Can You Find the Bug in This Code? • Hacker News Board

Re: Can You Find the Bug in This Code?

#11

Post by Someone1234 » Mon, Feb 11, 2019, 4:59 PM UTC

gammateam wrote: post #3

I feel good that my first thought of fixing it would have created the solution. There were obvious errors in my mind that I would fix without knowing the whole dissertation on why it happened. So maybe if the question was, "Can you repair this code", I would excel.

Ditto. I didn't know it was a missing semicolon, but the code smells bad regardless and my solution also would have solved it another way (just by improving code readability/clarity).

It is likely one of these "trust your gut" situations.

Re: Can You Find the Bug in This Code?

#12

Post by adrianhel » Mon, Feb 11, 2019, 5:00 PM UTC

scandox wrote: post #7

The real bug is the failure to use semi-colons. I literally cannot comprehend the non-use of semi-colons in JS.

If so, the failure lies with the spec. (personally, I like ASI)

Re: Can You Find the Bug in This Code?

#13

Post by ezekg » Mon, Feb 11, 2019, 5:02 PM UTC

adrianhel wrote: post #4

Always prepend ( and [ with ; I also prefer void function () {} for this. Void the result of this function expression which I immediately invoke.

I'm not sure always prepending those with ";", but definitely when needed, sure. But most of the time you can simply refactor the code a little bit and improve readability with the addition of a single variable.

Re: Can You Find the Bug in This Code?

#14

Post by tniemi » Mon, Feb 11, 2019, 5:02 PM UTC

Don't use "gonad" javascript, or just use semicolons.

With dangling balls: `(function(){})()`

No dangling balls: `(function(){}())`

https://gist.github.com/newswim/4668aef8a1f1bc0dabe8

Re: Can You Find the Bug in This Code?

#15

Post by Etheryte » Mon, Feb 11, 2019, 5:03 PM UTC

An even more common use-case that fails without semicolons by T.J. Crowder (2015): http://blog.niftysnippets.org/2015/09/automatic-semicolon-in...

There are a number of cases where not having semicolons has its downsides, I'm yet to see a single case of an upside.

Re: Can You Find the Bug in This Code?

#16

Post by jbredeche » Mon, Feb 11, 2019, 5:04 PM UTC

Reminds me of https://github.com/twbs/bootstrap/issues/3057

Re: Can You Find the Bug in This Code?

#17

Post by ezekg » Mon, Feb 11, 2019, 5:04 PM UTC

ezekg wrote: post #10

I refuse to use semi-colons in TS/JS, unless that conflicts with existing code standards. I feel like it's as if I'm using semi-colons in Go. This can easily be avoided by writing clearer code.

Relevant: https://standardjs.com/rules.html#semicolons (hint: no semi-colons!)

Re: Can You Find the Bug in This Code?

#18

Post by jyriand » Mon, Feb 11, 2019, 5:05 PM UTC

“Must be a semicolon issue,” was my first thought, without actually knowing why.

Re: Can You Find the Bug in This Code?

#19

Post by Klathmon » Mon, Feb 11, 2019, 5:05 PM UTC

ezekg wrote: post #13

adrianhel wrote: post #4

Always prepend ( and [ with ; I also prefer void function () {} for this. Void the result of this function expression which I immediately invoke.

I'm not sure always prepending those with ";", but definitely when needed, sure. But most of the time you can simply refactor the code a little bit and improve readability with the addition of a single variable.

More correctly it's:

Always prepend any line that begins with ( and [ and ` with ;

Re: Can You Find the Bug in This Code?

#20

Post by adrianhel » Mon, Feb 11, 2019, 5:06 PM UTC

ezekg wrote: post #13

adrianhel wrote: post #4

Always prepend ( and [ with ; I also prefer void function () {} for this. Void the result of this function expression which I immediately invoke.

I'm not sure always prepending those with ";", but definitely when needed, sure. But most of the time you can simply refactor the code a little bit and improve readability with the addition of a single variable.

Always for ( and [ when they start a statement.

It really is that simple.