Make type shortcuts work with cast(...)

lib/drops/types/map/dsl.ex

@@ -107,10 +107,14 @@ defmodule Drops.Types.Map.DSL do
     {:type, {type, predicates}}
   end
 
-  def type({:cast, {input_type, cast_opts}}, output_type) do
+  def type({:cast, {input_type, cast_opts}}, output_type) when is_atom(output_type) do
     {:cast, {type(input_type), type(output_type), cast_opts}}
   end
 
+  def type({:cast, {input_type, cast_opts}}, output_type) do
+    {:cast, {type(input_type), output_type, cast_opts}}
+  end
+
   @doc ~S"""
   Returns a list type specification.
 
@@ -227,6 +231,10 @@ defmodule Drops.Types.Map.DSL do
     type(:string, predicates)
   end
 
+  def string({:cast, _} = cast_spec, predicates \\ []) do
+    type(cast_spec, string(predicates))
+  end
+
   @doc ~S"""
   Returns an integer type specification.
 
@@ -269,6 +277,10 @@ defmodule Drops.Types.Map.DSL do
     type(:integer, predicates)
   end
 
+  def integer({:cast, _} = cast_spec, predicates \\ []) do
+    type(cast_spec, integer(predicates))
+  end
+
   @doc ~S"""
   Returns a map type specification.
 

test/contract/casters_test.exs

@@ -6,7 +6,19 @@ defmodule Drops.CastersTest do
   describe ":integer => :string" do
     contract do
       schema do
-        %{required(:test) => cast(:integer) |> type(:string)}
+        %{required(:test) => cast(:integer) |> string()}
+      end
+    end
+
+    test "defining a required key with coercion", %{contract: contract} do
+      assert {:ok, %{test: "12"}} = contract.conform(%{test: 12})
+    end
+  end
+
+  describe ":integer => :string with constraints" do
+    contract do
+      schema do
+        %{required(:test) => cast(:integer) |> string()}
       end
     end
 
@@ -18,7 +30,7 @@ defmodule Drops.CastersTest do
   describe ":string => :integer" do
     contract do
       schema do
-        %{required(:test) => cast(:string) |> type(:integer)}
+        %{required(:test) => cast(:string) |> integer()}
       end
     end