DivZero Bug Checker

DivZero.java

public class DivZero extends BugChecker
    implements BinaryTreeMatcher, CompoundAssignmentTreeMatcher {

  @Override
  public Description matchBinary(BinaryTree tree, VisitorState state) {
    return matchDivZero(tree, tree.getRightOperand(), state);
  }

  @Override
  public Description matchCompoundAssignment(CompoundAssignmentTree tree, VisitorState state) {
    return matchDivZero(tree, tree.getExpression(), state);
  }

  private Description matchDivZero(Tree tree, ExpressionTree operand, VisitorState state) {
    if (!anyOf(kindIs(Kind.DIVIDE), kindIs(Kind.DIVIDE_ASSIGNMENT)).matches(tree, state)) {
      return Description.NO_MATCH;
    }

    if (!kindIs(Kind.INT_LITERAL).matches(operand, state)) {
      return Description.NO_MATCH;
    }

    LiteralTree rightOperand = (LiteralTree) operand;
    if (((Integer) rightOperand.getValue()) != 0) {
      return Description.NO_MATCH;
    }

    // Find and replace enclosing Statement.
    StatementTree enclosingStmt =
        ASTHelpers.findEnclosingNode(state.getPath(), StatementTree.class);
    return (enclosingStmt != null)
        ? describeMatch(tree,
            SuggestedFix.replace(enclosingStmt, "throw new ArithmeticException(\"/ by zero\");"))
        : describeMatch(tree);
  }
}