Add FunctionParameterWithEllipsis test case

Author: bannzai

unittests/Syntax/DeclSyntaxTests.cpp

@@ -324,6 +324,34 @@ TEST(DeclSyntaxTests, FunctionParameterWithAPIs) {
   }
 }
 
+TEST(DeclSyntaxTests, FunctionParameterWithEllipsis) {
+    auto ExternalName = SyntaxFactory::makeIdentifier("for", {},
+                                                      Trivia::spaces(1));
+    auto LocalName = SyntaxFactory::makeIdentifier("integer", {}, {});
+    auto Colon = SyntaxFactory::makeColonToken(Trivia::spaces(1),
+                                               Trivia::spaces(1));
+    auto Int = SyntaxFactory::makeTypeIdentifier("Int", {},
+                                                 Trivia::spaces(0));
+    auto Ellipsis = SyntaxFactory::makeEllipsisToken({},
+                                                     Trivia::spaces(1));
+    auto Comma = SyntaxFactory::makeCommaToken({}, {});
+    
+    {
+        SmallString<48> Scratch;
+        llvm::raw_svector_ostream OS(Scratch);
+        getCannedFunctionParameter()
+        .withFirstName(ExternalName)
+        .withSecondName(LocalName)
+        .withColon(Colon)
+        .withType(Int)
+        .withEllipsis(Ellipsis)
+        .withDefaultArgument(llvm::None)
+        .withTrailingComma(Comma)
+        .print(OS);
+        ASSERT_EQ(OS.str().str(), "for integer : Int... ,");
+    }
+}
+
 #pragma mark - parameter-list
 
 TEST(DeclSyntaxTests, FunctionParameterListMakeAPIs) {