Fix new credo warnings

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/federation/web_finger/web_finger.ex

@@ -189,7 +189,7 @@ defmodule Mobilizon.Federation.WebFinger do
           {:ok, String.t()} | {:error, :link_not_found} | {:error, any()}
   defp find_webfinger_endpoint(domain) when is_binary(domain) do
     with {:ok, %Tesla.Env{status: 200, body: body}} <-
-           fetch_document("http://#{domain}/.well-known/host-meta"),
+           HostMetaClient.get("http://#{domain}/.well-known/host-meta"),
          link_template when is_binary(link_template) <- find_link_from_template(body) do
       {:ok, link_template}
     else
@@ -258,11 +258,6 @@ defmodule Mobilizon.Federation.WebFinger do
       {:error, :link_not_found}
   end
 
-  @spec fetch_document(String.t()) :: Tesla.Env.result()
-  defp fetch_document(endpoint) do
-    with {:error, err} <- HostMetaClient.get(endpoint), do: {:error, err}
-  end
-
   @spec address_invalid(String.t()) :: false | {:error, :invalid_address}
   defp address_invalid(address) do
     with %URI{host: host, scheme: scheme} <- URI.parse(address),

lib/federation/web_finger/xml_builder.ex

@@ -39,9 +39,7 @@ defmodule Mobilizon.Federation.WebFinger.XmlBuilder do
   defp to_xml(content) when is_binary(content), do: to_string(content)
 
   defp to_xml(content) when is_list(content) do
-    content
-    |> Enum.map(&to_xml/1)
-    |> Enum.join()
+    Enum.map_join(content, &to_xml/1)
   end
 
   defp to_xml(%NaiveDateTime{} = time), do: NaiveDateTime.to_iso8601(time)
@@ -49,9 +47,7 @@ defmodule Mobilizon.Federation.WebFinger.XmlBuilder do
   @spec make_open_tag(tag :: atom, attributes :: map()) :: String.t()
   defp make_open_tag(tag, attributes) do
     attributes_string =
-      attributes
-      |> Enum.map(fn {attribute, value} -> "#{attribute}=\"#{value}\"" end)
-      |> Enum.join(" ")
+      Enum.map_join(attributes, " ", fn {attribute, value} -> "#{attribute}=\"#{value}\"" end)
 
     [to_string(tag), attributes_string] |> Enum.join(" ") |> String.trim()
   end