function readOnly(count){ }
Starting November 20, the site will be set to read-only. On December 4, 2023,
forum discussions will move to the Trailblazer Community.
+ Start a Discussion
Sangeetha TSangeetha T 

Test class for apex trigger for code coverage while production migration from sandbox

Need test class for the following trigger with atleast 75 code coverage 

The below trigger  : Opportunity has a field where the associated  contact name should be populated (after lead conversion to acc,contact,opp)
trigger ContactNameUpdate on Lead (after update) 
  for(Lead l : 
   if(l.IsConverted && l.ConvertedOpportunityId != null) 
    Opportunity opp = [SELECT Id,Contact__c FROM Opportunity WHERE Id =: l.ConvertedOpportunityId];
    If(opp.Contact__c == null)
     opp.Contact__c = l.ConvertedContactId;
     update opp;
Please give me the test class to cover 75 of code coverage to migration.......Very Critical
Please give me the test class to cover 75 of code coverage to migration.......Very Critical
praveen sonepraveen sone
private class ContactNameupdateTest{
    static testmethod void positivetest(){
        Lead l = new Lead(); // Insert all mandatory fields
        l.isconverted = true;
        l.convertedopportunityId = opp.Id;
        Insert l;
        Opportunity opp = new opportunity(); // Insert all mandatory fields
        Insert opp;
        List<opportunity> newopp = [select Id, contact__c from opportunity where Id = l.convertedopportunityId];
        System.assertEquals(l.convertedcontactId, newopp[0].contact__c);

This should cover your positive scenario. please try saving it in your org and execute.
@Sangeetha T:
  1. When you convert a Lead, the default platform functionality creates a Contact from the Lead and then associates that Contact as a "Contact Role" on the new Opportunity and marks it as "Primary".
    • I am wondering why you need to write code to also place the Contact in a custom Lookup field on the Opportunity. What is the requirement to do this?
  2. The code you have for your "ContactNameUpdate trigger" is not "bulkified" and you will blow an Apex Limit on any bulk updates/inserts on Lead records.
    • You are doing one SOQL query and one DML event per each record versus first identifying the records you need to process, placing them into a list/map and then passing to an Apex class for bulk processing
      • Best practice is not to include business logic at the trigger level and place it in a class to promote reusability
    • You can learn about best practices here:
I am pointing this out to you as I want to help you avoid common issues.  :-)
Amit Chaudhary 8Amit Chaudhary 8
Please check below post for test classes i hope that will help you
Please try below test class. I hope that will help you
private class ContactNameupdateTest
    static testmethod void positivetest()
		Lead testLead = new Lead();
		testLead.FirstName = 'Test First';
		testLead.LastName = 'Test Last';
		testLead.Company = 'Test Co';
		// Add all required field here
		insert testLead;
			Database.LeadConvert lc = new database.LeadConvert();

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

Sangeetha TSangeetha T
Hi ppl thanks for your instant reponse ...but both didnt work