Indent when as deep as case

[unixmonkey]

https://github.com/getfretless/ruby#indentation

Here's one I slightly disagree with:

I personally would like to see:

kind = case year
  when 1850..1889 then 'Blues'
  when 1890..1909 then 'Ragtime'
  when 1910..1929 then 'New Orleans Jazz'
  when 1930..1939 then 'Swing'
  when 1940..1950 then 'Bebop'
  else 'Jazz'
end

with the when's and else indented 2-spaces over either of these (the AirBnB recommendations):

case
when song.name == 'Misty'
  puts 'Not again!'
when song.duration > 120
  puts 'Too long!'
when Time.now.hour > 21
  puts "It's too late"
else
  song.play
end

kind = case year
       when 1850..1889 then 'Blues'
       when 1890..1909 then 'Ragtime'
       when 1910..1929 then 'New Orleans Jazz'
       when 1930..1939 then 'Swing'
       when 1940..1950 then 'Bebop'
       else 'Jazz'
       end

I think I understand why AirBnB and others don't like this, though.
Case doesn't take a block, and if you indent your whens and else, the else doesn't line up with end.

kind = case year
  when 1850..1889
    'Blues'
  when 1890..1909
    'Ragtime'
  else
    'Jazz'
end

But I would even prefer that.

Or even this:

case something
  when 1850..1889 then 'Blues'
  when 1890..1909 then 'Ragtime'
else
  'Jazz'
end

I think of the indentation as being the "method body", as that's where the meat is, and it is more like an other control structures (like if), so it makes sense to me, and is more aesthetically pleasing to have it indented (IMO).

[mileszs]

I think of whens as elsifs, thus

case
when song.name == 'Misty'
  puts 'Not again!'
when song.duration > 120
  puts 'Too long!'
when Time.now.hour > 21
  puts "It's too late"
else
  song.play
end

looks good to me.

I really dislike the hanging indent thing, though:

kind = case year
       when 1850..1889 then 'Blues'
       when 1890..1909 then 'Ragtime'
       when 1910..1929 then 'New Orleans Jazz'
       when 1930..1939 then 'Swing'
       when 1940..1950 then 'Bebop'
       else 'Jazz'
       end

In general, I dislike assigning the result of a conditional to a method. I think I'm an outlier in the Ruby community there, though. Still, I'd take your

kind = case year
  when 1850..1889
    'Blues'
  when 1890..1909
    'Ragtime'
  else
    'Jazz'
end

over the hanging indent any day.

[dstrus]

I'm actually with AirBnB on this one. Like @mileszs, I'm not nuts about performing assignments this way anyway. But I get twitchy when case doesn't line up with when and else.

[dstrus]

else is just a special when (the default), so aligning it with case but not when doesn't feel right to me.

[mileszs]

This is good discussion.

@unixmonkey How do you feel about JS switch statements, typically written:

switch(today){
case 1:
    window.location="monday.htm"
    break
case 2:
    window.location="tuesday.htm"
    break
case 3:
    window.location="wednesday.htm"
    break
case 4:
    window.location="thursday.htm"
    break
case 5:
    window.location="friday.htm"
    break
case 6:
    window.location="saturday.htm"
    break
case 0:
    window.location="sunday.htm"
    break
}

Do brackets make that discussion different?

[unixmonkey]

No. In fact, in my experience, I've seen JS switch statements more often indented like so:

switch(today){
  case 1:
    window.location="monday.htm";
    break;
  case 2:
    window.location="tuesday.htm";
    break;
  case 3:
    window.location="wednesday.htm";
    break;
  default:
    window.location='/';
}

Which may have influenced my thinking of "when" as innner-block stuff, and not as a special "else".

[mileszs]

Ah, interesting. Crockford prefers less indentation, but it sounds like the JSHint community is torn on the subject.