yammy

library2.1.0jsnpmunverified

Yammy is a MongoDB migration library (v2.1.0) designed for programmatic use as a module, unlike CLI-focused alternatives. It supports multiple databases, backward compatibility with migrate-mongo, and uses transactions by default for data integrity. Requires Node.js >=8.0.0 and MongoDB >=2.6 (or >=4.0/4.2 for transactions). Stable release with TypeScript type definitions included, released under MIT license.

database

npm install yammy

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · YAMMY

yammy

databasejavascriptv2.1.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Migrate

✓ import { Migrate } from 'yammy'

✗ const Migrate = require('yammy')

ESM import for TypeScript/ES modules; CommonJS users can use require but note the named export.

Migration

✓ import type { Migration } from 'yammy'

✗ import { Migration } from 'yammy'

Type-only import for defining migration structure; not a runtime value.

YammyOptions

✓ import type { YammyOptions } from 'yammy'

✗ import { YammyOptions } from 'yammy'

Type-only import for constructor options interface.

Initialize Migrate instance, list pending migrations, and apply them. Includes example migration file with up/down functions.

import { Migrate } from 'yammy'; const migrate = new Migrate( { uri: process.env.MONGO_URI ?? 'mongodb://localhost:27017', options: { useNewUrlParser: true, useUnifiedTopology: true } }, { autoClose: true, dir: './migrations' } ); // List pending migrations migrate.pending() .then((migrations) => { console.log('Pending:', migrations); // Run all pending return migrate.up(); }) .then(() => console.log('Migrations applied successfully')) .catch(err => console.error(err)); export const up = async (db, session) => { await db.collection('mycollection').createIndex({ email: 1 }, { unique: true, session }); }; export const down = async (db, session) => { await db.collection('mycollection').dropIndex('email_1', { session }); }; export const db = 'mydb';

Debug

Known issues

breakingIn version 2.x, the Migrate constructor signature changed. Options object now takes two arguments: dbConfig and globalOptions.

fix

Update constructor to `new Migrate({ uri, options }, { autoClose, dir })`

affects: >=2.0.0

gotchaMigrations using transactions require MongoDB replica set (>=4.0) or sharded cluster (>=4.2). Default migrations will fail if not supported.

fix

Ensure MongoDB is configured for transactions or set `useTransactions: false` in options.

affects: >=1.0.0

gotchaThe migration file must export a `db` string property to specify target database, otherwise migrations will apply to all databases.

fix

Add `exports.db = 'your_database_name';` to each migration file.

affects: >=1.0.0

deprecatedThe CLI usage via `npx yammy` is deprecated in favor of programmatic API. CLI may be removed in future releases.

fix

Use the Migrate class in your application code instead of CLI.

affects: >=2.0.0

Errors

Common errors & fixes

TypeError: Migrate is not a constructor

Improper import/require style: using default import instead of named import.

fix

Use `import { Migrate } from 'yammy'` (ESM) or `const { Migrate } = require('yammy')` (CommonJS).

MongoError: Transaction numbers are only allowed on a replica set member or mongos

Trying to use transactions on a standalone MongoDB instance.

fix

Either switch to a replica set or set `useTransactions: false` in Migrate options.

Cannot find module 'yammy'

Package not installed.

fix

Run `npm install yammy` in your project directory.

Error: No database provided in migration file

Migration file missing `exports.db` property.

fix

Add `exports.db = 'myDatabaseName';` to the migration file.

Upgrade

Version history

2.1.0latest on npm

Audit

Dependencies

mongodbrequiredPeer dependency for database operations; must be installed separately.

Agent activity

29 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/SkeLLLa/yammy ↗

packageyammy ↗

homepagehttps://gitlab.com/m03geek/yammy#README ↗