Add null guard for AddCommentToMethod and NumberToDuration

[davidh44]

Motivation and Context

When OpenRewrite scans the classpath for recipes, it discovers and instantiates all recipe classes, including ones that are only meant to be used as sub-recipes with YAML-provided options (e.g., methodPattern). These bare instances are created with null fields since no options are provided during classpath scanning.

In newer OpenRewrite versions, the rewritten MethodMatcher parser no longer tolerates null patterns, causing NullPointerException when these bare instances are invoked during recipe execution.

This affects recipes that use AddCommentToMethod and NumberToDuration, which are configured via YAML in change-config-types.yml and change-exception-types.yml.

This issue occurs when recipes are loaded via OpenRewrite's ClasspathScanningLoader (e.g., when running recipes from a standalone jar). It does not affect the Maven or Gradle plugin paths, which handle recipe instantiation differently.

Modifications

Added null check in getVisitor() for AddCommentToMethod and NumberToDuration - returns TreeVisitor.noop() when methodPattern is null. YAML-configured instances with actual method patterns are unaffected.

Testing

Tested locally, NPE disappears

License

• I confirm that this pull request can be released under the Apache 2 license

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
66.7% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

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