olsen

Two of a kind check

Install

npm i olsen

Usage

In general, olsen(x, y)(func) ≡ func(x) === func(y).

var olsen = require('olsen');

olsen(1, 3)(isEven); // => true, both of kind "not even"
olsen(2, 4)(isEven); // => true, both of kind "even"

olsen(1, '1')(Number); // => true

olsen(1, 0.99999999999999999)(Number); // => true, 0.999... becomes exactly 1
olsen(1, 0.9999999999999999)(Number); // => false

olsen(0, 2 * Math.PI)(Math.cos); // => true

olsen(NaN, NaN)(function(x) {
  return x;
}); // => false, NaN !== NaN

See use case and accompanying tests.