From 6f60ac9f41d9511afa71986f000a2fc6c637b0c5 Mon Sep 17 00:00:00 2001
From: Roman Chvanikov <chvanikoff@pm.me>
Date: Wed, 5 Aug 2020 13:00:49 +0300
Subject: [PATCH] Refactor config

---
 lib/pleroma/config.ex                  | 61 ++++++++++++++++------------------
 test/application_requirements_test.exs |  5 ++-
 test/config_test.exs                   | 16 +++++++++
 3 files changed, 49 insertions(+), 33 deletions(-)

diff --git a/lib/pleroma/config.ex b/lib/pleroma/config.ex
index 88d1972ba..98099ca58 100644
--- a/lib/pleroma/config.ex
+++ b/lib/pleroma/config.ex
@@ -11,33 +11,11 @@ defmodule Pleroma.Config do
 
   def get([key], default), do: get(key, default)
 
-  def get([root_key | keys], default) do
-    # This is to mimic Application.get_env/3 behaviour that returns `nil` if the
-    # actual value is `nil`.
-    Enum.reduce_while(keys, Application.get_env(:pleroma, root_key), fn key, config ->
-      case key do
-        [last_key] when is_map(config) ->
-          {:halt, Map.get(config, last_key, default)}
-
-        [last_key] when is_list(config) ->
-          {:halt, Keyword.get(config, last_key, default)}
-
-        _ ->
-          case config do
-            %{^key => value} ->
-              {:cont, value}
-
-            [_ | _] ->
-              case :lists.keyfind(key, 1, config) do
-                {_, value} -> {:cont, value}
-                _ -> {:halt, default}
-              end
-
-            _ ->
-              {:halt, default}
-          end
-      end
-    end)
+  def get([_ | _] = path, default) do
+    case fetch(path) do
+      {:ok, value} -> value
+      :error -> default
+    end
   end
 
   def get(key, default) do
@@ -54,6 +32,22 @@ defmodule Pleroma.Config do
     end
   end
 
+  def fetch([root_key | keys]) do
+    Enum.reduce_while(keys, Application.fetch_env(:pleroma, root_key), fn
+      key, {:ok, config} when is_map(config) or is_list(config) ->
+        case Access.fetch(config, key) do
+          :error ->
+            {:halt, :error}
+
+          value ->
+            {:cont, value}
+        end
+
+      _key, _config ->
+        {:halt, :error}
+    end)
+  end
+
   def put([key], value), do: put(key, value)
 
   def put([parent_key | keys], value) do
@@ -70,12 +64,15 @@ defmodule Pleroma.Config do
 
   def delete([key]), do: delete(key)
 
-  def delete([parent_key | keys]) do
-    {_, parent} =
-      Application.get_env(:pleroma, parent_key)
-      |> get_and_update_in(keys, fn _ -> :pop end)
+  def delete([parent_key | keys] = path) do
+    with {:ok, _} <- fetch(path) do
+      {_, parent} =
+        parent_key
+        |> get()
+        |> get_and_update_in(keys, fn _ -> :pop end)
 
-    Application.put_env(:pleroma, parent_key, parent)
+      Application.put_env(:pleroma, parent_key, parent)
+    end
   end
 
   def delete(key) do
diff --git a/test/application_requirements_test.exs b/test/application_requirements_test.exs
index 21d24ddd0..e96295955 100644
--- a/test/application_requirements_test.exs
+++ b/test/application_requirements_test.exs
@@ -127,7 +127,10 @@ defmodule Pleroma.ApplicationRequirementsTest do
       :ok
     end
 
-    setup do: clear_config([:i_am_aware_this_may_cause_data_loss, :disable_migration_check])
+    setup do
+      Pleroma.Config.get(:i_am_aware_this_may_cause_data_loss, 42) |> IO.inspect()
+      clear_config([:i_am_aware_this_may_cause_data_loss, :disable_migration_check])
+    end
 
     test "raises if it detects unapplied migrations" do
       assert_raise Pleroma.ApplicationRequirements.VerifyError,
diff --git a/test/config_test.exs b/test/config_test.exs
index 3f3da06d0..e2c18304e 100644
--- a/test/config_test.exs
+++ b/test/config_test.exs
@@ -117,5 +117,21 @@ defmodule Pleroma.ConfigTest do
     Pleroma.Config.put([:delete_me, :delete_me], hello: "world", world: "Hello")
     Pleroma.Config.delete([:delete_me, :delete_me, :world])
     assert Pleroma.Config.get([:delete_me, :delete_me]) == [hello: "world"]
+
+    assert Pleroma.Config.delete([:this_key_does_not_exist])
+    assert Pleroma.Config.delete([:non, :existing, :key])
+  end
+
+  test "fetch/1" do
+    Pleroma.Config.put([:lorem], :ipsum)
+    Pleroma.Config.put([:ipsum], dolor: :sit)
+
+    assert Pleroma.Config.fetch([:lorem]) == {:ok, :ipsum}
+    assert Pleroma.Config.fetch([:ipsum, :dolor]) == {:ok, :sit}
+    assert Pleroma.Config.fetch([:lorem, :ipsum]) == :error
+    assert Pleroma.Config.fetch([:loremipsum]) == :error
+
+    Pleroma.Config.delete([:lorem])
+    Pleroma.Config.delete([:ipsum])
   end
 end