Truncate excessively large log output in large collections

[mdedetrich]

About this change - What it does

Overrides the default scalatest prettifier to one that truncates in the case of having excessively large collections

Why this way

Currently we have the issue where if one of the S3 tests fails then it creates an excessively large test output (example https://github.com/aiven/guardian-for-apache-kafka/runs/7500976439?check_suite_focus=true) due to the fact that we create very large collections (i.e. many megs in size). Overridding the prettifier with Prettifier.truncateAt allows to limit the size of the collection.

Note that scalatest will still print the initial seed that caused a failure so its still possible to recreate the test scenario without having to see the generated dataset.

[coveralls]

Pull Request Test Coverage Report for Build 3156846522

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage remained the same at 75.844%

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Files with Coverage Reduction	New Missed Lines	%
core-s3/src/main/scala/io/aiven/guardian/kafka/s3/Config.scala	1	82.98%

Totals
Change from base Build 3138762884:	0.0%
Covered Lines:	292
Relevant Lines:	385

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💛 - Coveralls

[mdedetrich]

While using Prettifier.truncateAt is the correct change for the problem, unfortunately the current implementation of Prettifier.truncateAt doesn't work if the generated collections are inside a case class. PR has been submitted upstream at scalatest/scalatest#2155 to solve the issue.

[mdedetrich]

PR is now ready to review since new scalatest has been released fixing the problem mentioned at #265 (comment) (see scalatest/scalatest#2155 (comment)).

You can see a result of the truncation here when I deliberately make a test fail.

TestFailedException was thrown during property evaluation.
  Message: The future returned an exception of type: io.aiven.guardian.kafka.s3.S3Spec$DownloadNotReady, with message: Download not ready, current state is .
  Location: (RealS3BackupClientSpec.scala:142)
  Occurred when passed generated values (
    arg0 = KafkaDataInChunksWithTimePeriod(List(List(ReducedConsumerRecord(lQj-.3y_-q.6-_4.7G.0-.x_-.j.--.0O_-9-_.3S-171_-8-_Fs.5_.7_-_.e.r..3-ub_9.-24.j__-4__.m.O1.48.._._-.n--.U.74_M6.m7-8_7-L_f.2p-k.Z._Z_T_.-_._F-.._2_5.22_p,0,0,Some(bA==),bkNRbHJYTnZQanZtY1JWd1dDZkJpRnNjamt3THJQSERzTWNJb1JFV3lGaGlTcnduWGdJWExPbQ==,1,CreateTime), ReducedConsumerRecord(lQj-.3y_-q.6-_4.7G.0-.x_-.j.--.0O_-9-_.3S-171_-8-_Fs.5_.7_-_.e.r..3-ub_9.-24.j__-4__.m.O1.48.._._-.n--.U.74_M6.m7-8_7-L_f.2p-k.Z._Z_T_.-_._F-.._2_5.22_p,0,1,Some(bA==),emtDbGlsenlheFBRc2duSHZLWGJLU1R2VFJabUVDVURCbw==,3,CreateTime), ReducedConsumerRecord(lQj-.3y_-q.6-_4.7G.0-.x_-.j.--.0O_-9-_.3S-171_-8-_Fs.5_.7_-_.e.r..3-ub_9.-24.j__-4_<...>ducedConsumerRecord(Mx5.K-7--F.4a_-.-8-D.-K.-2_.t-..3.pR6-.._d--G-..0.1A-1f_-x.L8-....-2pN3._A2_._V.,0,7046,Some(Rw==),b3JUQllKa1BXdVdHdUNaR1pnVVFxcXhxQld5RGhlUlVNSFZmdVVEaQ==,34263,CreateTime), ReducedConsumerRecord(Mx5.K-7--F.4a_-.-8-D.-K.-2_.t-..3.pR6-.._d--G-..0.1A-1f_-x.L8-....-2pN3._A2_._V.,0,7047,Some(Rw==),ek9jbGxBTk1vc3JlcU94cFVIc2NOTGRQZWxFWVlJTENkRVJqeVZGbXpkWnl2WGFITVZGTkRLUlVpUm5lZU5oUmRXV2N3dFVFcGxrQnRwdA==,34266,CreateTime), ReducedConsumerRecord(Mx5.K-7--F.4a_-.-8-D.-K.-2_.t-..3.pR6-.._d--G-..0.1A-1f_-x.L8-....-2pN3._A2_._V.,0,7048,Some(Rw==),dw==,34267,CreateTime))),34268 milliseconds),
    arg1 = S3(guardian-gepzrk2-glrmd2tnumltte-hxnagmzxjger9yd4,None,RestartSettings(minBackoff=5 milliseconds,maxBackoff=10 seconds,randomFactor=0.2,maxRestarts=2147483647,maxRestartsWithin=5 milliseconds)),
    arg2 = "" // 2 shrinks
  )
Init Seed: 1907363718961213527