@ossl-dev/differens-correlate

Cross-file move and rename detection. After per-file diffing, it correlates deleted nodes from one file with inserted nodes in another and reports them as cross-file Moves: “this function was moved, not deleted and copy-pasted.” Only named nodes are correlated. An anonymous fragment that is structurally identical in two files is not reported as a move. Install:

npm install @ossl-dev/differens-correlate

Exports

Export	Kind	Description
`correlate`	function	`FileChanges[]` → `CrossFileResult`
`FileChanges`	interface	`{ filePath, actions }`: one per-file diff result
`CrossFileResult`	interface	`{ moves: CrossFileMatch[] }`
`CrossFileMatch`	interface	A detected move/rename
`CorrelateOptions`	interface	`{ renameSimilarityThreshold }`

correlate

correlate(fileChanges: FileChanges[], options?: Partial<CorrelateOptions>): CrossFileResult

// CrossFileMatch:
// { node: Node; fromFile: string; toFile: string;
//   modified: boolean; similarity: number }

renameSimilarityThreshold defaults to 0.6. It is the minimum similarity for a partial match to count as a move. similarity is 1.0 for exact matches. modified is true when the node changed during the move. Nodes that stay unmatched are left as the plain Delete/Insert the per-file diff already reported.

The three-stage algorithm

Structure hash buckets. All deleted and inserted named nodes are bucketed by structureHash (kind + children, no labels). Only structurally identical candidates are compared.
Content hash exact matches. Within a bucket, equal contentHash (or equal value) is an unambiguous Move with similarity: 1.0. A renamed file carries its path in the label, so its contentHash differs on both sides even when the content is byte-identical. The value comparison catches that case.
Jaccard similarity. Remaining candidates are scored by token-level Jaccard similarity over the flattened node text. The best pair above the threshold becomes a Move. A score below 1.0 sets modified: true.

Same-file pairs are skipped throughout. The core already handles intra-file moves.

Usage

import { correlate } from "@ossl-dev/differens-correlate";
import type { FileChanges } from "@ossl-dev/differens-correlate";

// a.ts lost formatPrice; b.ts gained it
const fileChanges: FileChanges[] = [
  { filePath: "src/a.ts", actions: [deletePrice, deleteHelpers] },
  { filePath: "src/b.ts", actions: [insertPrice, insertCart] },
];

const { moves } = correlate(fileChanges);

for (const m of moves) {
  console.log(m.node.label, m.fromFile, "->", m.toFile, m.modified, m.similarity);
}
// formatPrice src/a.ts -> src/b.ts false 1

  → function `formatPrice` from src/a.ts to src/b.ts
  → renamed and edited file src/old/utils.ts to src/new/utils.ts

A kind: "file" match on both sides is a rename, not a move. The CLI reports it as renamed file <from> to <to> (or renamed and edited when modified is set).

​@ossl-dev/differens-correlate

​Exports

​correlate

​The three-stage algorithm

​Usage

@ossl-dev/differens-correlate

Exports

correlate

The three-stage algorithm

Usage