add monitor tests

tests/tests.R

@@ -87,6 +87,7 @@ test_zero(n$send(1:5, mode = "r"))
 test_equal(length(n1$recv("int", block = 500)), 5L)
 test_true(is_aio(saio <- n1$send_aio(paste(replicate(5, random(1e3L)), collapse = ""), mode = 1L, timeout = 900)))
 test_print(saio)
+if (later) test_null(.keep(saio, new.env()))
 test_class("sendAio", call_aio(saio))
 test_zero(saio$result)
 test_error(n$send("wrong mode", mode = "none"), "mode")
@@ -387,6 +388,9 @@ test_zero(reap(poly2))
 test_zero(reap(poly1))
 test_true(wait(cv))
 test_type("integer", read_monitor(m))
+test_error(read_monitor(poly), "valid Monitor")
+test_error(monitor("socket", "cv"), "valid Socket")
+test_error(monitor(poly, "cv"), "valid Condition Variable")
 test_zero(reap(poly))
 
 test_class("nanoSocket", bus <- socket(protocol = "bus"))