chore(httpproxy): add Test_returnRedirect to prevent error wrap of ErrUseLastResponse

internal/httpproxy/handler_test.go

@@ -0,0 +1,16 @@
+package httpproxy
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_returnRedirect(t *testing.T) {
+	t.Parallel()
+
+	err := returnRedirect(nil, nil)
+
+	assert.Equal(t, http.ErrUseLastResponse, err)
+}