Var exposed from the scope without return

[define-null]

Just an idea - it would be nice to make elvis warn about the situations when variable is exposed from the scope without doing that explicitly, like this:

case some_function() of
    opt1 ->
         ... some code here ...
         Var = some_other_fun()
         ... some code here as well ..
    opt2 ->
         ... some code here ...
         Var = some_other_fun2()
         ... some code here as well ...
end,

other_function(Var)

Where the good code imho would do smth like:

{Var, Rest...} = case some_function() of
    opt1 ->
         ... some code here ...
         V = some_other_fun()
         ... some code here as well ..
         {V, R...}
    opt2 ->
         ... some code here ...
         V = some_other_fun2()
         ... some code here as well ...
         {V, R...}
end,

other_function(Var)

[elbrujohalcon]

I love this rule idea!

[paulo-ferraz-oliveira]

I get a compilation warning if I attempt to "expose from scope".

variable 'V' exported from 'case'

I'm on Erlang/OTP 23, using rebar3 with erl_opts [warnings_as_errors, debug_info, warn_missing_spec_all, warn_export_vars, warn_unused_import].

[elbrujohalcon]

Yeah, warn_export_vars does the trick :)