fun_with_router.ex

defmodule TestRouter do
  def build(routes) do
    contents =
      quote do
        use Plug.Router
        
        plug :match
        plug :dispatch      

        Enum.map(unquote(Macro.escape(routes)), fn %{match: match, assign: assign} ->
          get match, [assigns: assign] do
            var!(conn)
          end
        end)
      end
      
    Module.create(__MODULE__.Handler, contents, Macro.Env.location(__ENV__))
  end
end

router = TestRouter.build([
  %{match: "/hello", assign: %{a: 1, b: 2}}, 
  %{match: "/other", assign: %{c: 3, d: "a"}},
  %{match: "/widgets/:id/something/:nested", assign: %{}},
])

conn = TestRouter.Handler.call(Plug.Test.conn(:get, "/widgets/1/something/else", ""), TestRouter.Handler.init([]))
# Will use conn then to provide `params` and certain assigned variables (stored in DB) into the Front Controller