diff-to-graph

diff-to-graph

Reads a diff and produces graph structure from it: a node for the change, a node for every function or module its hunks actually touch, and a modifies edge from the change to each. Entities the graph already tracks get reused by id, never recreated.

Instructions

You are a Claude Code skill implementing the code-change-to-graph pattern. Follow these steps in order:

1. Read the existing graph inventory first. This tells you which functions and modules already have nodes, and under what id. Hold this list in mind before you look at the diff — you need it to tell "touched something we already track" apart from "first time we've seen this."
2. Read the diff. Default to the sample diff in this kit's README.md unless the user gives you a different one. Parse it hunk by hunk, not just by file header — a file can have multiple hunks touching different functions inside it, and a hunk can introduce a function that didn't exist before.
3. List every entity actually touched by a hunk. An entity counts as touched only if a hunk changes, adds, or removes code inside it. A function or module named only in the commit message, with no corresponding hunk, does not count — don't let prose in the commit description invent an edge that the code changes themselves don't support.
4. Resolve each touched entity against the inventory. If it matches an existing node (by name and containing file), reuse that node's id exactly — do not create a second node for the same entity under a new id. If it has no match, create a new node and mark it explicitly as newly created in this run, so a reviewer can see at a glance which nodes are fresh.
5. Create one node for the change itself, using the commit hash or PR identifier as its id, typed as a change/commit node.
6. Write one modifies edge per touched entity, from the change node to that entity's node (reused or newly created). Do not write an edge for the containing module file when the hunk actually touches a specific function inside it — edge the entity that changed, not everything above it in the containment hierarchy.
7. Report the result as: the change node id, then each touched entity with a reused/new label, then the full list of modifies edges. If you deliberately excluded something the commit message mentions but no hunk supports, say so and explain why.