3.19.0 appears to break server-side rendering by relying on window

[cr3ative]

Hi there,

I'm really sorry that I couldn't find a simple way to replicate this with demo code, but hopefully I can be descriptive.

We use a mixed Preact/React stack at the moment, and use preact-render-to-string to dump out the DOM to provide server-side rendering.

When our packages automatically updated to include preact-compat 3.19.0, SSR broke, with the following stack trace:

ReferenceError: window is not defined
    at evalmachine.<anonymous>:7654:360
    at ./node_modules/preact-context/dist/context.min.js (evalmachine.<anonymous>:7654:22)
    at Object../node_modules/preact-context/dist/context.min.js (evalmachine.<anonymous>:7654:118)
    at __webpack_require__ (evalmachine.<anonymous>:20:30)
    at Module../node_modules/preact-compat/dist/preact-compat.es.js (evalmachine.<anonymous>:6985:72)
    at __webpack_require__ (evalmachine.<anonymous>:20:30)
    at Module../app/node_modules/@buzzfeed/react-components/dist/module/lib/components/CdnImage/index.js (evalmachine.<anonymous>:119:63)
    at __webpack_require__ (evalmachine.<anonymous>:20:30)
    at Module../app/static/js/render_kit/components/ResultCard.js (evalmachine.<anonymous>:2639:133)
    at __webpack_require__ (evalmachine.<anonymous>:20:30)

This rendering kit uses a React component (CdnImage) and preact-compat fails when this line, in that component, is imported:

import React, { Component } from 'react';

Something in there is relying on window and we've bisected it to 3.19.0

I hope that helps. I'm sorry again for being so vague.

[developit]

Hi Paul - just wanted to apologize for the radio silence on this issue.

You're right that this was introduced in 3.19, since the error is coming from createContext, which was the most recently merged PR (#529). It looks like the issue is actually a build configuration error in preact-context - I'll try to find a fix there.

[developit]

This should be fixed!