ES6类静态方法vs函数

Question

I am using NodeJS and going to write some utility functions. I think of two options here.

The first one is the traditional approach, ie

module.exports = {
    random: () => Math.random(),
};

And the second option is to use ES6 class with static methods, eg

class MyMath {
    static random() {
        return Math.random();
    }
}
module.exports = MyMath;

From programming/unit testing's perspective which one is better? Or they are pretty much the same because ES6 class essentially is a syntactic sugar?

Update: Thanks for the people who commented. I saw those questions asking class static method vs instance method, or prototype methods vs object method but mine is more like class static method vs Object method.

Answer 1

Using static-only classes as namespaces in JavaScript is the remnant of languages where a class is the only available entity. Modules already act as namespaces.

In case singleton object is needed, object literal should be used:

module.exports = {
    random: () => Math.random(),
};

There's already exports object that can be used:

exports.random = () => Math.random();

Or with ES modules:

export const random = () => Math.random();

Answer 2

With the class syntax you might give more than you really intended, it is a constructor that can be invoked with new , while with the object literal syntax you give a non-function object. As that is really what you want to expose, go for that.

Answer 3

Classes with only static methods are the same as a bunch of isolated functions. In this case you probably don't need to use it. As for unit tests it is pretty much the same since classes with only static methods does not differ that much from functions.