Broken ngStep for input[type="number"] directive

[lucassus]

Do you want to request a feature or report a bug?

It's a bug

What is the current behavior?

For values like 1.16, 20.1 etc the input[type=number] field with ng-step="0.01" is marked as invalid.

Steps to reproduce:

1. Update to AngularJS version 1.6.0
2. Define an input[type=number] with ng-step="0.01"
3. For values like 1.16, 20.1 the field will be marked as $invalid

See a small demo: https://plnkr.co/edit/LW2BsaA7FfEVu9nB6RoG?p=preview

I believe it's a problem with floating points arithmetic and this little method https://github.com/angular/angular.js/blob/master/src/ng/directive/input.js#L1563

    // ...

    value = value * multiplier;
    stepBase = stepBase * multiplier;
    step = step * multiplier;
  }

  return (value - stepBase) % step === 0;

When for instance value = 1.16 and multiplier = 100 value * multiplier gives us 115.99999999999999 so the return expression returns false even when the given value is valid.

[gkalpak]

BTW, this also affects ngStep on input[range] (since both input types share their step implementation).

[benneq]

this should also be added to 1.6.0 (or is it just not included in 1.6.1 changelog? see: https://github.com/angular/angular.js/blob/master/CHANGELOG.md )

[gkalpak]

This has not been fixed yet. Once it is fixed, it will be included in 1.5.x and 1.6.x.