[Backport 2.x] Fix truncate() function

[opensearch-trigger-bot]

Backport 7714819 from #1197

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.83%. Comparing base (753847b) to head (e14cca1).
⚠️ Report is 445 commits behind head on 2.x.

❌ Your project status has failed because the head coverage (95.83%) is below the target coverage (99.00%). You can increase the head coverage or adjust the target coverage.

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x    #1213      +/-   ##
============================================
- Coverage     98.32%   95.83%   -2.49%     
  Complexity     3552     3552              
============================================
  Files           346      356      +10     
  Lines          8757     9415     +658     
  Branches        554      673     +119     
============================================
+ Hits           8610     9023     +413     
- Misses          142      334     +192     
- Partials          5       58      +53     

Flag	Coverage Δ
query-workbench	62.76% <ø> (?)
sql-engine	98.32% <100.00%> (ø)

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