Style/ParallelAssignment: swap detection for ActiveRecord

[arokettu]

Summary: The Style/ParallelAssignment should ignore self. on the left when detecting variable swap

Actual behavior:

I have a code like

self.width, self.height = self.height, self.width

It says:

C: Redundant self detected.
        self.width, self.height = self.height, self.width
                                  ^^^^^^^^^^^
C: Redundant self detected.
        self.width, self.height = self.height, self.width
                                               ^^^^^^^^^^

That is expected, ok. I fix it

self.width, self.height = height, width

Now I get

C: Do not use parallel assignment.
        self.width, self.height = height, width
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Expected behavior: No Style/ParallelAssignment vioaltions should be found in the line

I guess the cop should treat vars on the left with self. like vars on the right without self.

$ rubocop -V
0.41.1 (using Parser 2.3.1.2, running on ruby 2.3.1 x86_64-linux)

[bbatsov]

Makes sense.