//// [genericFunctionCallSignatureReturnTypeMismatch.ts] interface Array {} var f : { (x:T): T; } var g : { () : S[]; }; f = g; var s = f("str").toUpperCase(); console.log(s); //// [genericFunctionCallSignatureReturnTypeMismatch.js] var f; var g; f = g; var s = f("str").toUpperCase(); console.log(s);