test: add regression tests for LIKE operator backtracking (#409) - #449
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Issue alibaba#409 reported that v3's OperatorLike.matchPattern used a greedy segment-matching algorithm without backtracking, causing patterns like "a%c" on input "abc" to incorrectly return false. v4 fixed this with a proper backtracking algorithm using sRecall/pRecall pointers in BaseBinaryOperator.matchPattern. However, no regression tests existed for these backtracking edge cases. This commit adds: - Issue409RegressionTest.java: 14 JUnit tests covering backtracking, multi-wildcard, trailing/leading %, empty strings, null handling, and conditional expressions - like.ql: 14 additional QL assertions for backtracking scenarios 🤖 Generated with [Qoder][https://qoder.com]
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Summary
Issue #409 reported that v3's
OperatorLike.matchPatternused a greedy segment-matching algorithm without backtracking, causing patterns like"abc" like "a%c"to incorrectly returnfalse.v4 fixed this by replacing the greedy algorithm with a proper backtracking matcher using
sRecall/pRecallpointers inBaseBinaryOperator.matchPattern. However, no regression tests existed for these backtracking edge cases.This PR adds comprehensive regression tests to prevent the v3 bug from silently regressing.
Changes
New file:
src/test/java/.../issue/Issue409RegressionTest.java14 JUnit tests organized by category:
"abc" like "a%c", variable-based"aXbYc" like "a%b%c", repeated prefix%"1%1" like "1%","%6""" like "%","" like "%%""abc" like "a%d","%x%"not_likeinversenot_likeis exact inversenull like null,"a" like nullifand with&&Updated:
src/test/resources/.../operator/like.ql14 additional QL-level assertions covering backtracking, multi-wildcard, trailing
%, and negative cases.Why This Matters
The v3 bug was subtle — it only manifests when the greedy first-match of a wildcard segment is suboptimal. The existing test
"ABCD" like "A%B%D"passes even with the buggy v3 algorithm because each segment's first occurrence happens to be the correct one. Without explicit backtracking tests, a future refactor could reintroduce the bug undetected.Fixes #409