Supported Setting for Cache Adapter

lib/open_api_spex/plug/cache.ex

@@ -1,50 +1,113 @@
 defmodule OpenApiSpex.Plug.Cache do
-  @moduledoc false
+  @moduledoc """
+  Cache for OpenApiSpex
 
-  @callback get(module) :: {OpenApiSpex.OpenApi.t(), map} | nil
-  @callback put(module, {OpenApiSpex.OpenApi.t(), map}) :: :ok
+  Settings:
 
-  @spec adapter() :: OpenApiSpex.Plug.AppEnvCache | OpenApiSpex.Plug.PersistentTermCache
-  def adapter do
-    if function_exported?(:persistent_term, :info, 0) do
+  ```elixir
+  config :open_api_spex, :cache_adapter Module
+  ```
+
+  There are already had three cache adapter:
+  * `OpenApiSpex.Plug.PersistentTermCache` - default
+  * `OpenApiSpex.Plug.AppEnvCache` - if VM not supported `persistent_term`
+  * `OpenApiSpex.Plug.NoneCache` - none cache
+
+  If you are constantly modifying specs during development, you can setting
+  like this in `dev.exs`:
+
+  ```elixir
+  config :open_api_spex, :cache_adapter OpenApiSpex.Plug.NoneCache
+  ```
+  """
+
+  default_adapter =
+    if(function_exported?(:persistent_term, :info, 0)) do
       OpenApiSpex.Plug.PersistentTermCache
     else
       OpenApiSpex.Plug.AppEnvCache
     end
+
+  @default_adapter default_adapter
+
+  @callback get(module) :: {OpenApiSpex.OpenApi.t(), map} | nil
+  @callback put(module, {OpenApiSpex.OpenApi.t(), map}) :: :ok
+  @callback erase(module) :: :ok
+
+  @doc """
+  Get cache adapter
+  """
+  @spec adapter() :: module()
+  def adapter do
+    Application.get_env(:open_api_spex, :cache_adapter, @default_adapter)
+  end
+
+  @doc """
+  Only erase cache, put again when plug starting
+  """
+  @spec refresh() :: :ok
+  def refresh do
+    adapter = adapter()
+    adapter.erase()
   end
 end
 
 defmodule OpenApiSpex.Plug.AppEnvCache do
   @moduledoc false
   @behaviour OpenApiSpex.Plug.Cache
 
-  @impl OpenApiSpex.Plug.Cache
+  @impl true
   def get(spec_module) do
     Application.get_env(:open_api_spex, spec_module)
   end
 
-  @impl OpenApiSpex.Plug.Cache
+  @impl true
   def put(spec_module, spec) do
     :ok = Application.put_env(:open_api_spex, spec_module, spec)
   end
+
+  @impl true
+  def erase(spec_module) do
+    Application.delete_env(:open_api_spex, spec_module)
+  end
 end
 
 if function_exported?(:persistent_term, :info, 0) do
   defmodule OpenApiSpex.Plug.PersistentTermCache do
     @moduledoc false
     @behaviour OpenApiSpex.Plug.Cache
 
-    @impl OpenApiSpex.Plug.Cache
+    @impl true
     def get(spec_module) do
       :persistent_term.get(spec_module)
     rescue
       ArgumentError ->
         nil
     end
 
-    @impl OpenApiSpex.Plug.Cache
+    @impl true
     def put(spec_module, spec) do
       :ok = :persistent_term.put(spec_module, spec)
     end
+
+    @impl true
+    def erase(spec_module) do
+      :persistent_term.erase(spec_module)
+      :ok
+    end
   end
 end
+
+defmodule OpenApiSpex.Plug.NoneCache do
+  @moduledoc false
+  @behaviour OpenApiSpex.Plug.Cache
+
+  @impl true
+  def get(_spec_module), do: nil
+
+  @impl true
+  def put(_spec_module, _spec), do: :ok
+
+  @impl true
+  def erase(_spec_module), do: :ok
+end