automatic reload when file changes externally

[dead10ck]

It would be great if it were detected when the file you are editing has been changed externally, and if possible, automatically reload the file.

I imagine it could work similarly to vim and kakoune, i.e. if there are no modifications that have yet to be written, just reload the file, and treat it as a single modification that can be undone. If there are modifications that haven't been written yet, prompt the user about what they would like to do:

• Ignore the changes, keep that's in the editor buffer, and let a write happen over the external change, whatever it was
• Reload the file anyway, essentially "adding" to the unsaved changes

[archseer]

See #588

[greg-enbala]

Humbly, I prefer helix always alert me before it reloads an open file even if there are no changes to the opened file.

• If there are unsaved changes i think it's clear that you may not want to lose them
• If the document hasn't been changed since it was opened, perhaps I'm deliberately keeping it open while I look at something else from another branch
• If the document has been changed since it was opened and saved, perhaps I accidentally checked out an old version or perhaps i deliberately checked out an old version and have it open in another editor.

Long story short there are always good reasons for me to have helix hold on to a version of the file that's not the current version in the file system.

[jtrees]

Just some quick feedback:

I'm currently trying Helix as an alternative to Kakoune and the lack of file watching really hurts. I frequently have several windows open with Helix where I work on the same files. Since there is no server-client architecture, the buffers get out-of-sync and make this workflow virtually unusable.

I suppose the most viable workaround is to use splits in a single Helix instance, instead of letting my window manager handle the windows.