An extended look: How to write a test class

Preface: this post is part of the Write Your First Trigger From Start to Finish series.

Want to get a deeper understanding of our test class? Let’s do this!

Here’s the code we wrote in our previous post to test our simple trigger:

@isTest 
public class TestForceForecasting {
    static testMethod void insertNewUser() {
       
       User userToCreate = new User();
       
       // Do you recognize these fields?
       userToCreate.FirstName = 'David';
       userToCreate.LastName  = 'Liu';
       userToCreate.Email     = 'dvdkliu@gmail.com';
       userToCreate.Username  = 'sfdc-dreamer@gmail.com';
       userToCreate.Alias     = 'fatty';
       userToCreate.ProfileId = '00ei0000000rTfp';
       // Don't worry about these
       userToCreate.TimeZoneSidKey    = 'America/Denver';
       userToCreate.LocaleSidKey      = 'en_US';
       userToCreate.EmailEncodingKey  = 'UTF-8';
       userToCreate.LanguageLocaleKey = 'en_US';
       
       insert userToCreate;
    }
}

All the test code does is create a new user using Apex, thereby triggering the execution of our simple trigger.

Let’s start with the outer layers. All this code does is tell Salesforce we are writing test code. These lines aren’t that important because they’ll be virtually the same no matter what you’re testing.

@isTest 
public class TestForceForecasting {
    static testMethod void insertNewUser() {
        . . . 
   }
}

This next line is important! This is how we create new records using Apex. You can replace the blue text with any sObject and it’ll still work.

       User userToCreate = new User();

This is how we write “comments” in Apex! Salesforce skips any line of code beginning with //

       // Do you recognize these fields?

This kind of code below should look familiar to you. All we’re doing is setting fields on our new user. The last line is highlighted because it’s populating a lookup field using a ProfileId – just like you would if you were doing this via Data Loader. Note that all these fields are required fields when creating a user.

       userToCreate.FirstName = 'David';
       userToCreate.LastName  = 'Liu';
       userToCreate.Email     = 'dvdkliu@gmail.com';
       userToCreate.Username  = 'sfdc-dreamer@gmail.com';
       userToCreate.Alias     = 'fatty';
       userToCreate.ProfileId = '00ei0000000rTfp';

These are more required fields that probably look unfamiliar to you. Don’t worry about these – I promise you’ll rarely need to think about this stuff!

       // Don't worry about these
       userToCreate.TimeZoneSidKey    = 'America/Denver';
       userToCreate.LocaleSidKey      = 'en_US';
       userToCreate.EmailEncodingKey  = 'UTF-8';
       userToCreate.LanguageLocaleKey = 'en_US';

Final line – this one is key! Until we explicitly insert our user into our Salesforce database using this DML code, it only exists in the matrix! ooo..

       insert userToCreate;

Glossary of variables used:

@isTest – this tells Salesforce we’re writing test code

TestForceForecasting – this is the name we gave to our test class. Imagine a class to be like a folder – it helps us organize our code.

testMethod – this tells Salesforce once again that we’re doing a test. Pretty redundant huh?

insertNewUser – the name we gave our test method. If a class is like a folder, a method is like a document inside our folder that has instructions for tasks. A class can have many methods.

User – the API name of any Salesforce sObject, in this case, the standard User object.

userToCreate – the variable we named to store our user record.

’00ei0000000rTfp’ – this is the ID of the profile we’ll give to our user. Note that your org will have different IDs. 15-digit record IDs can be found in the URL of any record. Like text, IDs need to be wrapped in single quotes.

insert – the DML statement to “create” a record in an org. The record only exists in our code until we save it using DML.

Want to see this and all other code samples on this site in an actual Salesforce org? Log in to sfdc99!

Next post: How to deploy code from Sandbox to Production