Fidlib Unit-Tests

[daschuer]

This adds two tests, that aims to detect bugs like #11483

This is one step closer to the source, compared to #11489 and can be a low impact alternative. We may consider to close the outer test PR or keep/tweak it to be an extension to this one.

[daschuer]

@uklotzde @hapst3r can you check if these test are failing with GCC 13?

[Swiftb0y]

GCC 13.0.1

Note: Google Test filter = EngineFilterBiquadTest.*
[==========] Running 4 tests from 1 test suite.
[----------] Global test environment set-up.
[----------] 4 tests from EngineFilterBiquadTest
[ RUN      ] EngineFilterBiquadTest.fidlibInputRespectsLocale
[       OK ] EngineFilterBiquadTest.fidlibInputRespectsLocale (0 ms)
[ RUN      ] EngineFilterBiquadTest.fidspecLengthIsLongEnough
[       OK ] EngineFilterBiquadTest.fidspecLengthIsLongEnough (0 ms)
[ RUN      ] EngineFilterBiquadTest.analysisPkBq
[       OK ] EngineFilterBiquadTest.analysisPkBq (0 ms)
[ RUN      ] EngineFilterBiquadTest.analysisLpBe4
/home/swiftb0y/Sourcerepositories/mixxx/src/test/enginefilterbiquadtest.cpp:41: Failure
Expected equality of these values:
  delay
    Which is: 22
  24
[  FAILED  ] EngineFilterBiquadTest.analysisLpBe4 (0 ms)
[----------] 4 tests from EngineFilterBiquadTest (0 ms total)

[----------] Global test environment tear-down
[==========] 4 tests from 1 test suite ran. (0 ms total)
[  PASSED  ] 3 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] EngineFilterBiquadTest.analysisLpBe4

[uklotzde]

Confirmed. Test is failing as expected.

[Swiftb0y]

LGTM otherwise.

[Swiftb0y]

phase0 could be uninitialized on failure and might be 0 implicitly. Can we initialize to some placeholder value? same applies to analysisLpBe4.

[daschuer]

Done.

[Swiftb0y]

LGTM, though I can't judge how robust these tests are actually are.