Suggestion: Add notes about returned value of ActiveRecord transaction

[ydakuka]

The following code raises NameError error, because the result variable is defined only in the transaction scope.

ActiveRecord::Base.transaction do
  result = 1
end

result # NameError: undefined local variable or method `result'

To fix it I need:

1. to define the result variable before the transaction block

result = nil

ActiveRecord::Base.transaction do
  result = 1
end

result

2. to assign transaction block to the result variable:

result =
  ActiveRecord::Base.transaction do
    1
  end

3. to replace local variable with instance variable:

ActiveRecord::Base.transaction do
  @result = 1
end

@result

Which way is better?