Dark mode isn鈥檛 working in Firefox. Also, if this helps, the implementation of dark mode on https://styled-system.com and https://jxnblk.com/blog/ does work in Firefox.
https://mybrowser.fyi/report/5ca793c4929f1c0014086d0d
Browser console error message:
11:42:00.950 SyntaxError: invalid regular expression flag s[Learn More] tag.js:32:14
<anonymous> tag.js:32
Webpack 18
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I don鈥檛 actually think that error has anything to do with dark mode not working. I cloned the repo and ran the docs, with the dark mode addition and at the previous commit without, but both have the same error. Here's the extended debug from running the docs in development:
extended debug output
SyntaxError: invalid regular expression flag s
../packages/remark-mdx/tag.js/<
/Users/knowler/code/github/mdx/packages/remark-mdx/tag.js:32
29 |
30 | exports.openCloseTag = new RegExp('^(?:' + openTag + '|' + closeTag + ')')
31 |
> 32 | exports.tag = new RegExp(
33 | '^(?:' +
34 | openTag +
35 | '|' +
../packages/remark-mdx/tag.js
http://localhost:8000/commons.js:178627:29
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
fn
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:100
97 | );
98 | hotCurrentParents = [];
99 | }
> 100 | return __webpack_require__(request);
101 | };
102 | var ObjectFactory = function ObjectFactory(name) {
103 | return {
../packages/remark-mdx/block.js/<
/Users/knowler/code/github/mdx/packages/remark-mdx/block.js:6
3 | //
4 | // MIT License https://github.com/remarkjs/remark/blob/master/license
5 |
> 6 | const {openCloseTag} = require('./tag')
7 |
8 | module.exports = blockHtml
9 |
../packages/remark-mdx/block.js
http://localhost:8000/commons.js:178135:29
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
fn
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:100
97 | );
98 | hotCurrentParents = [];
99 | }
> 100 | return __webpack_require__(request);
101 | };
102 | var ObjectFactory = function ObjectFactory(name) {
103 | return {
../packages/remark-mdx/index.js/<
/Users/knowler/code/github/mdx/packages/remark-mdx/index.js:3
1 | const isAlphabetical = require('is-alphabetical')
2 | const extractImportsAndExports = require('./extract-imports-and-exports')
> 3 | const block = require('./block')
4 | const {tag} = require('./tag')
5 |
6 | const IMPORT_REGEX = /^import/
../packages/remark-mdx/index.js
http://localhost:8000/commons.js:178454:29
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
fn
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:100
97 | );
98 | hotCurrentParents = [];
99 | }
> 100 | return __webpack_require__(request);
101 | };
102 | var ObjectFactory = function ObjectFactory(name) {
103 | return {
../packages/mdx/index.js/<
/Users/knowler/code/github/mdx/packages/mdx/index.js:3
1 | const unified = require('unified')
2 | const toMDAST = require('remark-parse')
> 3 | const remarkMdx = require('remark-mdx')
4 | const squeeze = require('remark-squeeze-paragraphs')
5 | const visit = require('unist-util-visit')
6 | const raw = require('hast-util-raw')
../packages/mdx/index.js
http://localhost:8000/commons.js:176150:29
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
fn
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:100
97 | );
98 | hotCurrentParents = [];
99 | }
> 100 | return __webpack_require__(request);
101 | };
102 | var ObjectFactory = function ObjectFactory(name) {
103 | return {
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
fn
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:100
97 | );
98 | hotCurrentParents = [];
99 | }
> 100 | return __webpack_require__(request);
101 | };
102 | var ObjectFactory = function ObjectFactory(name) {
103 | return {
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
fn
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:100
97 | );
98 | hotCurrentParents = [];
99 | }
> 100 | return __webpack_require__(request);
101 | };
102 | var ObjectFactory = function ObjectFactory(name) {
103 | return {
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
fn
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:100
97 | );
98 | hotCurrentParents = [];
99 | }
> 100 | return __webpack_require__(request);
101 | };
102 | var ObjectFactory = function ObjectFactory(name) {
103 | return {
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
fn
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:100
97 | );
98 | hotCurrentParents = [];
99 | }
> 100 | return __webpack_require__(request);
101 | };
102 | var ObjectFactory = function ObjectFactory(name) {
103 | return {
./gatsby-browser.js
/Users/knowler/code/github/mdx/docs/gatsby-browser.js:1
> 1 | export {wrapRootElement} from './src'
2 |
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
fn
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:100
97 | );
98 | hotCurrentParents = [];
99 | }
> 100 | return __webpack_require__(request);
101 | };
102 | var ObjectFactory = function ObjectFactory(name) {
103 | return {
./.cache/api-runner-browser-plugins.js
/Users/knowler/code/github/mdx/docs/.cache/api-runner-browser-plugins.js:8
5 | plugin: require('/Users/knowler/code/github/mdx/node_modules/gatsby-mdx/gatsby-browser.js'),
6 | options: {"plugins":[],"extensions":[".mdx",".md"],"remarkPlugins":[null,null]},
7 | },{
> 8 | plugin: require('/Users/knowler/code/github/mdx/docs/gatsby-browser.js'),
9 | options: {"plugins":[]},
10 | }]
11 |
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
fn
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:100
97 | );
98 | hotCurrentParents = [];
99 | }
> 100 | return __webpack_require__(request);
101 | };
102 | var ObjectFactory = function ObjectFactory(name) {
103 | return {
./.cache/api-runner-browser.js/<
/Users/knowler/code/github/mdx/docs/.cache/api-runner-browser.js:1
> 1 | const plugins = require(`./api-runner-browser-plugins`)
2 | const {
3 | getResourcesForPathname,
4 | getResourcesForPathnameSync,
./.cache/api-runner-browser.js
http://localhost:8000/commons.js:178878:29
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
fn
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:100
97 | );
98 | hotCurrentParents = [];
99 | }
> 100 | return __webpack_require__(request);
101 | };
102 | var ObjectFactory = function ObjectFactory(name) {
103 | return {
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
fn
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:100
97 | );
98 | hotCurrentParents = [];
99 | }
> 100 | return __webpack_require__(request);
101 | };
102 | var ObjectFactory = function ObjectFactory(name) {
103 | return {
0
http://localhost:8000/commons.js:189725:18
__webpack_require__
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:723
720 | };
721 |
722 | // Execute the module function
> 723 | modules[moduleId].call(module.exports, module, module.exports, hotCreateRequire(moduleId));
724 |
725 | // Flag the module as loaded
726 | module.l = true;
(anonymous function)
/Users/knowler/code/github/mdx/docs/webpack/bootstrap:790
787 |
788 |
789 | // Load entry module and return exports
> 790 | return hotCreateRequire(0)(__webpack_require__.s = 0);
791 |
(anonymous function)
http://localhost:8000/commons.js:1:11
I cannot reproduce this in prod at https://mdxjs.com in Firefox 65:

Unable to confirm locally due to #542.
Working on a fix for #542 @macklinu! The fix for this issue was #532 (didn't realize it also fixed this).