it is changed in compile time

we can't change module attributes and endpoint settings in runtime

test/web/admin_api/config_test.exs

@@ -0,0 +1,183 @@
+defmodule Pleroma.Web.AdminAPI.ConfigTest do
+  use Pleroma.DataCase, async: true
+  import Pleroma.Factory
+  alias Pleroma.Web.AdminAPI.Config
+
+  test "get_by_key/1" do
+    config = insert(:config)
+    insert(:config)
+
+    assert config == Config.get_by_key(config.key)
+  end
+
+  test "create/1" do
+    {:ok, config} = Config.create(%{key: "some_key", value: "some_value"})
+    assert config == Config.get_by_key("some_key")
+  end
+
+  test "update/1" do
+    config = insert(:config)
+    {:ok, updated} = Config.update(config, %{value: "some_value"})
+    loaded = Config.get_by_key(config.key)
+    assert loaded == updated
+  end
+
+  test "update_or_create/1" do
+    config = insert(:config)
+    key2 = "another_key"
+
+    params = [
+      %{key: key2, value: "another_value"},
+      %{key: config.key, value: "new_value"}
+    ]
+
+    assert Repo.all(Config) |> length() == 1
+
+    Enum.each(params, &Config.update_or_create(&1))
+
+    assert Repo.all(Config) |> length() == 2
+
+    config1 = Config.get_by_key(config.key)
+    config2 = Config.get_by_key(key2)
+
+    assert config1.value == Config.transform("new_value")
+    assert config2.value == Config.transform("another_value")
+  end
+
+  test "delete/1" do
+    config = insert(:config)
+    {:ok, _} = Config.delete(config.key)
+    refute Config.get_by_key(config.key)
+  end
+
+  describe "transform/1" do
+    test "string" do
+      binary = Config.transform("value as string")
+      assert binary == :erlang.term_to_binary("value as string")
+      assert Config.from_binary(binary) == "value as string"
+    end
+
+    test "list of modules" do
+      binary = Config.transform(["Pleroma.Repo", "Pleroma.Activity"])
+      assert binary == :erlang.term_to_binary([Pleroma.Repo, Pleroma.Activity])
+      assert Config.from_binary(binary) == [Pleroma.Repo, Pleroma.Activity]
+    end
+
+    test "list of strings" do
+      binary = Config.transform(["string1", "string2"])
+      assert binary == :erlang.term_to_binary(["string1", "string2"])
+      assert Config.from_binary(binary) == ["string1", "string2"]
+    end
+
+    test "map" do
+      binary =
+        Config.transform(%{
+          "types" => "Pleroma.PostgresTypes",
+          "telemetry_event" => ["Pleroma.Repo.Instrumenter"],
+          "migration_lock" => ""
+        })
+
+      assert binary ==
+               :erlang.term_to_binary(
+                 telemetry_event: [Pleroma.Repo.Instrumenter],
+                 types: Pleroma.PostgresTypes
+               )
+
+      assert Config.from_binary(binary) == [
+               telemetry_event: [Pleroma.Repo.Instrumenter],
+               types: Pleroma.PostgresTypes
+             ]
+    end
+
+    test "complex map with nested integers, lists and atoms" do
+      binary =
+        Config.transform(%{
+          "uploader" => "Pleroma.Uploaders.Local",
+          "filters" => ["Pleroma.Upload.Filter.Dedupe"],
+          "link_name" => ":true",
+          "proxy_remote" => ":false",
+          "proxy_opts" => %{
+            "redirect_on_failure" => ":false",
+            "max_body_length" => "i:1048576",
+            "http" => %{
+              "follow_redirect" => ":true",
+              "pool" => ":upload"
+            }
+          }
+        })
+
+      assert binary ==
+               :erlang.term_to_binary(
+                 filters: [Pleroma.Upload.Filter.Dedupe],
+                 link_name: true,
+                 proxy_opts: [
+                   http: [
+                     follow_redirect: true,
+                     pool: :upload
+                   ],
+                   max_body_length: 1_048_576,
+                   redirect_on_failure: false
+                 ],
+                 proxy_remote: false,
+                 uploader: Pleroma.Uploaders.Local
+               )
+
+      assert Config.from_binary(binary) ==
+               [
+                 filters: [Pleroma.Upload.Filter.Dedupe],
+                 link_name: true,
+                 proxy_opts: [
+                   http: [
+                     follow_redirect: true,
+                     pool: :upload
+                   ],
+                   max_body_length: 1_048_576,
+                   redirect_on_failure: false
+                 ],
+                 proxy_remote: false,
+                 uploader: Pleroma.Uploaders.Local
+               ]
+    end
+
+    test "keyword" do
+      binary =
+        Config.transform(%{
+          "level" => ":warn",
+          "meta" => [":all"],
+          "webhook_url" => "https://hooks.slack.com/services/YOUR-KEY-HERE"
+        })
+
+      assert binary ==
+               :erlang.term_to_binary(
+                 level: :warn,
+                 meta: [:all],
+                 webhook_url: "https://hooks.slack.com/services/YOUR-KEY-HERE"
+               )
+
+      assert Config.from_binary(binary) == [
+               level: :warn,
+               meta: [:all],
+               webhook_url: "https://hooks.slack.com/services/YOUR-KEY-HERE"
+             ]
+    end
+
+    test "complex map with sigil" do
+      binary =
+        Config.transform(%{
+          federated_timeline_removal: [],
+          reject: [~r/comp[lL][aA][iI][nN]er/],
+          replace: []
+        })
+
+      assert binary ==
+               :erlang.term_to_binary(
+                 federated_timeline_removal: [],
+                 reject: [~r/comp[lL][aA][iI][nN]er/],
+                 replace: []
+               )
+
+      assert Config.from_binary(binary) ==
+               [federated_timeline_removal: [], reject: [~r/comp[lL][aA][iI][nN]er/], replace: []]
+    end
+  end
+end