Changes in after-change-function can break lsp's error display

[aaronjensen]

Describe the bug
When a change is made in an after-change-function, lsp's error checking does not properly respect that change which leaves errors that are not errors visible. These don't go away until the buffer is saved.

It's certainly possible that this is a flycheck issue.

Downstream report: emacs-vs/auto-rename-tag#9

To Reproduce

Clone and follow instructions: https://github.com/aaronjensen/lsp-auto-rename-repro

Expected behavior
The error should disappear when there is no longer an error

Which Language Server did you use
typescript

OS
macOS

Error callstack
No error

[yyoncho]

https://github.com/aaronjensen/lsp-auto-rename-repro

This link is dead.

[aaronjensen]

@yyoncho sorry, forgot to make it public, please try again

[yyoncho]

As per docs

Buffer changes made while executing the before-change-functions' don't call any before-change or after-change functions. That's because inhibit-modification-hooks' is temporarily set non-nil.

This means that there is no way for lsp-mode to detect the change and send it to the server. The fix for that is auto-rename-tag to avoid doing any changes in after/before change hooks and execute then after the hooks have finished. One way to do that is to stash the changes and execute them in post-command hook.

[aaronjensen]

@yyoncho thanks! I just read that as well and got it working by firing the change in a timer afterwards, but a post-command hook seems to make even more sense.