Unit testing addError without doing DML

Question

We're big fans of doing unit tests using as little DML as possible, mocking SObjects using various techniques

Here's a simple example

public class FoosService {
 public void doBar(Set<Id> ids) {
  ... do work ...
  ... oops ... throw BarException
 }
}

public class FoosDomain {

 public void onAfterInsert(SObject[] records) {
    try {
      FooService.doBar(new Map<Id,SObject>(records).keySet();
    }
    catch (FoosService.BarException e) {
      // apply addError(e) to relevant rows in records 
    }
 }
} 

In the unit testmethod:

Foo__c[] mockFoos = new List<Foo__c> {
  new Foo__c(...),
  new Foo__c(...)  // causes exception in FoosService.doBar
};
new FoosDomain.onAfterInsert(mockFoos);

you want to be able to do this:

System.assertEquals(true,mockFoos[1].hasError(),'sb marked as error');

but there is no SObject method to see if a given SObject has had addError(...) applied to it.

Known workarounds:

fflib-apex-common fflib_SObjectDomain class which supports this testable construction:

someSobject.addError(error('message',someSobject));

System.assertEquals('message',
    fflib_SObjectDomain.Errors.getAll()[1].message);

and as we're an fflib shop, I'm happy to use this

Is there some other "trick" I don't know about to discover in an assert that a non-DML'd SObject has had addError applied?

Answer 1

Yes. Weirdly enough, ApexPages.hasMessages() returns true when any record has had addError called on it.

Account record = new Account();
record.addError('Some message');
system.assert(ApexPages.hasMessages(), 'Informative message');

You won't be able to test which records have hit a validation, but you can tell if any have. Design your tests accordingly.

Answer 2

In V50, Apex SObject class now has two new useful methods to solve this issue

• Boolean hasErrors()
• Database.Error[] getErrors()