required fields from changeset

lib/mix/tasks/swagger.ex

@@ -246,6 +246,13 @@ defmodule Mix.Tasks.Swagger do
       end
 
       module_json = %{"properties" => properties_json}
+
+      if :erlang.function_exported(module, :changeset, 2) do
+        module_struct = module.changeset(module.__struct__, %{})
+        required = required_fields module_struct.errors
+        module_json = Map.put(module_json, "required", required)
+      end
+
       def_json = Map.put(def_json, "#{inspect module}", module_json)
     end
 
@@ -273,4 +280,12 @@ defmodule Mix.Tasks.Swagger do
       _ -> %{"type" => "string"}
     end
   end
+
+  def required_fields([]), do: []
+
+  def required_fields([head|tail]) do
+    {key, _msg} = head
+    [to_string(key)|required_fields(tail)]
+  end
+
 end

test/mix/tasks/swagger_test.exs

@@ -356,7 +356,18 @@ defmodule Mix.Tasks.Swagger.Tests do
 
   test "build_definitions - modules but no models" do
     assert Swagger.build_definitions([{Mocks.DefaultPlug, ""}], %{}) == %{}
-  end    
+  end 
+
+  #==============================
+  # required_fields tests
+
+  test "required_fields - parse errors from struct, if errors is empty" do
+    assert Swagger.required_fields([]) == []
+  end
+
+  test "required_fields - parse errors from struct" do
+    assert Swagger.required_fields([name: "can't be blank", email: "can't be blank"]) == ["name", "email"]
+  end
 
   test "build_definitions - model" do
     assert Swagger.build_definitions([{Mocks.UserModel, ""}], %{}) == %{
@@ -376,16 +387,17 @@ defmodule Mix.Tasks.Swagger.Tests do
   test "build_definitions - model support changeset (required_fields)" do
     assert Swagger.build_definitions([{Mocks.UserRequiredModel, ""}], %{}) == %{
       "Mocks.UserRequiredModel" => %{
-        #"required" => ["email", "name"],
         "properties" => %{
           "bio" => %{"type" => "string"}, 
           "email" => %{"type" => "string"},
           "id" => %{"format" => "int64", "type" => "integer"},
           "inserted_at" => %{"format" => "date-time", "type" => "string"}, 
           "name" => %{"type" => "string"},
           "number_of_pets" => %{"format" => "int64", "type" => "integer"},
-          "updated_at" => %{"format" => "date-time", "type" => "string"}}
-        }
+          "updated_at" => %{"format" => "date-time", "type" => "string"}
+        },
+        "required" => ["name", "email"]
+      }
     }
   end    
 
@@ -452,7 +464,7 @@ defmodule Mix.Tasks.Swagger.Tests do
   test "run raise exception" do
     :meck.new(Swagger, [:passthrough])
     :meck.expect(Swagger, :get_router, fn _ -> Mocks.SimpleRouter end)
-    #:meck.expect(Swagger, :add_routes, fn _,_ -> raise "bad news bears" end)
+    :meck.expect(Swagger, :add_routes, fn _,_ -> raise "bad news bears" end)
 
     assert Swagger.run(nil) == :ok
   after