Refine upper bound for startsWith/endsWith

[shubhamk0205]

solves #5201

previously , code checked if (methodName.startsWith(prefix)) we know by intuition that prefix length is less than or equal to method length . but the checker doesnt know this and gives us a false warning .
to solve this when the code calls this method and returns true , then our code tells checker that prefix length is less or equal to the method length and doesnt give us warning .
also i have removed suppress warning annotation .

[coderabbitai]

📝 Walkthrough

Walkthrough

Adds cached lookups for three String methods as private fields initialized in the constructor via TreeUtils and imports ExpressionTree, ExecutableElement, and TreeUtils. Overrides processConditionalPostconditions to handle String.startsWith(String) and String.endsWith(String): when receiver and argument are resolvable, creates a LessThanLengthOf qualifier (offset -1) for the receiver and, if insertable, inserts a corresponding refinement for argument.length() into the then-branch CFStore while still calling super. Tests add endsWith-based cases, remove a prior suppression, and add negative tests. Docs update the contributors list with additional names.

🚥 Pre-merge checks | ✅ 1

✅ Passed checks (1 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	Docstring coverage is 87.50% which is sufficient. The required threshold is 80.00%.

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✨ Finishing touches

• 📝 Generate docstrings

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[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In
`@checker/src/main/java/org/checkerframework/checker/index/upperbound/UpperBoundTransfer.java`:
- Around line 754-796: The code unconditionally calls
thenStore.insertValue(argLengthExpr, anno) inside
processConditionalPostconditions for startsWith/endsWith; guard this with
CFAbstractStore.canInsertJavaExpression(argLengthExpr) (same pattern used in
visitLengthAccess) so you only call thenStore.insertValue(...) when
canInsertJavaExpression(argLengthExpr) returns true, preserving existing checks
(unknowns/determinism) and avoiding attempts to insert non-insertable
expressions.

[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@docs/manual/contributors.tex`:
- Around line 154-155: The contributor list has "Zhiping Cai, shubhamk0205." out
of alphabetical order; move the "shubhamk0205" entry from the end into the
correct alphabetized position among the other "Shubham …" contributors (so the
list remains alphabetically ordered) and ensure punctuation/spacing
(comma/period) matches the surrounding entries (e.g., keep the trailing period
only at the end of the full list).

[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@checker/tests/index/StartsEndsWith.java`:
- Around line 30-40: The comment above removeSuffix should be expanded to
clearly state this test intentionally demonstrates a checker limitation:
although endsWith(suffix) implies suffix.length() <= methodName.length(), the
checker cannot prove the arithmetic upper bound used in methodName.substring(0,
methodName.length() - suffix.length()), so the test expects an error; update the
comment to state that this is a known limitation test for arithmetic expression
refinement and mention the targeted expression (methodName.length() -
suffix.length()) and the expected diagnostic on the substring call.

♻️ Duplicate comments (1)

docs/manual/contributors.tex (1)

154-156: Alphabetical order is broken and duplicate entry exists.

"Shubham Kapoor" should be inserted alphabetically near line 134 (after "Shubham Raj" or before "Sidney Monteiro"). Also, "shubhamk0205" appears to be a GitHub handle—if this is the same person as "Shubham Kapoor," only one entry is needed. If they are different contributors, "shubhamk0205" should also be placed alphabetically (or converted to a real name for consistency with the rest of the list).

[shubhamk0205]

@mernst the fix causes @SuppressWarnings("index:argument") in plume-util's StringsPlume.java:64 to become unnecessary, triggering an unneeded.suppression warning. This is expected behavior since we fixed the false positive. according to me the plume-util library should remove this suppression since it is not needed after this pr get merged

[mernst]

Please

• create a fork of plume-util
• create a branch with exactly the same name as this one (fix-startswith-refinement-5201)
• make your proposed change on that branch
• push it
• open a PR for it
• write "merge with <reference to that PR>" to the description description at the top of this pull request

Now, CI for this pull request will use it and should no longer fail.
You need to trigger a re-run of the failing CI job; if you are not allowed to do so, you can either push a trivial change or ask me to do it.

Thanks.