fflib-apex-mocks

Use when() to define canned responses for method calls on a mock object. To prevent side effects or unexpected behavior during the setup phase, you must wrap your stubbing logic between startStubbing() and stopStubbing().

fflib_ApexMocks mocks = new fflib_ApexMocks();
fflib_MyList.IList mockList = (fflib_MyList.IList)mocks.mock(fflib_MyList.class);

mocks.startStubbing();
mocks.when(mockList.get(0)).thenReturn('bob');
mocks.when(mockList.get(1)).thenReturn('fred');
mocks.stopStubbing();

Use the verify() method to ensure that specific methods on a mock object were called with the expected arguments and frequency. If the invocation does not match the expectation, an exception is thrown containing details about the expected vs. actual counts and arguments.

You can also use fflib_ApexMocks.NEVER to verify that a method was specifically NOT called.

// Given
fflib_ApexMocks mocks = new fflib_ApexMocks();
fflib_MyList.IList mockList = (fflib_MyList.IList)mocks.mock(fflib_MyList.class);

// When
mockList.add('bob');

// Then
((fflib_MyList.IList) mocks.verify(mockList)).add('bob');
((fflib_MyList.IList) mocks.verify(mockList, fflib_ApexMocks.NEVER)).clear();

Since formula fields and other read-only fields cannot be set directly on SObjects, use fflib_ApexMocksUtils.setReadOnlyFields to inject values into them for testing purposes. This method returns a new instance of the SObject with the specified fields populated.

Account acc = new Account();
Integer mockFormulaResult = 10;
acc = (Account)fflib_ApexMocksUtils.setReadOnlyFields(
		acc,
		Account.class,
		new Map<SObjectField, Object> {Account.Your_Formula_Field__c => mockFormulaResult}
);
System.assertEquals(mockFormulaResult, acc.Your_Formula_Field__c);

ApexMocks leverages the Salesforce Stub API to dynamically generate mock implementations of classes or interfaces at runtime. Use the mock() method on an instance of fflib_ApexMocks to create these objects.

fflib_ApexMocks mocks = new fflib_ApexMocks();
fflib_MyList mockList = (fflib_MyList)mocks.mock(fflib_MyList.class);