schema-migrate-lite

Versioning and migration utility for JSON-driven configs — define stepwise migrations and run a config forward to the latest (or any target) version. Zero dependencies.

Install

npm install schema-migrate-lite

Quick start

import { MigrationRunner } from 'schema-migrate-lite';

const runner = new MigrationRunner([
  { from: 1, to: 2, migrate: (c) => ({ ...c, fullName: c.name, name: undefined }) },
  { from: 2, to: 3, migrate: (c) => ({ ...c, theme: 'default' }) },
]);

const upgraded = runner.migrate(storedConfig); // walks 1 -> 2 -> 3 automatically

Why stepwise migrations instead of one big transform

A single "convert any old version to the latest" function grows unreadable fast and has to be rewritten every time the schema changes again. Stepwise migrations (from -> to, one small transform each) compose: adding version 4 means adding one new migration, not touching the accumulated logic for 1→2→3. MigrationRunner just walks the chain from the config's current version to the target, applying each step in order.

API

• new MigrationRunner(migrations) — migrations: { from, to, migrate }[]
• .migrate(config, options?) — walks forward to options.targetVersion (default: latest registered to)
• .latestVersion() — highest to among registered migrations

Throws if no migration exists for the current version, or if the config's version is already newer than the target.

License

MIT