Jest preset to run MongoDB memory server
$ yarn add @shelf/jest-mongodb --dev Make sure mongodb is installed in the project as well, as it's required as a peer dependency.
module.exports = { preset: '@shelf/jest-mongodb', };If you have a custom jest.config.js make sure you remove testEnvironment property, otherwise it will conflict with the preset.
module.exports = { mongodbMemoryServerOptions: { binary: { version: '4.0.3', skipMD5: true, }, autoStart: false, instance: {}, }, };To use the same database for all tests pass the config like this:
module.exports = { mongodbMemoryServerOptions: { binary: { version: '4.0.3', skipMD5: true, }, instance: { dbName: 'jest', }, autoStart: false, }, };To use separate database for each jest worker pass the useSharedDBForAllJestWorkers: false (doesn't create process.env variable when using this option):
module.exports = { mongodbMemoryServerOptions: { binary: { skipMD5: true, }, autoStart: false, instance: {}, }, useSharedDBForAllJestWorkers: false, };To use dynamic database name you must pass empty object for instance field:
module.exports = { mongodbMemoryServerOptions: { binary: { version: '4.0.3', skipMD5: true, }, instance: {}, autoStart: false, }, };To use another uri environment variable name you must set mongoURLEnvName field:
module.exports = { mongodbMemoryServerOptions: { binary: { version: '4.0.3', skipMD5: true, }, instance: {}, autoStart: false, }, mongoURLEnvName: 'MONGODB_URI', };To use mongo as a replica set you must add the replSet config object and set count and storageEngine fields:
module.exports = { mongodbMemoryServerOptions: { binary: { skipMD5: true, }, autoStart: false, instance: {}, replSet: { count: 3, storageEngine: 'wiredTiger', }, }, };Library sets the process.env.MONGO_URL for your convenience, but using of global.__MONGO_URI__ is preferable as it works with useSharedDBForAllJestWorkers: false
const {MongoClient} = require('mongodb'); describe('insert', () => { let connection; let db; beforeAll(async () => { connection = await MongoClient.connect(global.__MONGO_URI__, { useNewUrlParser: true, useUnifiedTopology: true, }); db = await connection.db(); }); afterAll(async () => { await connection.close(); }); });it('should insert a doc into collection', async () => { const users = db.collection('users'); const mockUser = {_id: 'some-user-id', name: 'John'}; await users.insertOne(mockUser); const insertedUser = await users.findOne({_id: 'some-user-id'}); expect(insertedUser).toEqual(mockUser); });Cache MongoDB binary in CI by putting this folder to the list of cached paths: ./node_modules/.cache/mongodb-memory-server/mongodb-binaries
You can enable debug logs by setting environment variable DEBUG=jest-mongodb:*
beforeEach(async () => { await db.collection('COLLECTION_NAME').deleteMany({}); });See this issue for discussion
This package creates the file globalConfig.json in the project root, when using jest --watch flag, changes to globalConfig.json can cause an infinite loop
In order to avoid this unwanted behaviour, add globalConfig to ignored files in watch mode in the Jest configuation
// jest.config.js module.exports = { watchPathIgnorePatterns: ['globalConfig'], };$ git checkout master $ pnpm version $ pnpm publish $ git push origin master --tagsMIT © Shelf