"Files changed" view in pull request not loading files and comments on large PR

[matteoolivi]

I have a PR that is really large: 17 files changed, 2.7k lines of code added, 0 removed, 190 review comments.

When I click in the "files changed" view to add comments or reply to existing ones, the view loads only 2 of the 17 files (and of course, it doesn't show the comments on those 15 files that are not displayed):

It hangs indefinitely, or crashes after some time. Other PRs against the same repo, of normal size, are still working perfectly well (the "files changed" view displays everything).

This happens for Chrome, Safari and Firefox, and is happening to all of my colleagues who are trying to look at the PR, not just me (so it's not due to my machine doing something weird).

I'm not sure what's causing the issue exactly, but before there was such a big number of comments the "files changed" view was working perfectly fine.

I know, PRs this big are an anti-pattern. Yet, I feel like github should work well even in this case. Can something be done about it? How can I find out more precisely what's causing the issue?

[matteoolivi]

cc @mkfdoherty

[theetrain]

I also face this issue in pull requests with 50 files. Most of those files only have a handful or a few dozen lines of code changes in their diffs. Sometimes the page loads fine, but after submitting 20 comments in a PR review, my colleague would push more commits and then the /files page hangs, similarly to what was described by OP.

On a 2015 Macbook pro with 16GB RAM running Chrome 98, my page crashes when loading /files in a PR:

On a custom PC running Windows 10 with 16 GB RAM, it also crashes but with more details related to memory::

The page does work on a 2021 Macbook Pro M1 Max with 64 GB ram, but I shouldn't need 64 GB ram.

Of course I agree pull requests should be small, but sometimes they go through journeys with multiple comments spanning complex commit diffs that are outdated, and the journey to go back and resolve older comments should be possible, such as utilizing the Conversations tab at the top of the page. It's great that GitHub continues to improve the tools in PR reviews, and I hope this performance issue can be addressed for large-scale PRs.

[willsmythe]

Can you try viewing this PR again? We fixed a bug last week that should resolve this.

[theetrain]

Performance seems to have improved, thank you.

[billxinli]

I am getting page is unresponsive with large PRs.

I am running Chrome on a 5950x with 128GB of RAM.

I am happy to provide the link to the PR from above to GH if required.

[willsmythe]

Can you try viewing this PR again? We fixed a bug last week that should resolve this.

[FaithOmbongi]

Same situation here.
I've tested on both Chrome and Edge and in Incognito mode, but the freeze is prevalent. The PR is 21 files long.

[ravenshining]

I found my way here because of the same issue, but I deal with much larger PRs. ~135 files changed, +1500 lines & -500 lines one I've got open right now, and that's the small slice of something five times larger so it's easier to review version. I wanted to break it up even smaller, but was told not to as that would create too many PRs to sort through.

It'd be really nice if it didn't auto-expand everything to begin with on a large PR, and refrained from loading things until you click to expand them in the left pane. Trying to load everything at once hangs the browser and eats data unnecessarily.

[tanchekwei]

I'm experiencing the same issue. Unresponsive and unable to navigate the file tree for the pull request:
https://github.com/files-community/Files/pull/10283/files