fix: do not fetch peri parser on raw data schemas (#10)

lib/peri.ex

@@ -583,7 +583,9 @@ defmodule Peri do
   end
 
   defp validate_field(val, {:cond, condition, true_type, else_type}, parser) do
-    if condition.(parser.root_data) do
+    root = maybe_get_root_data(parser)
+
+    if condition.(root) do
       validate_field(val, true_type, parser)
     else
       validate_field(val, else_type, parser)
@@ -592,7 +594,9 @@ defmodule Peri do
 
   defp validate_field(val, {:dependent, callback}, parser)
        when is_function(callback, 1) do
-    with {:ok, type} <- callback.(parser.root_data),
+    root = maybe_get_root_data(parser)
+
+    with {:ok, type} <- callback.(root),
          {:ok, schema} <- validate_schema(type) do
       validate_field(val, schema, parser)
     end
@@ -725,7 +729,7 @@ defmodule Peri do
   end
 
   defp validate_field(data, schema, p) when is_enumerable(data) do
-    root = p.root_data
+    root = maybe_get_root_data(p)
 
     case traverse_schema(schema, Peri.Parser.new(data, root_data: root)) do
       %Peri.Parser{errors: []} = parser -> {:ok, parser.data}
@@ -738,6 +742,10 @@ defmodule Peri do
     {:error, "expected type of %{expected} received %{actual} value", info}
   end
 
+  # if schema is matches a raw data structure, it will not use the Peri.Parser
+  defp maybe_get_root_data(%Peri.Parser{} = p), do: p.root_data
+  defp maybe_get_root_data(data), do: data
+
   @doc """
   Validates a schema definition to ensure it adheres to the expected structure and types.