(jupyter) Console log in jupyter notebook prints only last message

[zph]

Versions of Deno affected (non-exhaustive):

• 8fcc263 near tip of main
• 1.44.4
• 1.43.6

Working versions:

• 1.43.5
• 1.43.3
• 1.43.0
• 1.42.4
• (etc)

The regression occurred between v1.43.5 and 1.43.6: v1.43.5...v1.43.6

Expected behavior: console.log will print all messages from a cell

Actual behavior: console.log prints only last message from a cell

The changes to jupyter occurred in: 93d7b37 as part of refactoring the jupyter integration.

@rgbkrk Do you have a hunch about where this is happening since you authored the work in 93d7b37?

[rgbkrk]

Yeah this is bound to be in that stdio sender. Working on reproducing now.

[rgbkrk]

This only reproduces in VS Code. In Jupyterlab, classic, and Zed Nightly it all displays normally.

VS Code

Zed Nightly

Jupyter Lab

[lucacasonato]

@rgbkrk Is this something we should change in deno jupyter, or do you think this is an upstream VS Code issue?

[rgbkrk]

It looks like it's on the VS Code side. I'll dig in to find out why though as all clients should be treating the protocol the same.

[sinedied]

Can it also be the reason why errors are not being displayed in the console?

I'm only using VS Code and currently I'm unable to see errors in code cells. Let me know if you think I should open a separate issue, but I may get nothing because only the last print (newline?) is shown.

[mrbelderock]

Just commenting to say I have the same issue. VSCode, Deno 1.44.1 - console.log prints only last line and (so?) errors don't print either.

[rgbkrk]

@DonJayamanne -- I haven't discovered yet why VS Code is treating messages differently than other jupyter frontends. Can you check this out?

[sinedied]

I have an extra hint that may be useful for the investigation: it's not only the last log that is shown, but only the last one from the same tick.

The following code:

console.log("1");
console.log("2");
window.setTimeout(() => {
  console.log("3");
});

outputs

2
3

in VS Code. So console logs in different ticks are still visible.

[DonJayamanne]

Root cause is here, #24737
Apologies for taking so long

[rgbkrk]

Egg on my face, I'm going to go fix this now.

[bartlomieju]

Closed in #24762