Add optional task to generate style.css.json file before trying to read

lib/ex_css_modules/ex_css_modules.ex

@@ -31,18 +31,26 @@ defmodule ExCSSModules do
       %{}
 
   """
-  @spec stylesheet(String.t() | map()) :: map()
-  def stylesheet(definition) when is_map(definition), do: definition
-  def stylesheet(definition), do: read_stylesheet(definition)
-
-  defp read_stylesheet(filename) do
-    case File.exists?(filename) do
-      true ->
+  @spec stylesheet(String.t() | map(), module()) :: map()
+  def stylesheet(definition, task \\ nil)
+  def stylesheet(definition, _task) when is_map(definition), do: definition
+  def stylesheet(definition, task), do: read_stylesheet(definition, task)
+
+  defp read_stylesheet(filename, task) do
+    cond do
+      File.exists?(filename <> ".json") ->
         (filename <> ".json")
         |> File.read!()
         |> json_library().decode!()
 
-      false ->
+      task && File.exists?(filename) ->
+        with {:ok, json_filename} <- task.run(filename: filename) do
+          json_filename
+          |> File.read!()
+          |> json_library().decode!()
+        end
+
+      true ->
         %{}
     end
   end

lib/ex_css_modules/view.ex

@@ -29,19 +29,20 @@ defmodule ExCSSModules.View do
       )
 
     filename = Path.expand(filename, Path.dirname(relative_to))
+    generate_scoped_name_task = Keyword.get(opts, :generate_scoped_name_task)
 
     quote do
       @stylesheet unquote(
                     if embed_stylesheet? do
-                      Macro.escape(ExCSSModules.stylesheet(filename))
+                      Macro.escape(ExCSSModules.stylesheet(filename, generate_scoped_name_task))
                     else
                       Macro.escape(filename)
                     end
                   )
 
       def stylesheet_definition, do: @stylesheet
 
-      def stylesheet, do: ExCSSModules.stylesheet(@stylesheet)
+      def stylesheet, do: ExCSSModules.stylesheet(@stylesheet, unquote(generate_scoped_name_task))
 
       def class(key), do: stylesheet() |> ExCSSModules.class(key)
       def class(key, value), do: stylesheet() |> ExCSSModules.class(key, value)