Using an undefinied accumulate function should give a clear error warning instead of a NullPointerException ----------------------------------------------------------------------------------------------------------- Key: JBRULES-2419 URL: https://jira.jboss.org/jira/browse/JBRULES-2419 Project: Drools Issue Type: Bug Security Level: Public (Everyone can see) Components: drools-compiler (expert) Affects Versions: 5.0.1.FINAL Reporter: Geoffrey De Smet Assignee: Edson Tirelli Priority: Minor Reproduced on with Micheals project with Drools 5.0.1 I got this error: {code} Exception caught while executing action: org.drools.reteoo.ReteooWorkingMemory$WorkingMemoryReteAssertAction@1a5e68a java.lang.NullPointerException at org.drools.base.accumulators.JavaAccumulatorFunctionExecutor.createContext(JavaAccumulatorFunctionExecutor.java:82) at org.drools.rule.Accumulate.createContext(Accumulate.java:122) {code} when I wrote this rule for him: {code} rule "rewardLowestNonFree" when $lowestAppsSize : Number() from accumulate( AppServerInstance(apps.size != 0, $appsSize : apps.size), lowest($appsSize) // Vote for http://jira.jboss.com/jira/browse/JBRULES-1075 ); then insertLogical(new IntConstraintOccurrence("rewardLowestNonFree", ConstraintType.POSITIVE, - $lowestAppsSize.intValue())); end {code} Turns out the "lowest" function doesn't exist. (I should have used "min" btw) -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira