Trigger addError on before, will not pass my test class

Question

I have created a trigger on Opportunity and managed to test it and it ran smoothly and even tried it out on the sandbox and everything ran fine. I then decided to use addError() along with the trigger.

if(Trigger.isBefore){   // Error checking, will verify that a contract child does not exist, will also verify that if any variables are null. 
    for(Opportunity verifyOpp: oppsFromDB){             
      if(verifyOpp.service_Contracts__r.size() != 0)
      {
         String x = 'Hi';
         trigger.newMap.get(verifyOpp.Id).addError(x);
      }
    }
   .....

The exception error I get is : System.DmlException: Update failed. First exception on row 0 with id 006.....; first error: FIELD_CUSTOM_VALIDATION_EXCEPTION, HI:[]

Just an FYI the List I am doing a for loop works perfectly fine on the Trigger.isAfter bit, so I am pretty certain it isn't in the eternal loop.

Any help would be greatly appreciated.

Answer 1

This is the appropriate behavior, since you are adding an error to the record. In your test class you need to add the insert within a try/catch statement, and add in assertion in the catch statement verifying the error message received is the error message you passed in.

Hope this helps!