Typescript types on rest params from argument -


is possible tell typescript types of rest params based on signature of function passed?

function myfunc(a: string, b: number) { /* ... */ }  function callfn(passedfn: (args...: any[]), ...args: any[]) {   passedfn(...args) }  callfn(myfunc, 1, 2) // should warning

following code shows compile error, because lose type control under args.

interface icallback  {      (a: string, b: number): void }  class test {         public callfn(passedfn: icallback, ...args: any[]): void     {         passedfn(args); // error         passedfn("1", 2);     }     }  class callback {         public myfunction = (a: string, b: number) =>      {          alert("it's working");     } }  let testintance = new test(); let callbackintance = new callback();  testintance.callfn(callbackintance.myfunction, 1, 2);

you have handle exceptions , try parse typed variables.

class test {         public callfn(passedfn: icallback, ...args: any[]): void     {         //passedfn(args); // error          let hastwoarguments = args && args.length && args.length === 2;         if(!hastwoarguments)         {             return;         }          let firstargument: string = args[0];         let secondargument: number = parseint(args[1]);          passedfn(firstargument, secondargument);     } }

see demo


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