function run_test() { var stream = Cc["@mozilla.org/io/string-input-stream;1"]. createInstance(Ci.nsISupportsCString); stream.data = "foo bar baz"; var pump = Cc["@mozilla.org/network/input-stream-pump;1"]. createInstance(Ci.nsIInputStreamPump); pump.init(stream, -1, -1, 0, 0, false); // When we pass a null listener argument too asyncRead we expect it to throw // instead of crashing. try { pump.asyncRead(null, null); } catch (e) { return; } do_throw("asyncRead didn't throw when passed a null listener argument."); }