port-features

name: port-featuresdescription: Port a feature from an existing repository by copying its actual code and editing the copy, so its bug fixes and behavioral nuances survive. Use when asked to copy or port an existing feature (especially an exact copy), when moving one into a different framework or host, or when a previous reimplementation missed upstream behavior.

Port Features

Upstream code is the spec. Every guard, ordering, timeout, and odd branch in it may be a bug fix someone already paid for. A rewrite from your understanding of the feature drops the ones you didn't notice.

1. Start from the code. Get a local checkout of upstream with its history, pin the exact commit, and read the feature's real files, not a screenshot, summary, or fetched snippet. Follow imports and callers until you know which files make up the feature.
2. Read the history. Read path-scoped git log, following renames, for those files, and read the fixes. Before changing or dropping anything that looks unnecessary, find out from history why it is there.
3. Copy, then edit. Copy the exact files, with their tests, into the destination first. Then delete what the destination does not need and change imports and host bindings. Keep upstream's structure and algorithms even where you would have written them differently. Never write your own version in their place.
4. Diff back. Diff the result against the pinned source and justify every change. When a carried-over test fails, fix the adapter before touching the algorithm or the test.

Done when the destination is the pinned upstream code plus a diff you can account for, and the handover names the upstream commit and every deliberate difference. Never call a rewrite a port.