Category Archives: apex mocks

ApexMocks, Selectors, and Formula Fields

This is part 3 of a series, see Part 1 and Part 2

If you’ve bought into mocking Sobjects for use in Unit Tests, you probably have run into the roadblock wherein formula fields and system audit fields can’t be created in SObjects. For example, these won’t compile:

 Account acct = new Account(LastModifiedDate = System.now(), Name = 'Foo');

 Opportunity oppo = new Opportunity(HasLineItems = true, ...);

An example
So, if you have a class method-under-test that wants to do work on Account Opportunities and the work varies based on the value of Opportunity.FormulaField__c

public void doSomeWork(set<ID> acctIds) {
   Integer count = 0;
   for (Account acct : [select Id, 
                            (select Id, FormulaField__c from Opportunities)
                            from Account where Id IN: acctIds])
     for (Opportunity o : acct.Opportunities)
        if (oppo.FormulaField__c == 'foo') doSomeFooWork();
        else doSomeBarWork();

As a good practitioner of Enterprise Patterns, you convert the code to use a Selector:

public void doSomeWork(set<ID> acctIds) {
   Integer count = 0;
   for (Account acct : AccountsSelector.newInstance()
                            .selectWithOpposById(acctIds))
     for (Opportunity o : acct.Opportunities)
       if (oppo.FormulaField__c == 'foo') doSomeFooWork();
       else doSomeBarWork();

I’m assuming you know how to create selectors and the corresponding entry in Application.cls.

The testmethod using ApexMocks

So, let’s set up a typical ApexMocks testmethod where we mock the AccountsSelector.

@isTest private static void testDoSomeWork() {
  fflib_ApexMocks mocks = new fflib_ApexMocks();

  // Given a mock selector
  AccountsSelector mockAcctsSelector = (AccountsSelector)
      mocks.mock(AccountsSelector.class);

  // Given a mock Selector with stubbed results for FormulaField__c
  mocks.startStubbing();
  mocks.when(mockAcctsSelector.SObjectType)).thenReturn(Account.SObjectType);
  mocks.when(mockAcctsSelector
      .selectWithOpposById((set<ID>)fflib_match.anyObject())
      )
      .thenReturn(mockAcctsWithOppos);
  mocks.stopStubbing();

  // Given injected mocks
  Application.Selector.setMock(mockAcctsSelector);

  // When doSomeWork is invoked
  new MyClass().doSomeWork(new set<ID> {});  // don't care about real AccountIds

  // Then verify (not shown here; 
  // perhaps verify uow.registerNew or uow.registerDirty)

So, the question, is, how do we create mockAcctsWithOppos since we need to have values for Opportunity.FormulaField__c?

There is only one way and that is to create JSON and deserialize into the Account Sobject. I’ve used three ways to do this:

Mocking SObjects with Json – method 1 – hard-coded strings

Account[] mockAcctsWithOppos = 
   (Account[]) Json.deserialize(someJsonString,list<Account>.class);

where someJsonString looks like this (example is a single Account with two Opportunities):

{
  "totalSize" : 2,
  "done" : true,
  "records" : [ {
    "attributes" : {
      "type" : "Account",
      "url" : "/services/data/v41.0/sobjects/Account/0013600001FGf1HAAT"
    },
    "Id" : "0013600001FGf1HAAT",
    "Opportunities" : {
      "totalSize" : 2,
      "done" : true,
      "records" : [ {
        "attributes" : {
          "type" : "Opportunity",
          "url" : "/services/data/v41.0/sobjects/Opportunity/0063600000PPLTPAA5"
        },
        "Id" : "0063600000PPLTPAA5",
        "FormulaField__c" : "foo"
      },
       {
        "attributes" : {
          "type" : "Opportunity",
          "url" : "/services/data/v41.0/sobjects/Opportunity/0063600000PPLTPAA5"
        },
        "Id" : "0063600000PPLTPAA6",
        "FormulaField__c" : "bar"
      }
    ]
    }
  }
]
}

You create this Json by using Workbench to generate a query and paste the results into either an Apex string or stick in a StaticResource.

Mocking SObjects with Json – method 2 – fflib_ApexMocksUtils.makeRelationship

The ApexMocks package includes a utility method that can construct the deserialized Json without you having to create the actual string

// Let's mock two Accounts, one with two Oppos, the other with none
ID[] mockAcctIds = new list<ID>();
ID[] mockOppoIds = new list<ID>();
for (Integer i = 0; i < 2; i++) {
  mockAcctIds.add(fflib_IdGenerator.generate(Account.SObjectType);
  mockOppoIds.add(fflib_IdGenerator.generate(Opportunity.SObjectType);
}

Account[] mockAcctsWithOppos = fflib_ApexMocksUtils.makeRelationship(
   Account.class,
   new list<Account> {
     new Account(Id = mockAcctIds[0], Name = '00Account'),
     new Account(Id = mockAcctIds[1], Name = '01Account')
   },
   Opportunity.Account,  // the relationship field
   new list<list<Opportunity>> {
     new list<Opportunity> { . // Two Oppos for Account[0]
         new Opportunity(Id = mockOppoIds[0], AccountId = mockAcctIds[0], 
                         FormulaField__c = 'foo'), 
         new Opportunity(Id = mockOppoIds[1], AccountId = mockAcctIds[0], 
                         FormulaField__c = 'bar')
     },
     new list<Opportunity>();  // no Oppos for Account[1]
  );

This is nice as it lets you do everything without messy string constants. But the utility is limited to only one child relationship so you can’t use it for mocking Accounts with Cases and Opportunities. I find the list> 4th argument to initially be confusing to construct and get right.

Mocking SObjects with Json – method 3 – sfab_SObjectFabricator

Matt Addy has a nice GitHub package to construct Sobjects that is more descriptive and isn’t limited by the number of children. Here is how to use it:

// Let's mock two Accounts, one with two Oppos, the other with none
ID[] mockAcctIds = new list<ID>();
ID[] mockOppoIds = new list<ID>();
for (Integer i = 0; i < 2; i++) {
  mockAcctIds.add(fflib_IdGenerator.generate(Account.SObjectType);
  mockOppoIds.add(fflib_IdGenerator.generate(Opportunity.SObjectType);
}
Account[] mockAcctsWithOppos = new list<Account> {
  (Account) new sfab_FabricatedSObject(Account.class) [0] has 2 Oppos
      .setField(Account.Id = mockAcctIds[0]).
      .setField(Account.Name = '00Account')
      .setChildren('Opportunities', new List<sfab_FabricatedSObject> {
        new sfab_FabricatedSObject(Opportunity.class)
          .setField(Opportunity.Id, mockOppoIds[0]),
          .setField(Opportunity.AccountId, mockAcctIds[0]),
          .setField(Opportunity.FormulaField__c, 'foo'), 
        new sfab_FabricatedSObject(Opportunity.class)
          .setField(Opportunity.Id, mockOppoIds[1]),
          .setField(Opportunity.AccountId, mockAcctIds[0]),
          .setField(Opportunity.FormulaField__c, 'bar')
    }).toSObject(),
  (Account) new sfab_FabricatedSObject(Account.class) //[1] has no Oppos
      .setField(Account.Id = mockAcctIds[1])
      .setField(Account.Name = '01Account')
      .toSObject()
  };

I like the sfab_SObjectFabricator approach as it is clear where you are defining children (and you can also do parents with setParent()).

Some final remarks

  1. Don’t let the inability to construct SObjects with formula or audit fields get in your way to using ApexMocks to mock either inputs to services or domain layers or mock results from services or domain layers. Choose one of the approaches above or roll your own to exploit Salesforce’s feature of constructing any Sobject’s fields via Json deserialization.
  2. The examples above are probably too verbose for the code-under-test. The Opportunity.AccountId, if never referenced, need not be mocked.
  3. Exploit the Unit of Work layer so you can use ApexMocks to verify that your DML (via registerXXX methods) is done as expected – without having to pay for the cost of real DML.
  4. You will still need what I call ‘end-to-end’ testing that doesn’t use mocks to verify that your selectors work against real data and return all the columns the code expects. You also need to verify that actual DML doesn’t run afoul of Validation Rules that otherwise aren’t executed when you mock the Unit Of Work.
  5. ApexMocks are a great way to explore in detail the unit test use cases by focusing the testing problem on the inputs and outputs of a given class/method.

ApexMocks and Email

Part two of a series. See Part 1 and Part 3

One of the problems in unit testing outbound email is that it is hard to verify that you constructed all of the properties of the outbound email as expected. This is compounded by the fact that sandbox orgs default with email deliverability ‘off’ so any attempt to use Messaging.sendEmail(emails) will throw an exception and your test breaks.

The example’s premise

Suppose we have a simple class method that constructs and sends an email:

public void sendEmail() {
   Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
   mail.setToAddresses(new list<String> {'foo@bar.com'};
   mail.setSubject('Greetings, earthlings!');
   ...
   Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
}

How would you unit test that the outbound email was sent to ‘foo@bar.com’ ? Not so simple. Same for the other properties of the outbound email.

Enter Enterprise Patterns and ApexMocks

Rework the Apex class to use the fflib UnitOfWork:

public void sendEmail() {
   fflib_ISobjectOfWork uow = Application.UnitOfWork.newInstance();
   Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
   mail.setToAddresses(new list<String> {'foo@bar.com'};
   mail.setSubject('Greetings, earthlings!');
   ...
   uow.registerEmail(mail); // let UnitOfWork know mail is part of Txn
   uow.commitWork(); // send the mail
}

The fflib_SobjectUnitOfWorkClass considers outbound emails as part of the transaction, hence the registerEmail(mail) method call.

Now, your testmethod looks like this:

@isTest private static void testSuccessPath() {
  fflib_ApexMocks mocks = new fflib_ApexMocks();
  // Given a mock UoW (injected)
  fflib_SobjectUnitOfWork mockUow = 
     (fflib_SobjectUnitOfWork) mocks.mock(fflib_SObjectUnitOfWork.class);
  Application.UnitOfWork.setMock(mockUow);

  // When the email method is invoked
  new MyClass().sendEmail();

  // Then verify that an email was constructed and sent
  ((fflib_SobjectUnitOfWork) mocks.verify(mockUow,
                                          mocks
                                           .times(1)
                                           .description('email sb constructed')))
    .registerEmail((Messaging.SingleEmailMessage) fflib_Match.anyObject());
    									
    									
  ((fflib_SobjectUnitOfWork) mocks.verify(mockUow,
                                          mocks
                                           .times(1)
                                           .description('email sb sent')))
    .commitWork();

  // Then verify that the email was constructed as expected
  // We use ArgumentCaptors for this. There are four (4) steps:

  fflib_ArgumentCaptor capturedEmailArg	= 
        fflib_ArgumentCaptor.forClass(Messaging.SingleEmailMessage.class);
  ((fflib_SobjectUnitOfWork) mocks.verify(mockUow,1))
       .registerEmail((Messaging.SingleEmailMessage)capturedEmailArg.capture());

  Object actualEmailAsObject = capturedEmailArg.getValue();
  Messaging.SingleEmailMessage actualEmail = 
        (Messaging.SingleEmailMessage) actualEmailAsObject;

  System.assertEquals('Greetings, earthlings!', 
                       actualEmail.getSubject(),
                       'subject is from friendly aliens');
  System.assertEquals(new list<String> {'foo@bar.com'},
                       actualEmail.getToAddresses()
                       'only @bar.com domains expected');
  ... other properties.
}

Let’s look at the argumentCaptor, one line at a time.

fflib_ArgumentCaptor capturedEmailArg	= 
        fflib_ArgumentCaptor.forClass(Messaging.SingleEmailMessage.class);

We declare a variable of type fflib_ArgumentCaptor and set it to be of the type we want to inspect.

((fflib_SobjectUnitOfWork) mocks.verify(mockUow,1))
       .registerEmail((Messaging.SingleEmailMessage)capturedEmailArg.capture());

We ask the mocking framework that when the UnitOfWork object is called with method registerEmail with single argument of type Messaging.SingleEmailMessage that we want to capture the value of that argument when the mock UoW is called. The capture() method of ApexMocks library does this. Note we use the mocks.verify(..) method to do this. That is, instead of verifying the value passed to registerEmail we are capturing that value for later inspection.

Object actualEmailAsObject = capturedEmailArg.getValue();
  Messaging.SingleEmailMessage actualEmail = 
        (Messaging.SingleEmailMessage) actualEmailAsObject;

Our declared variable capturedEmailArg has a method getValue() provided by the fflib_ArgumentCaptor class. It returns an Object. There is also a getValues() method for collections. We cast this to the type we care about – Messaging.SingleEmailMessage.

Now, we can assert against the actual email that the class-under-test constructed and verify each property.

System.assertEquals('Greetings, earthlings!', 
                       actualEmail.getSubject(),
                       'subject is from friendly aliens');

So, why is this cool?

  1. We are immune from the sandbox having to be configured to send emails. Because fflib is already unit tested, calls to registerEmail(someEmail) followed by commitWork() will send emails in an org configured to send emails. We merely need to verify that registerWork and commitWork got called. Since the UnitOfWork layer is mocked, we can use ApexMocks to verify that calls to a mockUow are as expected.
  2. The fflib_ArgumentCaptor feature of ApexMocks allows detailed inspection of arguments passed to any mockable class/method. In our example, it is a single argument of type Messaging.SingleEmailMessage, but it could be any arbitrary Apex type. Thus, your unit tests can be quite exhaustive about verifying that the contract between two objects is fulfilled without having to construct any real Sobjects, do any real DML, or query for the results.

Apex Mocks and Enterprise Patterns (First in a Series)

It took me a bit to get here but I can unequivocally state that Apex Mocks is well worth learning to improve your unit testing.

This blog post aims at the Apex developer who doesn’t have Java Mockito experience (which was me). Since most of the code at our org relies on the Apex Enterprise Patterns, the examples herein will exploit that. The most useful reference to me was chapter 11 – Unit Testing of Force.com Enterprise Architecture although there were some typos in the code examples in my printed copy.

See also Part 2 (Unit Testing email), and Part 3 (Selector mocking with formula fields)

The scenario
You have a CasesService, method reopen(set csIds)

Here’s the code: Note use of the Unit of Work Pattern

public virtual class CasesServiceImpl implements ICasesService{

    /**
    *	reopen	- reopen a set of Cases
    **/
    public virtual void reopen(set<ID> csIds) {
        try {
            fflib_ISobjectUnitOfWork uow = Application.UnitOfWork.newInstance();
        	reopen(uow,csIds);
        	uow.commitWork();
        }
        catch (Exception e) {
            throw new CasesService.CaseReopenException(e.getTypeName() + ' ' + e.getMessage() + ' ' + e.getStackTraceString());
        }
    }
    

    public virtual void reopen(fflib_ISobjectUnitOfWork uow, set<ID> csIds) {
        for (ID csId : csIds) {
            uow.registerDirty(new Case(Id = csId, Status = Cases.STATUS_NEW));
        }    
    }
    
}

I’m presuming if you are reading this, that you already know the Apex Enterprise Pattern and have created the ICasesService.cls, CasesService.cls, and updated the Application.cls.

Unit testing the service
In “classic” Apex development, you would test the CasesServiceImpl.reopen(set csIds) method by creating via DML a Case record (this might also require creating an Account and Contact record). Sort of like this:

@isTest private static void testCaseReopen() {
   Account[] mockAccts = new list<Account> {
     new Account(...),
     new Account(...)
     ...
   };
   insert mockAccts;
   // and so on for the Contacts (mockContacts) and Cases (mockCases)

   Test.startTest(); 
   CasesService.reopen(new set<ID> (new map<ID,Case>(mockCases).keySet());
   Test.stopTest();
   Case[] resultCases [select Id, Status from Case];
   for (Integer i = 0; i < resultCases.size(); i++)
      System.assertEquals('New',resultCases[i].Status,
                          '['+i+'] Status should be New');
}

So boring. And so much DML that makes your tests run longer – especially if you have hundreds or thousands of tests. You have to query the database to test your asserts. Think about testing Opportunities – Accounts, Contacts, Opportunities, Pricebooks, Product2s, PricebookEntries, and OpportunityLineItems may all have to be inserted into the database.

And here’s the beauty
Because you are using Apex Enterprise Patterns, you recognize that the reopen method only needs to be passed in Case Ids and then verified that the Cases were registered as dirty and that commitWork was called.

  • You don’t need real Cases to generate valid Case Ids
  • You don’t need to query the updated records to see if the Status was changed. Instead, you just need to know that registerDirty() was called with the expected status of ‘New’. As long as commitWork() was called, you can rely on the updates being done (written to the database) because commitWork() is already unit tested by the fflib library.


So, what does the unit test look like?

I’ll start off by saying that the syntax takes a bit of time getting used to. I’ll try to comment each step

@isTest private static void testReopen() {
  /** variable mocks represents the mocking framework object. 
     You can call it anything **/
  
  fflib_ApexMocks mocks = new fflib_ApexMocks();  // required and first
 
  // Given Case Ids to reopen 
  /** We use fflib to generate valid-for-the-sobjectType IDs **/
  
  ID[] mockCaseIds = new list<ID>();
  for (Integer i = 0; i < 2; i++) // 2 is arbitrary but goal is bulk testing 	
    mockCaseIds.add(fflib_IdGenerator.generate(Case.SobjectType));

  // Given mock UnitOfWork
  fflib_SobjectUnitOfWork mockUow = (fflib_SobjectUnitOfWork) 
                                       mocks.mock(fflib_SObjectUnitOfWork.class);
  Application.UnitOfWork.setMock(mockUow); // inject the mock for fflib factories

  /** Wrap your service call in try catch so you can easily debug any errors **/
  // When service invoked
  try {
   CasesService.reopen(new set<ID>(mockCaseIds)); 
  }
  catch(Exception e) {
   System.assert(false,'snb, service method sb success; ' + showException(e));
  }

  // Then verify Case status is New and objects committed 
  /** mocks.verify takes two arguments:
       1 - the object being mocked - in this case, the UnitOfWork
       2 - an object of type fflib_VerificationMode. 
           This object supports a fluent pattern with methods:
            times(n) - how many times the mock object's method M is called
            atLeast(n) - method called at least n times
            atMost(n) - method called at most n times
            atLeastOnce() - method called at least one time
            between(m,n) - method called between m and n times
            never() - method never called
            calls(n) - method called n times w/ InOrder verifier (see doc)
            description(text) - equivalent to the third argument for System.assertEquals()
  
       Once cast to the type of the mock object, then verification is that the 
       registerDirty method was called (twice) with an Sobject of type Case
  **/         
  ((fflib_SobjectUnitOfWork) 
    mocks.verify(mockUow,mocks
                  .times(2)
                  .description('both Cases should be marked as Closed'))
  )
   .registerDirty(fflib_Match.sObjectOfType(Case.SObjectType));


  /** In this verify, assert registerDirty was called with an SObject matching 
      1 - Case.Id = the first mocked CaseId
      2 - Case.Status is 'New'

     This is done with a matcher (type = fflib_Match) argument. 
     The framework looks to see if the method (registerDirty) 
     was called with an argument that "matches" the matcher.

     There are a large number of matchers, see class
     fflib_Match (most of the Mockito matchers are mirrored). 
     One of the Apex-specific ones is sObjectWith that takes a map of
     SObjectField => Object
  **/

  ((fflib_SobjectUnitOfWork) 
    mocks.verify(mockUow,mocks
                  .times(1)
                  .description('Case[0] sb reopened'))
  )
   .registerDirty(fflib_Match.sObjectWith(new map<SObjectField,Object> {
        Case.ID => mockCaseIds[0],    																			
        Case.Status => Cases.STATUS_NEW}));
		
  /** In this verify, assert the second Case ID also became status New **/
  ((fflib_SobjectUnitOfWork) 
    mocks.verify(mockUow,mocks
                  .times(1)
                  .description('Case[1] sb reopened'))
  )
   .registerDirty(fflib_Match.sObjectWith(new map<SObjectField,Object> {
        Case.ID => mockCaseIds[1],    																			
        Case.Status => Cases.STATUS_NEW}));

  /** Finally, assert records were committed to Database. 
      As commitWork has no args there is no Matcher **/

  ((fflib_SobjectUnitOfWork) 
    mocks.verify(mockUow,mocks
                   .times(1)
                   .description('both Cases should be committed'))
  )
   .commitWork();

}

Some meta remarks

  1. Using ApexMocks requires some wordy syntax that is not immediately apparent when you first see it
  2. It is especially useful for unit testing smallish methods that have few dependencies (which is how they should be written in the first place). Doing unit testing improves your confidence that methods will do what they are supposed to do when orchestrated into larger transactions.
  3. You can mock only non-static methods of objects.
  4. You need to invest time in learning how Matchers work. The class fflib_Match and fflib_ApexMocksTest are helpful. So are Mockito books and the Mockito web site
  5. As we’ll see in subsequent posts, you can mock selectors including formula fields and system audit fields without having to do any DML or SOQL. You can also mock the domain layer and service layer, and for that matter any non-static object method (except async)

The goal of this post was to explain the syntax. Try it out on a small class and you’ll feel you are up’ing your Unit test game, hence leaving a stronger legacy of test code to yourself, your team members, and your successors.