This is the inverse off the popular is-thirteen library. Though make no mistake, on this side of the line we favor non thirteen numbers and believe that 12 is the new 13.

Usage

var is = require('is-not-thirteen');

// This adopts the DSL from the is-thirteen lib but
// adds a "not" operation
is(12).not.thirteen(); // true
is(12).not.roughly.thirteen(); // true
is(1).not.within(10).of.thirteen(); // true

The most important API function

// Check to see if a given number is not better than twelve
is(13).not.betterThanTwelve(); // true
is(10).not.betterThanTwelve(); // true
is(12).not.betterThanTwelve(); // DONT DO THIS, will collapse the universe