instance.gen task: fix crash when using custom static directory

Closes #1082

lib/mix/tasks/pleroma/instance.ex

@@ -6,6 +6,8 @@ defmodule Mix.Tasks.Pleroma.Instance do
   use Mix.Task
   import Mix.Pleroma
 
+  alias Pleroma.Config
+
   @shortdoc "Manages Pleroma instance"
   @moduledoc File.read!("docs/administration/CLI_tasks/instance.md")
 
@@ -153,6 +155,8 @@ defmodule Mix.Tasks.Pleroma.Instance do
           Pleroma.Config.get([:instance, :static_dir])
         )
 
+      Config.put([:instance, :static_dir], static_dir)
+
       secret = :crypto.strong_rand_bytes(64) |> Base.encode64() |> binary_part(0, 64)
       jwt_secret = :crypto.strong_rand_bytes(64) |> Base.encode64() |> binary_part(0, 64)
       signing_salt = :crypto.strong_rand_bytes(8) |> Base.encode64() |> binary_part(0, 8)

test/tasks/instance_test.exs

@@ -3,9 +3,10 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.InstanceTest do
-  use ExUnit.Case, async: true
+  use ExUnit.Case
 
   setup do
+    static_dir = Pleroma.Config.get([:instance, :static_dir])
     File.mkdir_p!(tmp_path())
 
     on_exit(fn ->
@@ -15,6 +16,8 @@ defmodule Pleroma.InstanceTest do
       if File.exists?(static_dir) do
         File.rm_rf(Path.join(static_dir, "robots.txt"))
       end
+
+      Pleroma.Config.put([:instance, :static_dir], static_dir)
     end)
 
     :ok