Unit Testing In Apex: Strategies For Success

by Bisera Runcheva

Testing has become essential for the development process in today’s rapidly evolving software development landscape. Testing ensures software systems' reliability, functionality, and security, safeguarding against costly errors and enhancing user experience.

In this blog, I will delve into the world of Apex unit testing, focusing on sharing invaluable tips and best practices, empowering developers to elevate their Salesforce development game.

What is Apex Unit Testing?

Unit testing is checking small pieces of code to ensure that the tested section behaves as intended. An Apex unit test consists of an Apex Class, which is annotated with @isTest and can contain multiple test methods to verify whether a particular piece of code is working properly. Different test methods are created to test different functionalities. These methods have the following characteristics:

Best Practices In Apex Unit Testing

A well-written Apex unit test is crucial for maintaining the integrity and effectiveness of your code validation process. Following these guidelines improves the quality and reliability of the software and makes the development process smoother. Here are some key approaches:

1. Keep an eye on code coverage

To deploy a new functionality to production, at least 75% code coverage is required, but in real-life scenarios, it is advised to focus on 90%+. Furthermore, it is crucial that every use case, such as positive and negative scenarios, is covered.

2. Isolate Test Data

Avoid creating test data in test methods, especially if it’s data that is common for multiple test methods. Using a @testSetup method helps because it creates data once and is available for any test method in the test class. Another approach would be to use a TestDataFactory utility class containing reusable code for test data creation.

3. Don’t forget about governor limits

Remembering Salesforce Governor Limits is crucial, as they play a significant role in the platform’s functionality. We can keep an eye on our governor limits using methods of Limits Class and the Test.startTest() and Test.stopTest() methods. We can use the Limits Class to get information about specific resources. Each method of the Limits Class has two versions: the first version returns the amount of the resource used, whereas the second version returns the total amount of the available resource. On the other hand, we can use Test.startTest() and Test.stopTest() to avoid hitting governor limits in our test. Test.startTest() gives us a new set of governor limits, meaning after calling this function, we can call the desired code we want to test and see its behavior. The old governor limits will be applied when the code reaches Test.stopTest().

4. Use Assert class

Utilize methods of the Assert class to check if certain conditions are true or false. This class allows you to check whether the code functions as it should.

5. Use the Test.setFixedSearchResults() method

If your code is executing a SOSL query, this method comes to the rescue. With the Test.setFixedSearchResults() method, you can set the results that will be returned from all SOSL queries in the code being tested. This gives you full control of the retrieved data and allows you to test different scenarios.

6. Avoid SeeAllData=true

By annotating your class with @isTest(SeeAllData=true), you allow test methods to access existing data. There are better practices than this. The more advised approach is to have SeeAllData=false and rely on your created test data.

7. Use @testVisible annotation

If you need to test a private class or method, use this annotation to make the class or method visible to test classes and methods.

8. Test Exception Scenarios

Your test classes should cover scenarios where an exception occurs. A good test class can handle errors smoothly.

9. Use the runAs() method

Using this method helps you ensure how the functionality executes when different user contexts are used.sal with different permissions use it.

Embracing Unit Testing pays off handsomely

Mastering Apex unit testing and adhering to best practices are critical to building dependable Salesforce applications. These practices ensure smoother development, reduced bugs, and enhanced end-user satisfaction. If you start embracing them, your development journey will become smoother, and your coding skills will sharpen.