prefer-arrow-callback: allowUnboundThis description may be confusing

[vsemozhetbyt]

http://eslint.org/docs/rules/prefer-arrow-callback#allowunboundthis

I've read this paragraph several times and by comparison with the code example it seems a bit confusing:

1. "When set to false, this option allows the use of this without restriction...": does not the option apply more restrictions for using this?

2. "...checks for dynamically assigned this values...": does "checks" mean "prohibits" or "allows"?

3. "Normally, the rule will flag...": does "Normally" mean "true" or "false" for this option?

The code example is clear, but the description seems to be vague.

[not-an-aardvark]

Thanks for reporting, I agree that the documentation is unclear/misleading here. To answer your questions:

• The default behavior is {allowUnboundThis: true}. With the default behavior, the rule allows function expressions containing this, provided that they are not explicitly bound. This is because these functions would not be directly replaceable with arrow functions.

  foo(function() { this; }) // allowed by default
  foo(function() { this; }.bind(this)) // disallowed

• When allowUnboundThis is set to false, the rule imposes a stricter requirement by disallowing all function expressions containing this, even though those functions are not directly replaceable with arrow functions.

[webdevdaemon]

Hello friends,

Looking to make my first ever PR on this one. Have signed the agreement and will follow the contribution guidelines to the best of my ability. If there is any objection to me taking a crack at this one - please advise.

Thanks for the opportunity,
-Charles

Also if anyone has the time, I am open to any suggestions or advice on the direction I should go in fixing this piece of the docs - but it seems pretty straightforward so I am just gonna go for it. I'll state again however, that any and all input is welcome.

[platinumazure]

@webdevdaemon Thanks for volunteering! We look forward to your PR 😄 I agree this should be pretty straightforward, so I would suggest giving it a try and then we can provide suggestions as needed while reviewing the pull request.

[webdevdaemon]

SWEET. Thx for the rapid reply - I'm on it.

[webdevdaemon]

I just realized that i PR'd 4 commits rather than just one... I'm sure you'll let me know if I need to fix that...

1000 apologies.

PR submitted though!