Verified Delta Pipeline

The package can be used as a client runtime, a release-side Node tool, or both. The shared manifest and bundle schema connects patch generation, CDN selection, and verified restore without owning transport or private signing keys.

Node CLI

Install the package in a release workspace or run it through npx:

npx react-native-bs-diff-patch diff old.bin new.bin -o update.patch
npx react-native-bs-diff-patch inspect update.patch --json
npx react-native-bs-diff-patch verify old.bin update.patch new.bin
npx react-native-bs-diff-patch manifest \
  old.bin update.patch new.bin -o patch-manifest.json

The CLI refuses to overwrite existing output files. Node runs the same WebAssembly core shipped for Web and mounts host paths through NODEFS, avoiding an additional full-file copy in JavaScript. Diff generation still indexes complete inputs inside the C/WASM core; patch application and verification use the bounded streaming file path.

Verified patch manifest

createPatchManifest() and validatePatchManifest() are available from the environment-neutral toolkit entry:

import {
  canonicalJson,
  createPatchManifest,
  signingPayload,
} from 'react-native-bs-diff-patch/toolkit';

const manifest = createPatchManifest({
  baseline: { bytes: 1000, sha256: baselineSha256 },
  patch: { bytes: 120, sha256: patchSha256, url: 'update.patch' },
  target: { bytes: 1100, sha256: targetSha256, url: 'app.bin' },
});

const bytesToSign = new TextEncoder().encode(signingPayload(manifest));
const canonical = canonicalJson(manifest);

The library canonicalizes JSON, validates SHA-256 descriptors, and carries detached-signature metadata. It never loads, stores, or manages a private key. Authenticate the canonical manifest through the signing system already used by your release pipeline.

Verified restore in Node

The Node entry validates the baseline and patch before applying, then validates the restored target before keeping it:

import {
  createFilePatchManifest,
  restoreVerified,
} from 'react-native-bs-diff-patch/node';

const manifest = await createFilePatchManifest(
  'old.bin',
  'update.patch',
  'new.bin'
);

await restoreVerified('old.bin', 'update.patch', 'restored.bin', manifest);

A baseline, patch, or target mismatch rejects with a verification error and does not leave the requested output behind.

Multi-baseline bundle

Generate one target release from every regular file in a baseline directory:

npx react-native-bs-diff-patch bundle \
  --from releases/ \
  --to dist/app.bin \
  --out dist/update-bundle \
  --max-ratio 0.85 \
  --release-id v1.5.0

The output contains:

• the full target fallback;
• one ENDSLEY/BSDIFF43 patch for each cost-effective baseline;
• bundle-manifest.json for humans and CDNs;
• bundle-manifest.canonical.json for signing;
• a decision report showing patch or full-file selection.

At runtime, selectPatch() matches the trusted baseline SHA-256 and applies optional patch-byte or patch-ratio budgets. A missing baseline or an uneconomical patch selects the full artifact explicitly.

GitHub Action

The repository includes a dependency-free action for one baseline:

- uses: JimmyDaddy/react-native-bs-diff-patch@v0.5.0
  id: delta
  with:
    old-file: releases/v1.bin
    new-file: dist/app.bin
    patch-file: dist/update.patch
    manifest-file: dist/patch-manifest.json
    max-patch-ratio: '0.85'

- run: echo "strategy=${{ steps.delta.outputs.strategy }}"

Use the CLI bundle command when the release needs several baselines. The action exposes patch size, target size, ratio, savings, and the selected patch or full strategy as outputs.

BSDIFF40 migration

The runtime continues to accept only ENDSLEY/BSDIFF43. Existing BSDIFF40 files can be converted offline without the baseline file:

npx react-native-bs-diff-patch convert legacy.patch -o compatible.patch
npx react-native-bs-diff-patch inspect compatible.patch

Conversion validates the three BSDIFF40 compressed blocks, rewrites them into the interleaved BSDIFF43 stream, and refuses malformed or existing outputs. Verify the converted patch against its known baseline and target before publishing it.

Browser Release Planner

The Release Planner generates a multi-baseline matrix and the same bundle manifest entirely in the browser. It is intended for evaluation and debugging; use the CLI to reproduce production artifacts in CI. Files selected in the planner are not uploaded.