Yet Another Salesforce Tech Blog

• System.debug statements contribute to longer transactions and consume Apex CPU time even when debug logs are not being captured.
• If you are passing complex datatype parameters to System.debug then they will consume more resources, as they will be converted to strings
• Read full blog post here (2021-05): The Impact of System.debug
• Static code analysis tool Apex PMD is also performing this validation
  • https://pmd.github.io/latest/pmd_rules_apex_performance.html

Helper class to conditionally call System.debug

• This pattern uses helper class to have a single place which calls System.debug
  • All other Apex classes should call helper class instead of System.debug to improve production org performance
  • Easiest way is to find and replace System.debug with LogHelper.debug across the whole org codebase
• Helper class checks if the user have custom permission SystemDebugStatementsEnabled set either via profile or permission set with the built-in FeatureManagement class
• System.debug is called by default when running the tests
  • Optionally one could mark static variable debugStatementsEnabled as @TestVisible so that certain test class will activate debugging when needed

public class LogHelper {
	private static Boolean debugStatementsEnabled = FeatureManagement.checkPermission('SystemDebugStatementsEnabled');
	public static void log(System.LoggingLevel level, Object data) {
		if (debugStatementsEnabled || Test.isRunningTest()) {
			System.debug(level, data);
		}
	}
	public static void debug(Object data) {
		log(LoggingLevel.DEBUG, data);
	}
}

Post originally written by Leo Jokinen (Fluido)