Make Sparkey testable

[kellen]

Adds SparkeyIO, a TestIO (rather than full-fledged ScioIO). Deprecates sideinput map.

Suggestions around naming the output Sparkey IO, currently SparkeyIO.output[K, V], are welcome as this feels awkward. An alternative is to use SparkeyIOOutput[K, V] directly, but this is also ugly.

Instead of #3172

Fixes #3173
Fixes #4819

[codecov]

Codecov Report

Attention: 37 lines in your changes are missing coverage. Please review.

Comparison is base (11ed971) 63.34% compared to head (b011c4f) 63.42%.
Report is 6 commits behind head on main.

❗ Current head b011c4f differs from pull request most recent head 300958a. Consider uploading reports for the commit 300958a to get more accurate results

Files	Patch %	Lines
...io/extra/sparkey/instances/MockSparkeyReader.scala	16.12%	26 Missing ⚠️
...scala/com/spotify/scio/extra/sparkey/package.scala	80.95%	8 Missing ⚠️
...ala/com/spotify/scio/extra/sparkey/SparkeyIO.scala	94.91%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5128      +/-   ##
==========================================
+ Coverage   63.34%   63.42%   +0.08%     
==========================================
  Files         291      293       +2     
  Lines       10837    10902      +65     
  Branches      753      716      -37     
==========================================
+ Hits         6865     6915      +50     
- Misses       3972     3987      +15     

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[clairemcginty]

can we include a deprecation message advising users what methods to use instead?

[kellen]

No this is just a pure "don't do this"

[RustedBones]

Can we instead have SparkeyIO expect a Map[K, V] (or Seq[(K, V)]) instead of a reader ? We would create the reader in the IO after isTest is checked.

[kellen]

I tried this initially; the type parameter on ScioIO has to match the type of the mock data iterable passed to input, then in the internals of JobTest the SCollection returned must also be of the same type, so without changing the contract of ScioIO I don't think this is possible