Part of #13999

(Check Documentation)

Mutation:

Definitions:

1. and-expression:-

ancestor.getType() == TokenTypes.LITERAL_TRY
&& ancestor.findFirstToken(TokenTypes.LITERAL_CATCH) != null	

2. first-operand: ancestor.getType() == TokenTypes.LITERAL_TRY
3. second-operand: ancestor.findFirstToken(TokenTypes.LITERAL_CATCH) != null
4. mutant: replacing first-operand with true.

Why mutant survives:

• mutant does not alters the result of and-expression because LITERAL_CATCH cannot exist without being the child of LITERAL_TRY.
• This makes evaluating first-operand not a necessity because second-operand being evaluated as true implicitly means that the type of ancestor is LITERAL_TRY.

Why mutant cannot be killed:

• For this, there needs to be an input where LITERAL_CATCH exist without a preceding LITERAL_TRY block
• This results in compilation error and hence is not possible.

Why not remove second-operand:

• The and-expression is meant to evaluate if the throw is inside a try block which has a corresponding catch block.
• Unlike catch block, which cannot exist without a try block, try block can exist without a catch block.

⚠️ Performance Impact:

• Benefit due to short circuiting in and-expression should be weighed in before merging this PR.
• If ancestor is not LITERAL_TRY, findFirstToken() is not only useless for the reason that it won't find a LITERAL_CATCH ;
• But along with that, it may impact performance if ancestor has a significant number of children.
• This is avoided by short circuiting in and-expression but results in the surviving mutant.

Change:

Updated the code as Pitest mutated, except it is now the last operand of the or-statement to help mitigate the performance impact by a bit.
(Although this shifting of operands may produce negligible performance gains, still better than none)

Usage:

Definition and the only usage for the method with mutant is in JavadocMethodCheck. (1 usage)
JavadocMethodCheck does not affect any other class.
Call Stack:

isInIgnoreBlock:691, JavadocMethodCheck (com.puppycrawl.tools.checkstyle.checks.javadoc)
  getThrowed:640, JavadocMethodCheck (com.puppycrawl.tools.checkstyle.checks.javadoc)
    checkComment:442, JavadocMethodCheck (com.puppycrawl.tools.checkstyle.checks.javadoc)
      processAST:392, JavadocMethodCheck (com.puppycrawl.tools.checkstyle.checks.javadoc)
        visitToken:374, JavadocMethodCheck (com.puppycrawl.tools.checkstyle.checks.javadoc)
          notifyVisit:335, TreeWalker (com.puppycrawl.tools.checkstyle)
            processIter:408, TreeWalker (com.puppycrawl.tools.checkstyle)
              ...

Regression:

Result: No differences found. (Report)

Diff Regression config: https://gist.githubusercontent.com/sktpy/44a31ea4e946a0755fa3e331fd65de98/raw/233b4d68f7cd46f957ee37e94813922d5fd1733c/check.xml

Diff Regression projects: https://gist.githubusercontent.com/sktpy/49239940660ceaef88d224d6abc8878e/raw/058cbb1b662c9276e934fdffbb99cec760332398/projects-to-test-on.properties