken()
+      )
+    )
   }
 
   func testSecondaryArgumentLabelDollarIdentifierInClosure() {