Check for parentheses when within parameter list

[agrimm]

The following code doesn't create an offense:

# Does fooing
class Foo
  def needs_parentheses
    foo(bar 1, 2)
  end
end

Should it do so? I think it's too easy to mistake it as saying foo(bar, 1, 2).

[alexdowad]

I think whatever rules as regards parenthesizing method calls are applied elsewhere, should also be applied here in just the same way. It doesn't deserve a special case.

[bbatsov]

There are very few rules that are enforced automatically about parens. Mostly because it's really hard to determine if something is a DSL method (which generally are invoked without parens).

I think @agrimm is right that the code he presents in the example is a bit unclear.

[jonas054]

I think a new cop for this special case would be a good idea. A method call without parentheses that's an argument in another method call is a weird thing.

[alexdowad]

I have a cop for this, waiting for my outstanding PR to be merged before I open another one.

[alexdowad]

The new cop flags this:

 expect(slice.any? { |l| l.include? cop.cop_name }).to be_truthy

...because of the #include? call. Do you like this? Or should this be exempt, perhaps because it is inside a block?

[BenMorganIO]

Hmmm I'm thinking this was a bit too hastey. I got some code that looks like:

foo(bar 'hello')

I consider that quite OK since you can tell there's an inside function. I'm thinking that this cop should only be on if the arity is greater than 1.

[alexdowad]

I consider that quite OK since you can tell there's an inside function. I'm thinking that this cop should only be on if the arity is greater than 1.

Rather than adding more and more rules about when parens are required, I suggest we keep this cop simple. People who don't like the simple rule can disable the cop.