FAQ.md

Frequently asked questions

How to import a specific version of Heapify?

Using npm, just specify the version when installing Heapify:

npm install heapify@0.6.0

Or using unpkg.com:

import {MinQueue} from "https://unpkg.com/heapify@0.6.0"

See unpkg for more importing options.

How do I import Heapify on a Node.js native ES6 module?

One could initially try this:

import {MinQueue} from "heapify";

But running it produces the following error:

import {MinQueue} from "heapify";
        ^^^^^^^^
SyntaxError: Named export 'MinQueue' not found. The requested module 'heapify' is a CommonJS module, which may not support all module.exports as named exports.
CommonJS modules can always be imported via the default export, for example using:

import pkg from 'heapify';
const {MinQueue} = pkg;

Developer note: the error is only seen in the Heapify production build. If I build it for development, the error does not appear. I think it has something to do with the uglify step.

This is the correct way of doing it:

import {MinQueue} from "heapify/heapify.mjs";

The main script exported by Heapify's package.json is a CommonJS module, but current Node.js versions still have trouble handling CommonJS modules imported by ES6 module scripts. There are ways to do it, but they are not very pretty.

The other way around it is to make it a two-step operation, like this:

import Heapify from "heapify";
const {MinQueue} = Heapify;

It is weird that this works at all while the one-line version doesn't, but it does 🤷.