fixes for mix tasks

- fix for `mix pleroma.database update_users_following_followers_counts`
- raise error, if fetch was unsuccessful in emoji tasks
- fix for `pleroma.digest test` task

lib/mix/tasks/pleroma/emoji.ex

@@ -15,7 +15,7 @@ defmodule Mix.Tasks.Pleroma.Emoji do
     {options, [], []} = parse_global_opts(args)
 
     url_or_path = options[:manifest] || default_manifest()
-    manifest = fetch_and_decode(url_or_path)
+    manifest = fetch_and_decode!(url_or_path)
 
     Enum.each(manifest, fn {name, info} ->
       to_print = [
@@ -42,7 +42,7 @@ defmodule Mix.Tasks.Pleroma.Emoji do
 
     url_or_path = options[:manifest] || default_manifest()
 
-    manifest = fetch_and_decode(url_or_path)
+    manifest = fetch_and_decode!(url_or_path)
 
     for pack_name <- pack_names do
       if Map.has_key?(manifest, pack_name) do
@@ -92,7 +92,7 @@ defmodule Mix.Tasks.Pleroma.Emoji do
           ])
         )
 
-        files = fetch_and_decode(files_loc)
+        files = fetch_and_decode!(files_loc)
 
         IO.puts(IO.ANSI.format(["Unpacking ", :bright, pack_name]))
 
@@ -243,9 +243,11 @@ defmodule Mix.Tasks.Pleroma.Emoji do
     IO.puts("Emoji packs have been reloaded.")
   end
 
-  defp fetch_and_decode(from) do
+  defp fetch_and_decode!(from) do
     with {:ok, json} <- fetch(from) do
       Jason.decode!(json)
+    else
+      {:error, error} -> raise "#{from} cannot be fetched. Error: #{error} occur."
     end
   end