Fix handling unsupported compression codec (#795)

[ods]

Changes

Fixes #795

Checklist

• I think the code is well written
• Unit tests for the changes exist
• Documentation reflects the changes
• Add a new news fragment into the CHANGES folder

[codecov]

Codecov Report

Merging #798 (0a5b0ba) into master (fcee7d1) will decrease coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #798      +/-   ##
==========================================
- Coverage   97.89%   97.87%   -0.03%     
==========================================
  Files          31       31              
  Lines        5279     5307      +28     
==========================================
+ Hits         5168     5194      +26     
- Misses        111      113       +2     

Flag	Coverage Δ
cext	88.58% <25.00%> (-0.36%)	⬇️
integration	97.83% <100.00%> (-0.03%)	⬇️
purepy	97.39% <100.00%> (-0.03%)	⬇️
unit	51.89% <100.00%> (+0.27%)	⬆️

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Impacted Files	Coverage Δ
aiokafka/errors.py	100.00% <ø> (ø)
aiokafka/record/default_records.py	96.01% <100.00%> (+0.15%)	⬆️
aiokafka/record/legacy_records.py	98.97% <100.00%> (+0.05%)	⬆️
aiokafka/consumer/fetcher.py	96.87% <0.00%> (-0.32%)	⬇️

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[lgtm-com]

This pull request introduces 2 alerts when merging 6483a3d into fcee7d1 - view on LGTM.com

new alerts:

• 2 for Module is imported with 'import' and 'import from'

[lgtm-com]

This pull request introduces 2 alerts when merging 0a5b0ba into fcee7d1 - view on LGTM.com

new alerts:

• 2 for Module is imported with 'import' and 'import from'

[tvoinarovskyi]

Can we reuse the same function to avoid copy-paste?

[ods]

Sure. What module is the best place to put in?

[ods]

Oh, sorry. They will diverge after adding zstd support. I think that's the reason why it's duplicated in kafka-python: legacy record can't be used with zstd compression. But I didn't verified this, so the difference may be a mistake too.

[ods]

According to KIP-110

Zstd will only be allowed with magic = 2 format

[tvoinarovskyi]

I see, let's see how it looks with zstd I guess.