The in? predicate raises an exception for single-element lists.

[ndan]

The in? predicate raises an exception when the list contains a single element.

defmodule Contract do
  use Drops.Contract

  schema do
    %{
      optional(:side) => string(in?: ["salad"]),
      optional(:meat) => string(in?: ["chicken", "beef"])
    }
  end
end

Contract.conform(%{meat: "chicken"}) # => {:ok, %{meat: "chicken"}}

Contract.conform(%{side: "salad"})

# ** (FunctionClauseError) no function clause matching in Drops.Predicates.in?/2
# 
#     The following arguments were given to Drops.Predicates.in?/2:
# 
#         # 1
#         "salad"
# 
#         # 2
#         "salad"
# 
#     Attempted function clauses (showing 1 out of 1):
# 
#         def in?(list, input) when is_list(list)
# 
#     (drops 0.2.0) lib/drops/predicates.ex:377: Drops.Predicates.in?/2
#     (drops 0.2.0) lib/drops/predicates/helpers.ex:22: Drops.Predicates.Helpers.apply_predicate/2
#     (elixir 1.17.1) lib/enum.ex:2531: Enum."-reduce/3-lists^foldl/2-0-"/3
#     (drops 0.2.0) lib/drops/types/map/key.ex:15: Drops.Types.Map.Key.validate/2
#     (elixir 1.17.1) lib/enum.ex:1703: Enum."-map/2-lists^map/1-1-"/2
#     (elixir 1.17.1) lib/enum.ex:1703: Enum."-map/2-lists^map/1-1-"/2
#     (drops 0.2.0) lib/drops/types/map.ex:63: Drops.Types.Map.Validator.validate/2
#     iex:6: Contract.conform/3

[solnic]

Ah thanks for reporting this. I'll fix it in the next release sometime next week :)