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Pranav ChitransPranav Chitrans 

How to write test class for trigger

Hello everyone, plz tell me how to write the test class for this trigger listed below..
trigger ConTest on Account(after insert,after Update)
 if(trigger.isInsert && trigger.isAfter)
  List<Contact> lstCon = new List<Contact>();
  for(Account acc :
   Contact con = new Contact();
   con.AccountId = acc.Id;
 if(trigger.isUpdate && trigger.isAfter)
  Map<Id,Account> mapACC = new Map<Id,Account>([select (select id,name from contacts) from account where id IN:]);
  List<Contact> newCon = new List<Contact>();
  for(Account updatedAcc : trigger.New)
   Account oldAcc = trigger.oldMap.get(updatedAcc.Id);
   if(mapACC.ContainsKEY(updatedAcc.Id) && oldAcc.Name != updatedAcc.Name)
 for(Contact con : mapACC.get(updatedAcc.Id).contacts)
     con.lastname = updatedAcc.Name;
  update newCon;

Thanks in advance :)
karunakarreddy bade 8karunakarreddy bade 8
Hi pranav

I think this documentation is worth reading through for a better understanding of test class for triggers.


since triggers fire on dml just need to do the relevant dml operations .Try below code
private class ApexTest_AccountTrigger
    static testMethod void TestAccount()
       Account a = new Account();
	   a.Name ='Test Account';
	   insert a;
	   a.Name = 'Test Account 2';
	   update a;

Pranav ChitransPranav Chitrans
Hi Sura,
Actually i cannot clear one of my doubt... how this apex test class come to know whch trigger we are testing.... there is no such link with this test class to my trigger.. plz tell me
Hi Pranav,

You have written a trigger on Accout Object. Now you need to cover the code of that trigger. And we know that trigger code is always fire on event of that object reocrd for which it was written and for which event.

Now according to your trigger code it will fire when a record is updated or created (After for both). Now you need to write a test class in which you just need to insert a account record and than need to update that account with the same condition which you have cover in the Trigger code so it will cover all the cases.

Sura has provide the code in which code is inserted the account and then updating the record so tirgger will fire on both cases.

-Hope it will help you to understand.

Ashlekh Gera 
Pranav ChitransPranav Chitrans
hey AKG,
plz do me a favour.. write down the full test class for my trigger.. i am getting cnfused where to write write dml events in test class under the static method or outside of it... can u wrtie the code.
thnx in advance
Amit Chaudhary 8Amit Chaudhary 8
Please try below code. I hope that will help you.

NOTE:- for Trigger test class you just need to perform the DML inside your testMethod.
private class ConTest_Test
    static testMethod void TestAccount()
       Account acc = new Account();
	   acc.Name ='Test';
	   insert acc;
	   acc.Name = 'Test Acc';
	   update acc;
Please check below post for test classes. I hope that will help u

Please follow below salesforce Best Practice for Test Classes :-

1. Test class must start with @isTest annotation if class class version is more than 25
2. Test environment support @testVisible , @testSetUp as well
3. Unit test is to test particular piece of code working properly or not .
4. Unit test method takes no argument ,commit no data to database ,send no email ,flagged with testMethod keyword .
5. To deploy to production at-least 75% code coverage is required
6. System.debug statement are not counted as a part of apex code limit.
7. Test method and test classes are not counted as a part of code limit
9. We should not focus on the  percentage of code coverage ,we should make sure that every use case should covered including positive, negative,bulk and single record .
Single Action -To verify that the the single record produces the correct an expected result .
Bulk action -Any apex record trigger ,class or extension must be invoked for 1-200 records .
Positive behavior : Test every expected behavior occurs through every expected permutation , i,e user filled out every correctly data and not go past the limit .
Negative Testcase :-Not to add future date , Not to specify negative amount.
Restricted User :-Test whether a user with restricted access used in your code .10. Test class should be annotated with @isTest .
11 . @isTest annotation with test method  is equivalent to testMethod keyword .
12. Test method should static and no void return type .
13. Test class and method default access is private ,no matter to add access specifier .
14. classes with @isTest annotation can't be a interface or enum .
15. Test method code can't be invoked by non test request .
16. Stating with salesforce API 28.0 test method can not reside inside non test classes .
17. @Testvisible annotation to make visible private methods inside test classes.
18. Test method can not be used to test web-service call out . Please use call out mock .
19. You can't  send email from test method.
20.User, profile, organization, AsyncApexjob, Corntrigger, RecordType, ApexClass, ApexComponent ,ApexPage we can access without (seeAllData=true) .
21. SeeAllData=true will not work for API 23 version eailer .
22. Accessing static resource test records in test class e,g List<Account> accList=Test.loadData(Account,SobjectType,'ResourceName').
23. Create TestFactory class with @isTest annotation to exclude from organization code size limit .
24. @testSetup to create test records once in a method  and use in every test method in the test class .
25. We can run unit test by using Salesforce Standard UI, IDE ,Console ,API.
26. Maximum number of test classes run per 24 hour of period is  not grater of 500 or 10 multiplication of test classes of your organization.
27. As apex runs in system mode so the permission and record sharing are not taken into account . So we need to use system.runAs to enforce record sharing .
28. System.runAs will not enforce user permission or field level permission .
29. Every test to runAs count against the total number of DML issued in the process .

Please let us know if this post will help you

Amit Chaudhary