editor: Apply Copilot suggestion before fixing indent

[mmtftr]

Release Notes:

• Fixed copilot code not getting accepted when tabbed #4549.

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[mmtftr]

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[as-cii]

Thanks for the contribution, @mmtftr! Unfortunately, this breaks the previous behavior that caused Zed to only insert the leading whitespace when hitting tab inside of a line's indentation. Can you adjust this PR to fix the issue but also preserve that previous tab behavior?

[mmtftr]

@as-cii Thanks for the clarification. I don't quite understand the problematic behavior. Is there a test or an issue that I can reference for this behavior? I'd love to write a test to cover this if there isn't any.

EDIT: nvm there are failing tests so I'll check them out

[mmtftr]

So, is the wanted behavior as so:

• If copilot suggestion has lower indent and we have an active suggestion, accept the copilot suggestion even if we're before suggested indent.
• Otherwise, first indent to suggested indent, accept the suggestion on the next tab.

If this is the case, I'll work on implementing this behavior and adding tests for it.

[mmtftr]

• Rebased on upstream/main
• Implemented the logic mentioned above if copilot suggests lower indent than suggested, then avoid auto-indent
• Wrote tests according to the requirements mentioned above.
  • Also checked locally that the test fails if the editor change is reverted.

[mmtftr]

@as-cii could you check this one again?

[ConradIrwin]

Sorry for the lack of response on this PR.

I am going to close it for now as it conflicts with everything, but I do think this is something we should figure out how to fix. Feel free to re-open and assign me if you're still interested in working on this.