Validate AI feedback points against PR files before posting review comments

[chinar-amrutkar]

Problem

When the AI returns feedback points, the file_name and line_numbers values aren't validated against the actual PR diff before being sent to the GitHub API. This causes silent failures:

• If the AI references a file not in the PR, GitHub rejects the review
• If the AI returns a line number outside the valid range, GitHub rejects the review
• When this happens, the POST /repos/{owner}/{repo}/pulls/{pull_number}/reviews call returns 422 and no comments get posted at all -even valid ones are lost

Steps to reproduce

1. Trigger a review on a PR where the AI returns a feedback point referencing a file not in the diff, or a line number beyond the file length
2. The review request to GitHub fails with 422
3. No review comments appear on the PR

Suggested fix

In handleLabeled.ts, after getting the AI feedback and before calling postInlineComments, filter each feedback point:

• Verify point.file_name matches a file returned by getPRFiles
• Verify each line number in point.line_numbers is within the range of lines in that file's patch

This could be a utility function like validateFeedbackPoints(points: FeedbackPoint[], files: PRFile[]) that returns only the valid points. Invalid points could be logged to console for debugging.

[Droid-An]

Hi, thank you for the suggestion, it's really useful.
From my experience AI never invented new file names or lines, all it's comments was spot on, and that's why I didn't consider doing this validation.
But why not to have it for peace in mind. I implemented it in this branch