The smallest dependency injection framework for Node.js.

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:

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

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)

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

MIT