false offense detected by Style/MixinUsage

[InteNs]

Expected behavior

thing = Class.new do
  attr_accessor :value_text, :value_type
  include IsNameValueType
end

RSpec.describe IsNameValueType do
  subject { thing.new }
  # tests
end

expect Mixin usage to be correct

Actual behavior

Inspecting 4 files
.C..

Offenses:

spec/models/concerns/is_name_value_type_spec.rb:3:3: C: Style/MixinUsage: include is used at the top level. Use inside class or module.
  include IsNameValueType
  ^^^^^^^^^^^^^^^^^^^^^^^

4 files inspected, 1 offense detected

Steps to reproduce the problem

create the test as in the expected behaviour and run rubocop <filename>

RuboCop version

Include the output of rubocop -V. Here's an example:

➔ rubocop -V
0.51.0 (using Parser 2.4.0.0, running on ruby 2.4.1 x86_64-darwin16)

[dreid]

It looks like this cop misreports for any case where the class is the first in some set of siblings.

For example:

class A
  include Mixin
end

class B
  include Mixin
end

Result:

❯ rubocop t.rb
Inspecting 1 file
C

Offenses:

t.rb:2:3: C: include is used at the top level. Use inside class or module.
  include Mixin
  ^^^^^^^^^^^^^

1 file inspected, 1 offense detected

Of note is that only the first class has this error reported.

❯ rubocop -V
0.51.0 (using Parser 2.4.0.0, running on ruby 2.3.4 x86_64-darwin16)

[benhutton]

I'm also getting false positives for this:

RSpec::Matchers.define :do_something do
  include Mixin
end

Again, strangely, only for the first occurrence in a file. I define three matchers in one file, all with the same mixin, and only get flagged for the first one.

.....

It is a bit unclear from the mixin code itself and the PR what the goal of the cop is. Is it really to prevent mixing into Object? Is it to prevent mixing into main? Is it to prevent mixing in outside of a class or module? Let's state very explicitly what the goal is, and then implement against it more narrowly!

[RemyMaucourt]

I have the same problem, and another info.

class A
  include module_A
  include namespace_1::module_B
  include namespace_1::module_C
  include module_D
end

class B
   include module_E
end

Rubocop will raise Style/MixinUsage only for module_A and module_D, not the namespaced ones.

$ rubocop -V
0.51.0 (using Parser 2.4.0.0, running on ruby 2.4.1 x86_64-linux)

[Drenmi]

Indeed. It's a bit unclear what the implementation is trying to do, but it's clear that it's incorrect. 🙂

[ZASMan]

Is there any fix on this? It's still popping up for me.

[pocke]

@ZASMan
Can you try updating rubocop to 0.52.0? It has been fixed in 0.52.0 already.
If you still have any bugs, please open a new issue.