RichMedia: do not log webpages missing metadata as errors

Also fixes the return value of Parser.parse on errors, previously
was just `:ok` due to the logger call in the end

lib/pleroma/web/rich_media/parser.ex

@@ -21,8 +21,13 @@ def parse(url) do
            {:ok, _} <- set_ttl_based_on_image(data, url) do
         {:ok, data}
       else
+        {:error, {:invalid_metadata, data}} = e ->
+          Logger.debug(fn -> "Incomplete or invalid metadata for #{url}: #{inspect(data)}" end)
+          e
+
         error ->
-          Logger.error(fn -> "Rich media error: #{inspect(error)}" end)
+          Logger.error(fn -> "Rich media error for #{url}: #{inspect(error)}" end)
+          error
       end
     end
 
@@ -90,7 +95,7 @@ defp get_ttl_from_image(data, url) do
     end)
   end
 
-  defp parse_url(url) do
+  def parse_url(url) do
     with {:ok, %Tesla.Env{body: html}} <- Pleroma.Web.RichMedia.Helpers.rich_media_get(url),
          {:ok, html} <- Floki.parse_document(html) do
       html
@@ -116,7 +121,7 @@ defp check_parsed_data(%{"title" => title} = data)
   end
 
   defp check_parsed_data(data) do
-    {:error, "Found metadata was invalid or incomplete: #{inspect(data)}"}
+    {:error, {:invalid_metadata, data}}
   end
 
   defp clean_parsed_data(data) do

test/web/rich_media/parser_test.exs

@@ -66,9 +66,7 @@ test "returns error when no metadata present" do
   end
 
   test "doesn't just add a title" do
-    assert Parser.parse("http://example.com/non-ogp") ==
+    assert {:error, {:invalid_metadata, _}} = Parser.parse("http://example.com/non-ogp")
-             {:error,
-              "Found metadata was invalid or incomplete: %{\"url\" => \"http://example.com/non-ogp\"}"}
   end
 
   test "parses ogp" do