pi-patch-edit

A git-diff/patch-inspired edit tool for the pi coding agent. Shadows pi's built-in edit with a unified-diff interface.

What it does

Replaces pi's edit tool (exact oldText/newText replacement) with one that accepts a unified diff — the format git diff produces, and the format LLMs are most fluent in.

@@ -10,7 +10,7 @@ class Foo {
     def bar(self):
-        return 1
+        return 2

• Multiple hunks for one file in a single call
• Fuzzy matching: tolerates line-number drift and trailing-whitespace differences via context lines (powered by the diff npm package)
• Section-header guidance: the text after @@ (e.g. class Foo:) validates the target scope and corrects obviously-wrong line numbers
• Line numbers respected: oldStart is treated as a reliable hint (from git diff/grep, or approximately-right LLM guesses)
• Edits only: existing files only. Use write to create files, bash (mv/rm) for renames/deletions

Install

pi install git:github.com/JerryAZR/pi-patch-edit

Or try without installing:

pi -e git:github.com/JerryAZR/pi-patch-edit

The tool shadows the built-in edit automatically (pi prints a shadow warning on load).

How it works

1. Parse the unified diff with diff's parsePatch; reject multi-file diffs (the tool takes an explicit path).
2. Validate captions: if a hunk's section header (text after @@) doesn't appear as a line in the file, reject the whole patch — likely the wrong file.
3. Correct oldStart: if a captioned hunk's oldStart points before the caption's first occurrence (nonsensical — the hunk can't be inside a scope that starts later), re-derive it to the first context line at/after the anchor. Otherwise keep oldStart as-is.
4. Apply all hunks in one batched applyPatch call on the whole source.

Development

npm install      # installs diff + pi peer deps for typecheck
npm test         # 26 tests, no external deps
npm run typecheck

License

MIT