egal - npm Package Versions

Fixes deepEgal to consider Array.prototype equivalent to an empty array. JavaScript is a prototypical language after all and the prototype of an array is an array.

Fixes egal to consider two objects inheriting from null without constructor properties, but valueOf functions, as plain objects and not as value objects.

Adds support for comparing value objects that return compound values from their valueOf function. That is, you no longer need to return a single primitive value from valueOf, but merely a more primitive one than before:

function Point(x, y) { this.x = x; this.y = y }
Point.prototype.valueOf = function() { return [this.x, this.y] }
egal(new Point(42, 69), new Point(42, 69)) // => true
egal(new Point(42, 69), new Point(13, 42)) // => false

Adds deepEgal for comparing plain objects and arrays recursively.
It's still type-safe, so value objects and instances of classes nested in plain objects as compared as egal — by value if possible (same constructor and has a valueOf function), by reference (===) otherwise.

var deepEgal = require("egal").deepEgal
function Model(name) { this.name = name }

deepEgal(42, 42) // => true
deepEgal({name: "John"}, {name: "John"}) // => true
deepEgal({stats: {age: 13}}, {{stats: age: 13}}) // => true
deepEgal([1, 2, 3], [1, 2, 3]) // => true
deepEgal(new Model("John"), new Model("John")) // => true
deepEgal(new Date(2000, 5), new Date(2000, 5)) // => true

No longer considers a primitive and boxed object of the same value to be equivalent.
Two boxed objects of the same value will remain equivalent.

egal(true, new Boolean(true)) // => false
egal(new Boolean(true), new Boolean(true)) // => true

Boxed objects tend to be very error prone and it's best you stick to primitives only. The following is a small example of problems with boxed objects:

new String("a") == new String("a") // => false
new Boolean(true) == new Boolean(true) // => false
Boolean(new Boolean(false)) // => true
!!(new Boolean(false)) // => true