Current Behavior

When importing into a worker environment the following runtime error occurs

Uncaught ReferenceError: window is not defined
    at node_modules/.pnpm/[email protected][email protected]/node_modules/isomorphic-dompurify/browser.js (isomorphic-dompurify.js?v=650fd638:949:22)

Change in behavior

The runtime error does not occur and DOMPurify is accessible both as a export
and on self.DOMPurify/globalThis.DOMPurify in workers

Developer Notes

There are probably a dozen different ways to fix this issue, the one chosen was
picked for being the one with the fewest number of changes while being
backwards compatible all the way back to browser versions from 2012 (Firefox
back to 2004)

See: https://developer.mozilla.org/en-US/docs/Web/API/Window/self#examples

Other approaches considered

• Using typeof window !== "unefined"
  • This method of determining if the window exists and if this code is
    executing in a worker was considered however after this check was done the
    split in exuection after this was detected would have either needed to use
    self or pollyfil window on self. Since self always works it seemed
    more straight forward to just always use it instead of window

Example:

const globalObject = typeof window !== "undefined" ? window : self;
module.exports = globalObject.DOMPurify || (globalObject.DOMPurify = require('dompurify').default || require('dompurify'));

• Using globalThis
  • This method would be better if trying to target the same code on server and
    browser however it is a much newer feature and not available on all platforms
    (ie, React Native, etc.)

Example:

module.exports = globalThis.DOMPurify || (globalThis.DOMPurify = require('dompurify').default || require('dompurify'));

• Using typeof window !== "undefined" but not assigning to self.DOMPurify
  • This would simply remove the accessing of window in worker environments
    effectively killing the polyfil nature of this in worker environments but
    still allowing the import

Example:

const dompurify = require("dompurify")

if (typeof window !== "undefined") {
  window.DOMPurify = window.DOMPurify || dompurify.default || dompurify;
}

module.exports = typeof window !== "undefined" ? window.DOMPurify : dompurify.default || dompurify;

• Using optional chaning
  • This would have had the same outcome of not having DOMPurify accessible on
    self/globalThis as the previous method however it would rely on a feature
    only aviable in newer JavaScript environments.

Example:

const dompurify = require("dompurify")

if (typeof window !== "undefined") {
  window.DOMPurify = window.DOMPurify || dompurify.default || dompurify;
}

module.exports = window?.DOMPurify || dompurify.default || dompurify;

• Using null coalescing
  • Again this feature is very new and not supported in every environment

const dompurify = require("dompurify")

if (typeof window !== "undefined") {
  window.DOMPurify ??= dompurify.default || dompurify;
}

module.exports = window?.DOMPurify : dompurify.default || dompurify;

fixes: #240