c# - Unit testing methods with a local Thread -

i have method looks this:

protected void onbarcodescan(barcodescannereventargs e) {     // need on seperate thread don't block main thread.     threadstart starter = () => sendscanmessage(e, _scandelegates);     thread scanthread = new thread(starter);      scanthread.start(); } 

then thread goes off , logic (and ends calling delegate in test).

my problem unit test finishes before thread does. test fails.

i can add in system.threading.thread.sleep(1000); , hope logic never takes more second (it should not). seems hack.

the problem don't want expose thread outside world or rest of class.

is there cool way find thread again , wait in unit test?

something this:

[testmethod] [hosttype("moles")] public void adddelegatetoscanner_scanhappens_scandelegateiscalled() {     // arrange     bool scancalled = false;     mcoredll.gettopwindow = () => (new intptr(fauxhandle));      // act     _scanner.adddelegatetoscanner(_formidentity, ((evnt) => { scancalled = true; }));     _scanner.sendscan(new barcodescannereventargs("12345678910"));      // line fake!     system.threading.thread.coolmethodtofindmythread().join();      // assert     assert.istrue(scancalled); } 

i made coolmethodtofindmythread method. there why that?

so if understand how works, delegates register ones being called on second thread, right? in case, can use thread synchronization in test , delegate gets called. kind of thing in unit tests time.

something this:

[testmethod] [hosttype("moles")] public void adddelegatetoscanner_scanhappens_scandelegateiscalled() {     // arrange     var scancalledevent = new manualresetevent(false);     mcoredll.gettopwindow = () => (new intptr(fauxhandle));      // act     _scanner.adddelegatetoscanner(_formidentity, ((evnt) => { scancalledevent.set(); }));     _scanner.sendscan(new barcodescannereventargs("12345678910"));      // wait event fire     bool scancalledintime = scancalledevent.waitone(some_timeout_in_milliseconds);      // assert     assert.istrue(scancalledintime); } 

it's important have some sort of timeout in there, otherwise if goes wrong test locks , that's kind of hard debug. waitone block until event gets set or timeout expires, return value tells happened.

(warning: may have return value backwards - don't remember off top of head if true means event got set or if true means timeout expired. check docs.)

there several sync primitives can use here, 1 depends on want do. manualresetevent works pretty me.