Unit tests

[fzs]

Have you ever considered adding unit tests to the project?
I am reading the code and since I do not have the most in-depth mDNS knowledge I have a hard time understanding what some parts of the code do. So aside from helping with refactoring the code, unit tests could also be helpful to understand what certain code is supposed to do.

[troglobit]

Yes, I've planned it ever sine I had a breakthrough in some of my other projects using unshare(1). Let me see what I can whip up later today, shouldn't be too much work to get some basics up and running :)

Again, sorry for missing all this (and the PRs). Seems my project notifications were out of whack on GitHub for some reason.

[troglobit]

Ah ... that's probably it. We're mixing apples and oranges -- tests both in C and .sh, with and without ending. Good find! I had a feeling this was going to bite us. Maybe we can play around with dropping the .sh from shell scripts (and the TEST_EXTENSIONS)? At least to test the theory.

[fzs]

I can try that a bit later. But why does it still work for you but not on my systems?

[troglobit]

Good question, and I don't know what I was smoking earlier (or what state my clone was in), but I no longer get make check TESTS=discover.sh to work either -- so that's progress I guess, we now both have the same issue 😁

[fzs]

I played around with removing TEST_EXTENSIONS and renaming the scripts but could not get it to work.

[troglobit]

Thank you for giving it a go! I just created issue #66 for this.

[fzs]

Have you ever considered actual unit tests?
I am intrigued by your setup with unshare, I will have to learn more about it and an learn to use it.
But I also see value in actual unit tests, while the current ones are more integration tests. They require a Linux system and the mdnsd and mquery binaries (and are also a bit testing my code with my code). We integrate mdnsd into a non-linux embedded OS, so it is not a 1-to-1 mapping. We are mostly using cmocka for unit tests, and currently have tests for mdnsd external to the source tree. I wonder if it would be of value and interest to integrate them with the project. It does add a dependency on the test suite library, though.
I also sometimes find it easier to test with smaller unit tests during development, like for example when implementing complexer checks for link-local, site-local. global addresses replacing each other.

[troglobit]

Adding actual unit tests to an existing program/library is a LOT of work. I've considered it in the past but I have not had much time to spend on this low-prio project lately.

You are much welcome to add unit tests with cmocka if you feel up to it! I can help out with adding configure flags to run only unit tests and disable component tests, if you like? I do prefer having it all in the same test/ sub-directory so a regular build with "make check" runs everything.

[fzs]

I would need some help adding the dependency on the cmocka library to the Makefiles, as I have no experience with autotools.
I would suggest adding a src directory under test and put test source code files there.

[troglobit]

I've just pushed initial support, including a bare bones example, to master in cda3cb4. Hope it helps :)

Not sure if the src subdirectory should hold run the tests, or if we should run them together from the parent test directory. You try it out and tell me what you think.

[fzs]

Excellent!
Two questions:
When testing addr.c or conf.c, how can I link these into the test binary?
Is there a way to add linker flags (-Wl --wrap=something) for certain noinst_PROGRAMS?

I should add that I toyed around with LDADD and LDFLAGS but I have no idea if this is the correct way to do it.

addr_LDADD   = ../../src/addr.o $(LIBOBJS)
addr_LDFLAGS = $(AM_LDFLAGS) -Wl,--wrap=getifaddrs

[troglobit]

Yup, that's the correct way to do it. You can also set it globally for all test binaries with the AM_foo variables. And if you want test specific flags you need to do it like you did in your example, because the AM_foo variables are not included if there are test specific ones declared.

[troglobit]

@fzs heads-up, I've just pushed a few changes to the test/ directory to address issues with make distcheck. Not sure if that fixes your above issues with make check as well ...