Add test for empty arguments and arity filtering

Author: JsonFreeman

src/harness/fourslash.ts

@@ -944,11 +944,6 @@ module FourSlash {
             this.validate("error", message, renameInfo.localizedErrorMessage);
         }
 
-        //private getFormalParameter() {
-        //    var help = this.languageService.getSignatureHelpItems(this.activeFile.fileName, this.currentCaretPosition);
-        //    return help.formal;
-        //}
-
         private getActiveSignatureHelpItem() {
             var help = this.languageService.getSignatureHelpItems(this.activeFile.fileName, this.currentCaretPosition);
 

tests/cases/fourslash/signatureHelpOnOverloadsDifferentArity3.ts

@@ -0,0 +1,26 @@
+/// <reference path='fourslash.ts'/>
+
+////declare function f();
+////declare function f(s: string);
+////declare function f(s: string, b: boolean);
+////declare function f(n: number, b: boolean);
+////
+////f(/**/
+
+goTo.marker();
+verify.signatureHelpCountIs(4);
+verify.currentSignatureHelpIs("f(): any");
+verify.currentSignatureParamterCountIs(0);
+
+edit.insert(", ");
+verify.signatureHelpCountIs(4);
+verify.currentSignatureHelpIs("f(s: string, b: boolean): any");
+verify.currentSignatureParamterCountIs(2);
+verify.currentParameterHelpArgumentNameIs("b");
+verify.currentParameterSpanIs("b: boolean");
+
+// What should the intended behavior be if there are too many arguments?
+edit.insert(", ");
+verify.signatureHelpCountIs(4);
+verify.currentSignatureHelpIs("f(): any");
+verify.currentSignatureParamterCountIs(0);