Support separate requires in one-var

ESLint Version: 2.10.1

Problem:

A common request (e.g, #3091, #1232) is for the one-var rule to properly function in tandem with no-mixed-requires. I agree with this opinion, as the two methods are part of the core set of rules provided with ESLint and should properly support each other. I also believe there is a way to support this without introducing a dependency between the two rules.

Recommended Solution:

I believe this should not be a plugin, as both commands are part of the core library and cause conflict with each other. A better solution would be to add an optional parameter separate-requires to one-var that allows for require keywords to be separated into a single block, while assignments are in another block (similar to the intent of the two-var plugin).

For example:

"one-var": ["error", {
    "separate-requires": true,  // (New) Enforces requires to be separate from declarations
    "var": "never",
    "let": "never",
    "const": "never"
}]

This will allow ESLint to properly support it’s built-in plugins without changing the default functionality of the one-var rule. With the above configuration:

This code would result in an error:

const gulp = require('gulp'),
      myModule = require('./some/module'),
      myVar1 = 1,
      myVar2 = 2;

This code would be valid:

const gulp = require('gulp'),
      myModule = require('./some/module');

const myVar = 1,
      myVar = 2;

[mikeletscher]

@onurtemizkan Was like 2/3 of the way done, but don’t let me stop you!

[mikeletscher]

I will take a look into getting a PR up for this sometime this week/weekend.