Fixed ResultSetReader inconsistency

[alex268]

No description provided.

[Copilot]

Pull request overview

This PR standardizes ResultSetReader positioning/error semantics (before-first/after-last behavior, index validation, and error messages) and updates tests in both table and query modules to reflect the corrected behavior.

Changes:

• Tighten ProtoResultSetReader row positioning semantics and add consistent bounds/state checks with stable exception messages.
• Expand/adjust unit tests for column metadata, iteration, and truncated-result behavior.
• Update composite result set behavior in QueryReader tests and implementation to use setRowIndex(-1) as the reset-to-before-first convention.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
table/src/test/java/tech/ydb/table/result/ResultSetReaderTest.java	Adds comprehensive tests for column metadata, positioning rules, and truncation flag.
table/src/main/java/tech/ydb/table/result/impl/ProtoValueReaders.java	Deprecates forResultSets(...).
table/src/main/java/tech/ydb/table/result/impl/ProtoResultSetReader.java	Fixes positioning logic and adds consistent argument/state validation + messages.
table/src/main/java/tech/ydb/table/result/ResultSetReader.java	Updates/expands API documentation (needs minor corrections/clarification).
query/src/test/java/tech/ydb/query/tools/QueryReaderTest.java	Updates composite result set tests to match new positioning semantics.
query/src/main/java/tech/ydb/query/tools/QueryReader.java	Updates composite setRowIndex reset/position behavior (introduces edge-case bugs for empty/out-of-range).

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 97.72727% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 65.90%. Comparing base (e1721e3) to head (65ea646).
⚠️ Report is 9 commits behind head on release_v2.4.0.

Files with missing lines	Patch %	Lines
...ch/ydb/table/result/impl/ProtoResultSetReader.java	97.22%	1 Missing ⚠️

Additional details and impacted files

@@                 Coverage Diff                  @@
##             release_v2.4.0     #588      +/-   ##
====================================================
+ Coverage             65.16%   65.90%   +0.73%     
- Complexity             2734     2845     +111     
====================================================
  Files                   344      344              
  Lines                 14323    14412      +89     
  Branches               1481     1488       +7     
====================================================
+ Hits                   9334     9498     +164     
+ Misses                 4322     4252      -70     
+ Partials                667      662       -5     

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