Enum-class.js NPM

enum-class.js

enum-class.js gives JavaScript the power of strongly-typed enums, inspired by modern C++ enum classes, Python namedtuples and Java enums, with dynamic JavaScript sugar sprinkled on top.

Usage

Similar to the flexibility of the namedtuple constructor in Python, you can pass the members as ['A', 'B', 'C'], 'A, B, C' or 'A B C':

const Color = EnumClass('Color', 'Red, Green, Blue');
const Food = EnumClass('Food', 'Ham Spam');

But also optionally associate values with the enum members:

const Favorites = EnumClass('Food', {
    Red: function() { console.log('Every member has a value!'); },
    Spaghetti: [1, 2, 3],
    Google: "I'm immutable after configuration."
});

The special thing is that members of enum classes are ... instances of themselves :scream:

console.log(Color.Red instanceof Color); // true

As such, we get maximum type safety:

console.log(Color.Red === Favorites.Red); // false

But also all the good reflection stuff:

for (let member of Color) {
  console.log(member.name); // Red, Green, Blue
  console.log(member.toString()); // Red, Green, Blue
  console.log(member.value); // undefined, because we didn't pass an object
}

And extensibility:

Color.add('Orange', 'value');

console.log(Color.length === 4); // true
console.log(Color.contains('Orange')); // true
console.log(Color.isMember(Color.Red)); // true
console.log(Color.isMember(Favorites.Google)); // false