Feature request: UI that does not use the `this` keyword

Given a world such as:

require('cucumber').defineSupportCode( ({setWorldConstructor:world}) => {
    world(class { 
      constructor(p) { ... }
      foo(bar) { return new Promise(.... ) }
    })
})

I want to be able to write:

  When(/^I do the foo with (.*)$/i, (ctx, bar) => ctx.foo(bar) );

instead of

  When(/^I do the foo with (.*)$/i, function(bar) {
      return this.foo(bar)
  });

This will also rid me from monkeying the .bind(this) on all async operations, or if you prefer - rid of monkeying with var that = this.

One more benefit (IMHO)- it will help people get off inheritance tree for worlds and orient them better towards the better powers of JS

[charlierudolph]

Okay. As not everyone is a functional programmer though and to prevent the introduction of a breaking change, what do you guys think of making an option which makes the world be passed as the first parameter?

defineSupportCode(({setWorldInjectionStrategy}) => {
  setWorldInjectionStrategy('this') // default
  setWorldInjectionStrategy('argument') // makes world be the first argument to steps and hooks 
})

[armandabric]

I totally agree with the idea to inject the world/context has a parameter of the step. Starting by this project, all the JS ecosystem is moving to fully embrace the new functionalities allowed by ES6 and that’s a good things ❤️

If you look on other tools like Express or Koa, they set the current request context as the this AND as first parameter of the middleware (it is the equivalent of cucumber step). This solution allow traditional use of function and the use of ES6 arrow function. Another advantage of the context in as the first parameter is that

For the solution proposed by @charlierudolph, I do not think this could works on a long run: this will split the community in two. All cucumber examples will not be working in all installations and the docs will be duplicated in two. Not fancy.

I’m not sure about the breaking change worries, the v2 is the perfect time to introduce this kind of change. Waiting will force to make/wait for another major.