feat(tdigest): add TDIGEST.MAX/MIN command

[wyxxxcat]

This closes #2793.

PR Overview

This PR adds tests for the new TDIGEST.MAX and TDIGEST.MIN commands to validate their behavior, including error handling and correct value computation.

• Introduces the error message constant errValueDoesNotExist for cases where a tdigest exists but contains no data.
• Adds subtests for both TDIGEST.MAX and TDIGEST.MIN covering invalid arguments, empty digests, and digests with one or multiple values.

Reviewed Changes

File	Description
tests/gocase/unit/type/tdigest/tdigest_test.go	Added tests to cover TDIGEST.MAX and TDIGEST.MIN functionality

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (2)

tests/gocase/unit/type/tdigest/tdigest_test.go:217

• [nitpick] Consider reinitializing the tdigest or using a fresh key when transitioning from testing a single value to multiple values. This ensures that previous state does not affect the aggregation and makes each test case more isolated.

require.NoError(t, rdb.Do(ctx, "TDIGEST.CREATE", key, "compression", "100").Err())

tests/gocase/unit/type/tdigest/tdigest_test.go:212

• [nitpick] Consider expanding the invalid argument tests by including cases with extra arguments for both TDIGEST.MAX and TDIGEST.MIN to further improve test coverage.

require.ErrorContains(t, rdb.Do(ctx, "TDIGEST.MAX").Err(), errMsgWrongNumberArg)

PR Overview

This PR adds tests for the new TDIGEST.MAX and TDIGEST.MIN commands to ensure their correct behavior with various arguments.

• Added a new error constant for missing values.
• Introduced test cases for TDIGEST.MAX and TDIGEST.MIN covering invalid arguments, empty digests, and digests with one or multiple values.

Reviewed Changes

File	Description
tests/gocase/unit/type/tdigest/tdigest_test.go	Added tests for TDIGEST.MAX and TDIGEST.MIN commands and a new error constant

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

tests/gocase/unit/type/tdigest/tdigest_test.go:39

• [nitpick] Consider renaming 'errValueDoesNotExist' to 'errMsgValueDoesNotExist' for consistency with the other error constants defined in this file.

errValueDoesNotExist   = "no value exists for key"

[mapleFU]

Code general LGTM, but suddenly I realized that TDigest.Add nan is invalid: https://github.com/RedisBloom/RedisBloom/blob/f68a72e463b84c2298990295c6a3db4719dc5c7a/src/rm_tdigest.c#L187

Would you mind also change that? ( Can be in another pr )

[wyxxxcat]

Code general LGTM, but suddenly I realized that TDigest.Add nan is invalid: https://github.com/RedisBloom/RedisBloom/blob/f68a72e463b84c2298990295c6a3db4719dc5c7a/src/rm_tdigest.c#L187

Would you mind also change that? ( Can be in another pr )

I will fix

[mapleFU]

By the way would you mind extract an:

struct MinMax {
   min, max
};
class CommandTDigestMinMaxImpl {
   StatusOr<MinMax> Execute(...)
};

? I just think this could eliminate some code

[wyxxxcat]

yes！I will pick it

[sonarqubecloud]

Quality Gate failed

Failed conditions
34.4% Duplication on New Code (required ≤ 20%)

See analysis details on SonarQube Cloud