new structs to fetch, results and session

lib/feed_reader/fetch.ex

@@ -0,0 +1,21 @@
+defmodule FeedReader.Fetch do
+  @moduledoc """
+  HTTP metadata for a completed remote feed fetch.
+
+  The checksum is calculated from the decoded response body. A fetch is only
+  present on remote results and sessions; local parsing does not invent HTTP
+  metadata.
+  """
+
+  @type t :: %__MODULE__{
+          etag: String.t() | nil,
+          checksum: String.t() | nil,
+          final_url: String.t() | nil,
+          status: pos_integer() | nil
+        }
+
+  defstruct etag: nil,
+            checksum: nil,
+            final_url: nil,
+            status: nil
+end