Fix false positive for UnusedKeywordOperation

Refs #1128

Author: rrrene

lib/credo/check/warning/unused_keyword_operation.ex

@@ -34,7 +34,49 @@ defmodule Credo.Check.Warning.UnusedKeywordOperation do
   alias Credo.Check.Warning.UnusedOperation
 
   @checked_module :Keyword
-  @funs_with_return_value nil
+  @funs_with_return_value [
+    :delete,
+    :delete_first,
+    :drop,
+    :equal?,
+    :fetch,
+    :fetch!,
+    :filter,
+    :from_keys,
+    :get,
+    :get_and_update,
+    :get_and_update!,
+    :get_lazy,
+    :get_values,
+    :has_key?,
+    :keys,
+    :keyword?,
+    :merge,
+    :merge,
+    :new,
+    :new,
+    :new,
+    :pop,
+    :pop!,
+    :pop_first,
+    :pop_lazy,
+    :pop_values,
+    :put,
+    :put_new,
+    :put_new_lazy,
+    :reject,
+    :replace,
+    :replace!,
+    :replace_lazy,
+    :split,
+    :split_with,
+    :take,
+    :to_list,
+    :update,
+    :update!,
+    :validate,
+    :values
+  ]
 
   @doc false
   @impl true

test/credo/check/warning/unused_keyword_operation_test.exs

@@ -11,6 +11,8 @@ defmodule Credo.Check.Warning.UnusedKeywordOperationTest do
     """
     defmodule CredoSampleModule do
       def some_function(parameter1, parameter2) do
+        Keyword.validate!(opts, [:base_url, :meta, :receive_timeout])
+
         Keyword.values(parameter1) + parameter2
       end