Reports when a variable between case .. of is used in any of the cases

config =
    [ VariablesBetweenCaseOf.AccessInCases.forbid
    ]

reported

case arguments of
    [] ->
        "no arguments"


    _ :: _ ->
        arguments |> String.join ", "

The rule collects variables even inside tuples, variants and lists.

not reported

case arguments of
    [] ->
        "no arguments"


    firstArg :: args1Up ->
        (firstArg :: args1Up) |> String.join ", "

The rule does not collect variables inside records, functions, operations, ...

case originalList |> List.drop 4 of
    [] ->
        "less than 5 arguments"


    _ :: _
        originalList |> String.join ", "

When (not) to use

This rule is not useful when you would fix

case list of
    [] ->
        "no arguments"


    _ :: _ ->
        list |> String.join ", "

to

case list of
    [] ->
        "no arguments"


    list_ ->
        list_ |> String.join ", "

That's not the purpose of this rule!

The motivation is preventing you from forgetting to use certain information and referring to the wrong variables. For more details, check the readme