Starting Lines With Semicolons (ES6)

[mattdesl]

Note: This isn't a question about whether to use ASI or not (already discussed #78).

@maxogden

We no longer recommend starting lines with semicolons. It's hacky. Start lines with void, var, const or something that makes more sense.

Can you expand on this a bit more? To me void is confusing and code-smell-ish. I don't really see anything wrong with enforcing a preceding semicolon for [ and ( and disallowing lines starting with other operators (like regexes and template strings).

Preceding semicolon:

let [ x, y ] = [ 8, 2 ]
;[ x, y ] = [ y, x ]

Void: (does this even work??)

let [ x, y ] = [ 8, 2 ]
void [ x, y ] = [ y, x ]

Avoiding it completely:

let [ x, y ] = [ 8, 2 ]
let t = x
x = y
y = t

Aside from swapping variables, it can also be useful to write code like this:

//translate Z and project into 2D
let [ x, y, z ] = position()
z += translation
;[ x, y ] = project([ x, y, z ])

drawPoint(x, y)

[maxogden]

My opinion is if you have ;[ or ;( it should not cause a standard error. I just didn't think it was the best thing to have as the first code example in the readme.

[mattdesl]

Ah, the wording led me to believe the tool would never allow it. Maybe listing it as a bullet point below "no semicolons" would be better, like:

"Any lines starting with [ or ( require a preceding semicolon; but using shorthand patterns is discouraged"

It could link to a code example showing the ;[ approach next to the preferred alternative (with var or some assignment). And maybe a note about ES6 edge cases.

[maxogden]

@mattdesl not a bad idea, I think we might as well just change that whole line to link to a separate markdown file with more detail rather than try to explain complex stuff in the bullet list

[feross]

Let's add more detailed explanations of these edge cases on the wiki: https://github.com/feross/standard/wiki

I'm going to close this now. Thanks for bringing this up, @mattdesl!

[mattdesl]

@feross
Some edits if you want to review:
https://gist.github.com/mattdesl/4fb2e1d2c0b5a0b8048a#asi

You could pull the wiki into git for proper commits/PRs/etc. I tend to do that on my own projects since the wikis are a bit lacklusre.

[feross]

Thanks @mattdesl. Added a RULES.md file and removed the wiki.