Is there a node.js library that verifies arguments list to check if they conform to the arguments I want.
Like here's a function I want to write:
function my(a [,b], done);
a is required, and should be an object. b is optional but should be an array. done is the callback and should be a function.
Is there a library that would do all the necessary checks and substitutions (if(!done)done=b) etc automatically?
There's three that I found;
var typed = require('typed-function');
// create a typed function
var fn1 = typed('number, *': function (a, b) {
return 'a is a number, b can be anything';
});
https://github.com/josdejong/typed-function
var accept = require("check-args-lib")
var fn = accept(Number).accept(String).to(function(dyna) {
// do something with dyna...
// If the type checking is enabled, you can now be sure it is
// defined and it is a number or a string
});
https://github.com/artarf/check-args
var argue = require('argue');
function foo() {
var sig = argue(arguments);
switch(sig) {
case 'sbnf':
var mystr = arguments[0];
var mybool = arguments[1];
var mynum = arguments[2];
var myfunv = arguments[3];
// we got a string, boolean, number, and function
break;
case 'nnnn':
// we got four numbers
break;
case 'ord-':
// we got an object, regexp, date, and null
break;
default:
// you get the idea
}
}
I'd say I like check-args most out of the three as it provides a way to remove this sort of code in production very easily. typed-function has a pretty nice syntax, and argue is alright too, but is more like a helper for doing things like typeof checks than actually throwing any error.
