如何在 typescript-node 项目中配置 jest-mongodb(@shelf/jest-mongodb)？

Question

I am working on integration testing, So getting a data from database makes testcase execution slower. Tried with jest-mongodb to set up a temp db. but could not find a proper documentation for setting up jest-mongodb in typescript-nodejs project. please help me to overcome this issue.

test.ts(db configuration file based on this test suites connect to db)

export default {    
    jwtPrivateKey: 'secretkey',
    // Testing Database configuration
    MongoDB: {
        dbConfig: {
            user: 'user name',
            host: 'some host',
            port: 'some port',
            authMechanism: 'some mechanism',
            authSource: 'access level',
            dbName: 'database name',
            metadata: 'initializer'
        }
    }
};

Answer 1

Create the file: typings/global.d.ts :

declare namespace NodeJS {
  export interface Global {
    __MONGO_URI__: string;
  }
}

Then, in your tsconfig.json :

{
  "compilerOptions": { ... },
  "include": ["./src/**/*", "./typings/*"]
}

Answer 2

One way to have this setup is as follows:

Configure Jest with TypeScript via Babel:

yarn add --dev babel-jest @babel/core @babel/preset-env @babel/preset-typescript

Then in your babel config you would have:

// babel.config.js
 module.exports = {
  presets: [
    ["@babel/preset-env", { targets: { node: "current" } }],
    "@babel/preset-typescript"
  ]
};

You can find the docs here Jest TypeScript support via Babel

And finally add @shelf/jest-mongodb to your jest.config.js

// jest.config.js
module.exports = {
  preset: "@shelf/jest-mongodb",
  verbose: true
};

Now you're good to go. In your test file, you'll have access to the test db URL, through:

process.env.MONGO_URL

Or

const globalAny: any = global;
globalAny.__MONGO_URI__

Answer 3

It looks like @shelf/jest-mongodb has removed the exposed global variables and has replaced them with a single environment variable instead. Conveniently this works around the need to declare global typings.

From https://github.com/shelfio/jest-mongodb#readme :

const {MongoClient} = require('mongodb');

describe('insert', () => {
  let connection;
  let db;

  beforeAll(async () => {
    connection = await MongoClient.connect(process.env.MONGO_URL, { // <= MONGO_URL env var set
      useNewUrlParser: true,
      useUnifiedTopology: true
    });
    db = await connection.db(); // <= env var (presumably) includes the db so no longer need to pass this
  });

  afterAll(async () => {
    await connection.close();
  });
});

There is therefore no need to modify your tsconfig.json config to support this.

Answer 4

Jest MongoDB provides all required configuration to run your tests using MongoDB. Described Here

First you need to install @shelf/jest-mongodb,

yarn add @shelf/jest-mongodb --dev

then Specify preset in your Jest configuration:

{
  "preset": "@shelf/jest-mongodb"
}

Then start Writing your tests. like :

const {MongoClient} = require('mongodb');

describe('insert', () => {
  let connection;
  let db;

  beforeAll(async () => {
    connection = await MongoClient.connect(global.__MONGO_URI__, {
      useNewUrlParser: true,
    });
    db = await connection.db(global.__MONGO_DB_NAME__);
  });

  afterAll(async () => {
    await connection.close();
    await db.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);
  });
});

There's no need to load any dependencies. See Jest-MongoBD Documentation on GitHub.

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