Singular NPM | npm.io

Singular is dependency manager for modular applications. Its' modules are CommonJS-alike classes.

Singular can load modules in runtime for example WASM modules or mock any module in test environment.

Installation

Install from NPM:
```
npm i singular
```

Inject using unpkg.com:

<script src="https://unpkg.com/singular@3/dist/singular.js"></script>
<script src="https://unpkg.com/singular@3/dist/singular.min.js"></script>

⚠️ Remember about security! Add subresource integrity (SRI) checksum from checksum.txt.

Example

Singular is made for simple configuration and initialization:

import Singular from 'singular'

const singular = new Singular({
  modules: {
    mongo: new MongoModule(),
    sqlite: new SqliteModule(),
    user: new UserModule({
      // User module layout requires mongo `db` which is `mongo` in current app
      db: 'mongo',
    }),
    transactions: new TransactionsModule({
      // Transactions module layout requires sqlite `db` which is `sqlite`
      // in current app
      db: 'sqlite',
    }),
  },
})

Usage and API

Instantiate and configure new singular instance.

import Singular from 'singular'

const config = {
  logger: {
    level: 'INFO',
  },
  mongo: {
    connect: 'mongodb://...'
  },
  sql: {
    type: 'sqlite',
    dbPath: './db.sqlite',
  },
}

const singular = new Singular({
  config,
})

Inject dependencies with start method.

// Inject logger and log something
singular.start()
.then(({ mongo, sqlite }) => {

})

Module Example

Define module using ES2019 syntax:

class GreetingModule extends Singular.Module {
  deps = {
    // Logger is required
    logger: true,
  }

  defaults = {
    name: 'World'
  }

  async start(config, scope, exports) {
    const {logger} = scope

    exports.greet = function(name) {
      logger.log('Hello, %s!', name || config.name)
    }

    // Or

    return {
      greet(name) {
        logger.log('Hello, %s!', name || config.name)
      },
    }
  }

  async stop() {
    // ... Do something to shutdown module gracefully ...
  }
}