isabella232 / memoize-js

A JavaScript library for memoizing the result of a pure function

@bigcommerce/memoize

This library can be used to memoize the result of a pure function.

Unlike the default memoize function provided by Lodash, it can be applied to functions that accept multiple non-primitive arguments. It can also be configured to expire its cache after certain number of unique calls. By default, it compares object-based arguments shallowly; but it can be configured to compare arguments strictly or deeply depending on your usage requirement.

Install

You can install this library using npm.

npm install --save @bigcommerce/memoize

Usage

To memoize a function:

function fn(a, b) {
    return { a, b };
}

const memoizedFn = memoize(fn);
const result = memoizedFn({ message: 'hello' }, { message: 'world' });
const result2 = memoizedFn({ message: 'hello' }, { message: 'world' });

expect(result).toBe(result2);

To set a limit on the cache size:

function fn(a, b) {
    return { a, b };
}

const memoizedFn = memoize(fn, { maxSize: 1 });
const result = memoizedFn({ message: 'hello' }, { message: 'world' });

// This call will expire the cache of the previous call because it is called with a different set of arguments
const result2 = memoizedFn({ message: 'hello' }, { message: 'foobar' });
const result3 = memoizedFn({ message: 'hello' }, { message: 'world' });

expect(result3).not.toBe(result);

There is a convenience method for setting the cache size to one:

const memoizedFn = memoizeOne(fn);

To use a different argument comparison function:

const memoizedFn = memoize(fn, { 
    isEqual: (a, b) => a === b,
});

Contribution

To release:

npm run release

To see other available commands:

npm run

License

MIT