Cop idea: redundant if-else statement

[ydakuka]

Is your feature request related to a problem? Please describe.

I have the code samples:

a1)

my_field =
  if condition?
    my_field
  else
    Time.now.utc
  end

my_field

a2)

my_field = condition? ? my_field : Time.now.utc

my_field

b1)

my_field =
  if condition?
    Time.now.utc
  else
    my_field
  end

my_field

b2)

my_field = condition? ? Time.now.utc : my_field

my_field

Rubocop has not detected any offenses.

ydakuka@yauhenid:~/Work/project$ bin/rails_docker rubocop example.rb
Inspecting 1 file
.

1 file inspected, no offenses detected

Describe the solution you'd like

I expected to have the following code samples:

a)

unless condition?
  my_field = Time.now.utc
end

my_field

b)

if condition?
  my_field = Time.now.utc
end

my_field

[l3x4]

Maybe one-liner?

my_field = Time.now.utc if(unless) condition?

If the last my_field in your examples is an implicit return value, it can be also done like this:

def some_meth(my_field)
  return Time.now.utc if(unless) condition

  my_field
end

[vlad-pisanov]

I think that's what Style/RedundantSelfAssignmentBranch is for.

For example, this:

foo = cond? ? foo : bar

gets flagged with Style/RedundantSelfAssignmentBranch: Remove the self-assignment branch and is autocorrected to:

foo = bar unless cond?

However, if the branch is an expression, the cop doesn't detect it 🤔

foo = cond? ? foo : Time.now # no offense