Fix trigger in NegatedConditionsInUnless

lib/credo/check/refactor/negated_conditions_in_unless.ex

@@ -36,9 +36,13 @@ defmodule Credo.Check.Refactor.NegatedConditionsInUnless do
     {nil, issues}
   end
 
-  defp traverse({:unless, _meta, arguments} = ast, issues, issue_meta)
-       when is_list(arguments) do
-    issue = issue_for_first_condition(List.first(arguments), issue_meta)
+  defp traverse(
+         {:unless, _meta, [{negator, meta, _arguments} | _]} = ast,
+         issues,
+         issue_meta
+       )
+       when negator in [:!, :not] do
+    issue = issue_for(issue_meta, meta[:line], negator)
 
     {ast, issues ++ List.wrap(issue)}
   end
@@ -47,12 +51,6 @@ defmodule Credo.Check.Refactor.NegatedConditionsInUnless do
     {ast, issues}
   end
 
-  defp issue_for_first_condition({:!, meta, _arguments}, issue_meta) do
-    issue_for(issue_meta, meta[:line], "!")
-  end
-
-  defp issue_for_first_condition(_, _), do: nil
-
   defp issue_for(issue_meta, line_no, trigger) do
     format_issue(
       issue_meta,

test/credo/check/refactor/negated_conditions_in_unless_test.exs

@@ -59,4 +59,19 @@ defmodule Credo.Check.Refactor.NegatedConditionsInUnlessTest do
     |> run_check(@described_check)
     |> assert_issue()
   end
+
+  test "it should report a violation with not" do
+    """
+    defmodule CredoSampleModule do
+      def some_function(parameter1, parameter2) do
+        unless not allowed? do
+          something
+        end
+      end
+    end
+    """
+    |> to_source_file
+    |> run_check(@described_check)
+    |> assert_issue()
+  end
 end