FavorUnlessOverNegatedIf triggered when using elsifs

[jurriaan]

Here's an example:

test = 'String'

a = if test.is_a?(String)
  3
elsif test.is_a?(Array)
  2
elsif !test.nil?
  1
end

p a

which gives the following output:

Offences:

test.rb:7:1: C: FavorUnlessOverNegatedIf: Favor unless (or control flow or) over if for negative conditions.
elsif !test.nil?
^^^
test.rb:9:1: W: EndAlignment: end at 9, 0 is not aligned with if at 3, 4
end
^^^

1 file inspected, 2 offences detected

How to fix this? I think it FavorUnlessOverNegatedIf shouldn't trigger in this case.
I also think the EndAlignment shouldn't trigger either.

[markijbema]

Shouldn't elsif be ignored altogether by this cop? There's no elsunless you can use in this case.

[jurriaan]

I think so. The comment in the cop says it ignores if's with else statements. But it doesn't work for elsifs..

[bbatsov]

Internally the parser represents elsif as a nested if, which is probably causing the bug.

[jurriaan]

Thanks! What about the EndAlignment cop?

[bbatsov]

This is intentional - most IDEs/editors align if/else/elsif/end even for assignments, so we've decided to discourage other indentation practices. You'll notice that this indentation style is fine for blocks, though.

[jurriaan]

Your latest change breaks ternary operators:

letme = crash ? :rubocop : ':('

=>

An error occurred while FavorUnlessOverNegatedIf cop was inspecting test.rb.
undefined method `keyword' for #<Parser::Source::Map::Ternary:0x007ff2bfac2948>
.../gems/rubocop-040b17a66d89/lib/rubocop/cop/style/favor_unless_over_negated_if.rb:30:in `on_if'

[bbatsov]

That is no longer my latest change - this is already fixed :-)

[jurriaan]

👍