Rule for braces when used semicolon free style

[kof]

I personally prefer semicolon free javascript. But there are some pitfalls when braces are in place. We can add a lint rule which will ensure not to have those runtime errors.

Is eslint project itself interested in adding such a rule?
Is somebody else is interested in a separate project which can implement this rule or maybe it exists already and I missed it?

[eslintbot]

Thanks for the issue! If you're reporting a bug, please be sure to include:

1. The version of ESLint you are using (run eslint -v)
2. What you did (the source code and ESLint configuration)
3. The actual ESLint output complete with numbers
4. What you expected to happen instead

Requesting a new rule? Please see Proposing a New Rule for instructions.

[kof]

Also linting this possible runtime errors would end the debates about semicolons hopefully as there will be no risk any more.

[kof]

cc @feross

[mr-mig]

I know about 2 pitfalls with omitting semicolons.

Return statements

function add(a, b){
  return 
    a + b
}

() or [] at the beginning of the line

function fnA() {}

(function myModule(){

})()

and

function highOrderFunction() {}

[fn1, fn2, fn3].map(highOrderFunction)

[ilyavolodin]

@kof Could you provide more details about what you are looking for? We have guidelines for new rule proposal here

[kof]

When does this rule warn? Please describe and show example code:

When options semi is defined as: "semi": [2, "never"] and following code was detected (just an example, there are more):

(function a() {})
(function(){
})

Is this rule preventing an error or is it stylistic?

ERROR

Why is this rule a candidate for inclusion instead of creating a custom rule?

because eslint has already a rule for semicolon free style, this options will just ensure not having side effects from using the other rule with provided options.

Are you willing to create the rule yourself?

it depends on how hard it is.

[nzakas]

Have you looked at: http://eslint.org/docs/rules/no-unexpected-multiline

[kof]

Oh this is exactly what I was looking for, I think we should link this rule within related rules of "semi" rule ...

Also worth mentioning it is off by default.

[michaelficarra]

@kof where would you need a semicolon in that program?

[kof]

@michaelficarra changed it a bit to produce the effect I wanted to point out, its all fine we have a rule for this, just documentation issue.

[michaelficarra]

Now it makes a lot more sense.

[nzakas]

@kof all rules are off by default, so there's little value in restating that in documentation.

Feel free to submit a PR for the other doc change.

[kof]

thanks @ilyavolodin you was a bit faster)