iframe sometimes gets disconnected

[Rich-Harris]

Unfortunately I think #309 has made the site less robust — I'll occasionally run into blank pages that don't recover. It's hard to reproduce, but I've seen it a number of times.

If we don't reinstate the same behaviour we had before, I wonder if there's something smart we could do with e.g. unload events to track whether or not we're currently connected to the iframe (e.g. if the iframe was unloaded, making an edit should forcibly refresh it)

[tomoam]

@Rich-Harris
Is what you saw a completely blank page or a default error page like 500 | Internal Error?

If it is the default error page, I have seen it too, and it seems to happen most often when the browser's developer tools are open. If the Developer Tools are in a closed state, it seems to recover automatically. (Of course, I still think we should fix it).

I have never seen a completely blank page, but if you have, please let me know. It might give us a clue.

I will tackle this, but it will probably take a while. If you need a fix sooner to prepare for your Front End Master Course next week, let me know and I will revert #309 first.
(I watched the Dev Vlog. This is off-topic, but thanks for mentioning me, I'm very happy😊).

[Rich-Harris]

I've seen completely blank pages that require clicking the reload icon. If I manage to figure out a way to reproduce it consistently I'll update this issue.

This is off-topic, but thanks for mentioning me, I'm very happy😊

Yeah! Your contributions to the project have been awesome and very much appreciated

[Rich-Harris]

Just realised that we also don't refresh the page if the fallback error page is shown (as in https://learn.svelte.dev/tutorial/fallback-errors). The approach above might fix that

[tomoam]

In the case of fallback errors, reloading the iframe might cause flash in dark mode.
How about automatically inserting __client.js in /src/error.html as in /src/app.html?

[Rich-Harris]

great idea! that'll definitely help in the fallback error case. opened #343

[Rich-Harris]

merged #345 so i'll close this and hope the issue doesn't reappear in another form