When testing can I not use existing Data?

Question

I am currently programming a trigger on Opportunities.

I created a test class for this and in my Sandbox I created an account, contact and opportunity. When I try to reference them

Opportunity Opp = [SELECT id from Opportunity where name = 'Test1']; 

and then start my

Test.startTest();
        Opp.StageName = 'PO in (100%)'; 
        update Opp; 
       Test.stopTest();

It just errors and shows that Opp returns 0 rows. However when I paste my first bit of code in 'Execute Anonymous' it returns a row and the correct info.

Does this mean I have to create an account, contact, quote and all necessary fields in my test class?

Answer 1

Do not use existing data. It is a terrible practice for it and there is almost never a need to do it. Using existing data will cause serious issues whenever you create a new sandbox or attempt to move any code to a different organization.

It is considered a very bad practice. There is a reason Salesforce removed the ability to access data from the system by default in version 24. Problems like - UNABLE_TO_LOCK_ROW error while running all apex test classes - pop up when running asynchronous tests. Avoid those problems now and write the tests with the best practice right out the gate.

Here is some good documentation on writing unit tests.

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EDIT: A common practice my coworkers and I have used is creating a TestUtils class and using that class to create the data model. That would allow you to do something like:

@isTest
public class TestUtils{
    public static Account getAccount(){
        Account acc = new Account(Name = 'Account');
        insert acc;
        return acc;
    }
}

then from your test method:

@isTest
public class TestClass{
    static testMethod void myTest() {
        Account acc = TestUtils.getAccount();
    }
}

This will generate an account, insert it into the DB, and then return it to be used in the test. This can then be reused around the system.

Answer 2

Adding to Rao and user31's responses. . . by design, test classes do not have access to your org's data unless you explicitly set SeeAllData=true. There are multiple problems with relying upon pre-existing data:

1. You have no way of guaranteeing the data you expect will exist
2. You have no way of guaranteeing the data you retrieve will accurately run through your tests

By setting up your own test data you:

1. You remove problems with locks
2. Know exactly what is present with regards to good and bad data
3. Can help improve your testing by having proper edge cases tested
4. Remove dependencies outside of your control

Answer 3

If you are absolutely sure there will be sample data in the org (eg this runs in a Trial), you can use the @isTest(SeeAllData=true) annotation... but you probably shouldn't!

Answer 4

The highest recommendation and best practice is to create data on the flow and not to use Existing data

Disadvantages of using Seealldata: I have seen lock errors due to test class trying to access the data during deployments/ user trying to modify a record( Which was assumed to be a test data in the test class)

Always stick on to create that update, but scenarios like Profile, Recordtypes are some cases where you can query and not have to create the record.

Update for using recordtype in test class : Check out the code below without using a actual query you can pull the recordtype info

check this blog : http://salesforceapexcodecorner.blogspot.com/2012/03/record-type-for-crating-test-class-data.html

public class seealldatatest{
list<account> acc{get;set;}
public seealldatatest(){
acc = [select id,recordtype.name from account limit 10];
}
public void testingdata(){
    for(account a: acc){
        if(a.recordtype.name == 'Japan'){
        // do something
        }
    }
}
@Istest
public static void testmeth1(){
Schema.DescribeSObjectResult cfrSchema = Schema.SObjectType.Account; 
Map<String,Schema.RecordTypeInfo> AccountRecordTypeInfo = cfrSchema.getRecordTypeInfosByName();  
Account Acc = new Account(Name='test',recordtypeid=AccountRecordTypeInfo .get('Japan').getRecordTypeId());
insert Acc;
seealldatatest s_test = new seealldatatest();
s_test.testingdata();
}
}