[#2349] Made :skip_plug/2 prevent plug from being executed even if explicitly called. Refactoring. Tests.

test/plugs/oauth_scopes_plug_test.exs

@@ -7,6 +7,7 @@ defmodule Pleroma.Plugs.OAuthScopesPlugTest do
 
   alias Pleroma.Plugs.EnsurePublicOrAuthenticatedPlug
   alias Pleroma.Plugs.OAuthScopesPlug
+  alias Pleroma.Plugs.PlugHelper
   alias Pleroma.Repo
 
   import Mock
@@ -16,6 +17,18 @@ defmodule Pleroma.Plugs.OAuthScopesPlugTest do
     :ok
   end
 
+  test "is not performed if marked as skipped", %{conn: conn} do
+    with_mock OAuthScopesPlug, [:passthrough], perform: &passthrough([&1, &2]) do
+      conn =
+        conn
+        |> PlugHelper.append_to_skipped_plugs(OAuthScopesPlug)
+        |> OAuthScopesPlug.call(%{scopes: ["random_scope"]})
+
+      refute called(OAuthScopesPlug.perform(:_, :_))
+      refute conn.halted
+    end
+  end
+
   test "if `token.scopes` fulfills specified 'any of' conditions, " <>
          "proceeds with no op",
        %{conn: conn} do

test/web/auth/oauth_test_controller_test.exs

@@ -0,0 +1,49 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Tests.OAuthTestControllerTest do
+  use Pleroma.Web.ConnCase
+
+  import Pleroma.Factory
+
+  setup %{conn: conn} do
+    user = insert(:user)
+    conn = assign(conn, :user, user)
+    %{conn: conn, user: user}
+  end
+
+  test "missed_oauth", %{conn: conn} do
+    res =
+      conn
+      |> get("/test/authenticated_api/missed_oauth")
+      |> json_response(403)
+
+    assert res ==
+             %{
+               "error" =>
+                 "Security violation: OAuth scopes check was neither handled nor explicitly skipped."
+             }
+  end
+
+  test "skipped_oauth", %{conn: conn} do
+    conn
+    |> assign(:token, nil)
+    |> get("/test/authenticated_api/skipped_oauth")
+    |> json_response(200)
+  end
+
+  test "performed_oauth", %{user: user} do
+    %{conn: good_token_conn} = oauth_access(["read"], user: user)
+
+    good_token_conn
+    |> get("/test/authenticated_api/performed_oauth")
+    |> json_response(200)
+
+    %{conn: bad_token_conn} = oauth_access(["follow"], user: user)
+
+    bad_token_conn
+    |> get("/test/authenticated_api/performed_oauth")
+    |> json_response(403)
+  end
+end