Service Registry

npm install --save https://github.com/bigbadweb/service-registry.git

services/index.js

const services = require('@bigbadweb/service-registry');

// bootstrap services

const DatabaseService = require('@bigbadweb/mysql-database-wrapper');
services.register('db', new DatabaseService(process.env.DATABASE_URL));

const myService = () => {
    someFunc: () => {
        return "something";
    }
}

services.register('myservice', myService);

module.exports = services;
module.exports.db = services.get('db');
module.exports.myservice = services.get('myservice');

someroute.js

const services = require('./services/'); // loads index.js, above by default

router.get('/something', (req, res, next) => {
    let thing = services.myservice.someFunc();
    next();
});

router.get('/a-db-query', async (req, res, next) => {

    let thing = await services.db.query('SELECT * FROM table WHERE id = ? ', [99]).catch(err => {
        return next(err);
    });
    res.render('somepage', {  thing: thing});

});

Circular dependencies - injectServices

If your services depend upon each other, but not during instantiation, use the injectServices mechanism after registering your services to inject references to other services in the this. scope of the service. e.g. the following makes this.db available to the myservice Service. This is instead of using services.get('db') inside the service.

const services = require('@bigbadweb/service-registry');

// bootstrap services

const DatabaseService = require('@bigbadweb/mysql-database-wrapper');
services.register('db', new DatabaseService(process.env.DATABASE_URL));

const myService = () => {
    someFunc: () => {
        return "something";
    }
}

services.register('myservice', myService);

const myService = () => {
    someFunc: async () => {

        const data = await this.db.query('SELECT * FROM TABLE')
        return "something";
    }
}

services.register('myservice', myService);

// inject services by name of service.
services.injectServices('myservice', ['db]);

module.exports = services;
module.exports.db = services.get('db');
module.exports.myservice = services.get('myservice');