how to write a test class for trigger that calls future method?

Question

trigger CaseTri on Case (after insert) {
    if(Trigger.isAfter){
        if(Trigger.isUpdate){
             if(classA.Method1){    
                webServices.notify(Trigger.New[0].Id);
                ClassA.Method1 = true;                
             }
        }
        if(Trigger.isAfter){
            if(Trigger.isInsert){
                if(ClassA.method1) {  
                    webservice.CcNotification(Trigger.New[0].Id);
                    ClassA.method1 = true;
                }
            }
        }

webservice.CcNotification(Trigger.New[0].Id);->line which calls future method

My testclass:

@isTest(SeeAllData=true)
public class CaseTri{
public static testMethod void testnotif(){
Case c = new Case();
insert c;
Test.startTest();
Test.setMock(WebServiceMock.class, new WebServiceMockImplnotif());


  Test.stopTest();
}
}

Answer 1

When performing tests, you only have one bite at the apple when it comes to executing Async methods.

Since you have two different conditions in your trigger it is wise to write two separate test methods so that you can properly assert the results. It gets complex if you do both the insert and update before the stop test. Maybe not in this case but in larger implementations so I am going to show you the multi method way

Note I do not know what the ClassA.method1 criteria is so ensure the records meet the criteria.

Important Point: Any future methods hit before the test.startTest will not be executed when the execution hits test.stoptest

Update Your Trigger: trigger CaseTri on Case (after insert, after update)

Test Class Framework

@isTest
public class CaseTri{

    public static testMethod void insertTest(){
        Case c = new Case();

        Test.startTest();
        Test.setMock(WebServiceMock.class, new WebServiceMockImplnotif());
        //You need to do the Insert inside of the Test.start and test.stoptest or the future method will never be executed
        insert c;

        Test.stopTest();

        //Query for your records
        .....
        //Assert for proper results

    }

    public static testMethod void insertTest(){
        Case c = new Case();
        //Do this here so the future method for the insert does NOT get queued up after the stop test
        insert c;
        Test.startTest();
        Test.setMock(WebServiceMock.class, new WebServiceMockImplnotif());
        //You need to do the update inside of the Test.start and test.stoptest or the future method will never be executed
        update c;

        Test.stopTest();

        //Query for your records
        .....
        //Assert for proper results

    }


}

Answer 2

Include a Test.stopTest() in your test method; that will ensure that the async call (the future) has completed so you can assert the expected outcome.