New Rule: Empty Args

[Snugug]

With Sass, if a function or mixin doesn't have any arguments, the parenthesis can be left off of the definition and, in the case of mixins, the invocation as well

[bgriffith]

Started to look into this one. Experience is slightly different. Parenthesis can be left off of the definition of mixins but not functions. When I try I get a Sass error;
@function baz ": expected "(", was "{"

While I can drop the parenthesis off both the invocation of functions and mixins.

// Causes an error
@function baz {
  @return 'baz';
}

// Is ok
.baz {
  content: baz;
}

// Is ok
@mixin qux {
  content: 'baz';
}

// Is ok
.qux {
  @include qux;
}

[Snugug]

Check out this Sass Meister:
http://sassmeister.com/gist/17649e207a82c4efb946

The function isn't being invoked if it doesn't include (), you just happen to have named the function and its return the same, making it appear to be OK.

There is, however, a discrepancy between Libsass and Ruby Sass as to whether a function can be defined w/o (). Libsass allows it, Ruby Sass does not.

[bgriffith]

Haha oh dear. Amateur mistake! Libsass are working towards parity with Ruby Sass so do you agree that this rule should be mixin only?

[Snugug]

I trusted you man! I trusted you! 😝

[bgriffith]

Hahaha 😁 - Thoughts on above?

[Snugug]

Yah, only for mixins makes sense to me