No String as Id

What is it?

This is a simple rule for the elm-review tool that will help flagging cases where Ids are represented as String. It is quite often the case that we see the following pattern in elm code:

type alias Stuff =
  { id: String,
  , ...
  }

However, this leads to many confusing calls on function dealing with both stuffs and things:

function: String -> String -> List String -> List Something -> SomethingElse
function stuffId thingId stuffs things =
  ...

Instead it would be much nicer to have something like this:

type StuffId =
  StuffId String

type ThingId =
  ThingId String

type alias Stuff =
  { id: StuffId
  , ...
  }


function: StuffId -> ThingId -> List StuffId -> List Something -> SomethingElse
function stuffId thingId stuffIds things =
  ...

Which makes it much harder to mess-up the arguments' order or to feed SomethingId instead of a StuffId...

Why should you use it?

• if you are fed up of double checking that you're passing stuff in the right order
• if you are a fan of making impossible things impossible and make sure the compiler help you in case you change the argument order or the argument types

Why should you not use it?

• if you do not like easy refactoring.
• if you do not care about String being used for something else that what they are.
• if you do not want to setup elm-review.
• ...

Example configuration

import NoStringAsId
import Review.Rule exposing (Rule)

config : List Rule
config =
  [ NoStringAsId.rule
  ]