instill

instill

The littlest dependency injection framework for Node.js.

API

Usage

const inject = require('instill')

inject(exports, {
  fs: require('fs')
})

exports.readAFile = function (...args) {
  this.modules.fs.readFile(...args)
}

You then have essentially two options:

• use: This will change a dependency in the current module instance. Useful for injecting configuration-based dependencies. This affect all other parts of the code using this module.

• with: Creates a copy of the current module. Useful for testing.

Example:

describe('testing', function () {
  require('logger').use('winston', ...)

  it('test readAFile', function (done) {
    require('myModule').with({
      fs: require('mock-fs').fs({
        myFile: 'some content'
      })
    }, function (myModuleCopy) {
      myModuleCopy.readAFile('myFile', done)
    })
  })
})

This will:

• Mock winston in the logger. All other modules using the logger module will be affected.
• Get a copy of myModule, and test it.

Instanciating objects

The only drawback of this library is that you will need to change how objects get instanciated. If you do not like it, well... I understand. It's OK.

First, you will need to register your classes, like so:

inject(exports, {
  fs: require('fs')
}, {
  SomeClass,
  SomeOtherClass
})

Then, to create an instance of registered classes:

  const someObject = myModule.instanciate('SomeClass', 1, 2, 3)

TODO

• Test suite, linting, etc.
• Maybe support AOP?

License

MIT