If two arguments are passed but on the 2nd is verified the resulting error is misleading

[leggetter]

Say I've the following:

var using = require( 'typester' ).using;

function Thing( name, number ) {
  using( arguments )
    .verify( 'number' ).fulfills( Number );
}

Should this always fail because I'm not also checking the name argument which is part of arguments?

In this scenario I'm seeing an error stating that the number isn't fulfilling Number. When I think it should actually be saying something like All arguments weren't checked.

If I instead do:

var using = require( 'typester' ).using;

function Thing( name, number ) {
  using( arguments )
    .verify( 'name' ).fulfills( String );
}

I get the following error:

ArgumentError: only 1 argument(s) verified but 2 were provided

Which is much more informative. Maybe just some sorting check problem?

[dchambers]

Hi @leggetter,

Because of the chained fluent API typester currently has, we never know when type verification will come to an end, and so fixing your issue is not as easy as you might imagine.

Even the message you do currently like (ArgumentError: only 1 argument(s) verified but 2 were provided) is only provided to the developer the next time using() is invoked, and involves some hokey code to make it work. If all type verification was delayed like this then we'd never fail-fast, the call-stack would always be wrong, and developers would potentially miss real issues.

However, it just so happens that I'm about to change the typester API to further improve performance, and this change also happens to make it much easier to address your issue, and always fail-fast with a valid call-stack. You can take a look at the updated README.md on the more-performant-typing branch to see what the API is going to look like for yourself.