Performing an asyncDispatch with MockMvc fails if DeferredResult is not yet set [SPR-13079]

[spring-projects-issues]

Jacek Suchenia opened SPR-13079 and commented

When failing DeferredResult, mockMvc do not populate correct error into response.

In an attached test, both deferred results were failed, but one immediately, and second one after a while - results are different

Tested on 4.2 RC1

Jacek

---

Affects: 4.2 RC1

Attachments:

• SpringDefferedResultTest.java (3.72 kB)

Referenced from: commits spring-projects/spring-boot@d793d5a, spring-projects/spring-boot@6387f36

2 votes, 6 watchers

[spring-projects-issues]

Rossen Stoyanchev commented

In MockMvc there is no Servlet forwarding, and no async dispatches since we are not running in an actual Servlet container. So before performing the asyncDispatch you have to make sure the async result has been computed. Normally this isn't an issue if you add an expectation about the async result, which awaits its computation, but in your test there is no such expectation. Adding it fixes the issue:

MvcResult mvcResult = this.mockMvc.perform(get("/test/async"))
		.andDo(print())
		.andExpect(request().asyncStarted())
		.andExpect(request().asyncResult(instanceOf(RuntimeException.class)))
		.andReturn();

this.mockMvc.perform(asyncDispatch(mvcResult))
		.andDo(print())
		.andExpect(status().is5xxServerError())
		.andExpect(content().string("Internal Server Error: Error"));

[spring-projects-issues]

Rossen Stoyanchev commented

I'm turning this into an improvement since there are a couple of things we can do. One, improve the Javadoc to indicate clearly the DeferredResult must be set before calling asyncDispatch, which can be achieved by adding an expectation, calling MvcResult.getAsyncResult(timeout), or by setting the DeferredResult.

One more thing we could do is actually call getAsyncResult from within asyncDispatch ourselves. It should return immediately if already set.

[spring-projects-issues]

Juergen Hoeller commented

Let's try to sort this out for 4.2 RC2 still...

Juergen

[spring-projects-issues]

Piotr Kubowicz commented

I see the issue was fixed in 6842fd7fb954e751fb6, but maybe it will be worth to add an automated regression test as well - something similar to the attached file?

[spring-projects-issues]

Sam Brannen commented

Piotr Kubowicz, have you signed the SpringSource CLA?

[spring-projects-issues]

Jacek Suchenia commented

Sam Brannen I'm the author of an attached code & I signed ICLA

[spring-projects-issues]

Sam Brannen commented

Jacek Suchenia, thanks for confirming that you've signed the CLA; and Piotr Kubowicz, I apologize for mistaking you for the author of the attached code.

[spring-projects-issues]

Sam Brannen commented

FYI: I have introduced a test based on your example.

See the new deferredResultWithDelayedError() method in AsyncTests.