Fix to work with Bleak on a mac

[finik]

• Sometimes the data returnes is not byte/bytes, but native objective-c class _NSInlineData
  even though isinstance will fail, otherwise it seems to be working

[codecov-commenter]

Codecov Report

Merging #78 into master will decrease coverage by 0.65%.
The diff coverage is 72.50%.

@@            Coverage Diff             @@
##           master      #78      +/-   ##
==========================================
- Coverage   75.76%   75.11%   -0.66%     
==========================================
  Files          18       20       +2     
  Lines        2080     2270     +190     
==========================================
+ Hits         1576     1705     +129     
- Misses        504      565      +61     

Impacted Files	Coverage Δ
pylgbst/comms/cgattlib.py	0.00% <0.00%> (ø)
setup.py	0.00% <ø> (ø)
pylgbst/comms/cbluepy.py	67.81% <25.00%> (ø)
pylgbst/comms/cgatt.py	42.55% <50.00%> (-2.13%)	⬇️
pylgbst/comms/cbleak.py	51.96% <51.96%> (ø)
pylgbst/__init__.py	34.09% <62.50%> (+6.59%)	⬆️
pylgbst/hub.py	93.00% <84.61%> (-1.71%)	⬇️
pylgbst/peripherals.py	75.72% <95.65%> (+0.26%)	⬆️
tests/test_cbleak.py	97.82% <97.82%> (ø)
pylgbst/comms/__init__.py	38.31% <100.00%> (+1.22%)	⬆️
... and 13 more

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[undera]

Thanks for your investigations!

I think the fix should be slightly modified, though. Instead of modifying generic parts of the library, the fix should be local to cbleak.py. Speficially around this line: https://github.com/undera/pylgbst/blob/master/pylgbst/comms/cbleak.py#L81

The reason is that generic part of lib assumes certain data types for payloads, and we should not let any implementation-specific type to slip into. So doing type conversion on msg[1] prior to calling self._handler(msg[0], msg[1]) should be the right way of fixing.

Again, I myself don't have Mac to validate this, so relying on you here...

[finik]

I agree, I tried it but it didn't work, but there must be a way to copy bytes from _NSInlineData into real bytes and pass it over, I will clean it up

[undera]

Overall this looks like a bug in Bleak itself, that it leaks internal _NSInlineData class into notification function

[undera]

This might be a pointer to a solution: https://github.com/Charliealver/bleak/pull/1/files#diff-8f13c6112bf9c88568af14b21a928142R183

[finik]

any objections?

[undera]

All is good, thanks

[finik]

btw I don't have time to test, but it looks like the second version of the fix, which actually translated it into bytes just magically fixed all the instability issues we had before.