Preview not working with Edge

Contribute Bug

AI-generated summary

Preview not working with Edge

A bug has been reported where the preview feature in Discourse does not work with Microsoft Edge. MikkoH first reported the issue, providing repro steps and an error message from the console. codinghorror was able to reproduce the issue on the latest version of Edge.

After investigation, joffreyjaffeux found the root cause to be related to Edge’s Regexp support, which causes a line of code in Discourse to fail. A polyfill fix has been proposed in PR #7460, courtesy of zogstrip. This fix is expected to prevent similar issues in other parts of the app.

1

We have a hosted Discourse, and today few people have complained that preview does not work with Edge (at least version 40)

Repro steps:

  • Create a new topic
  • Start writing a message
  • Preview area on the right stays blank (expected: preview shows formatted text as you type)
  • Console displays error message after each character typed, see image

image

6 Likes
2

Yep, I can repro on Edge latest.

Microsoft Edge 44.17763.1.0
Microsoft EdgeHTML 18.17763

Not sure when Edge turns into Chrome, looks like “Fall 2019”.

7 Likes
4

Ok this was kind of tricky to find the root cause, thanks to stellar debugging tools from edge.

So it happens edge has stellar Regexp support (a pattern is emerging) and will result in this:

Edge:

16
16762×108 25.4 KB

Chrome:

33
33848×112 11.5 KB

Making this line of Discourse fail https://github.com/discourse/discourse/blob/master/app/assets/javascripts/pretty-text/engines/discourse-markdown/text-post-process.js.es6#L24 spectacularly.

I was about to write a fix for this case, but @zogstrip found a polyfill, which is probably way better as it will prevent this from happening in any other place in the app.

https://github.com/discourse/discourse/pull/7460

Thanks for reporting this @MikkoH

9 Likes