Achieve 100% Test Coverage in Your Apex Code: A Guide

Learn how to write an effective test class for your Apex code that ensures `100% test coverage` and improves the reliability of your Salesforce applications.
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This video is based on the question https://stackoverflow.com/q/62418894/ asked by the user 'Carolyn Cordeiro' ( https://stackoverflow.com/u/12934138/ ) and on the answer https://stackoverflow.com/a/62427155/ provided by the user 'Priyanshu' ( https://stackoverflow.com/u/6554615/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Achieve 100% Test Coverage in Your Apex Code: A Guide

Creating test classes in Salesforce is essential for ensuring that your Apex code runs as intended and handles various scenarios. In this post, we’ll walk through how to improve your test coverage from 66% to a perfect 100% for a given Apex class, specifically focusing on the PickListHandler class. We’ll discuss the common pitfalls and provide clear steps to write an effective test class.

Understanding the Problem

The PickListHandler class is designed to fetch data from the Case_Type_Data__c object. However, if the required test data isn't set up correctly, the logic inside the class won’t execute. As a result, your test class might only achieve 66% coverage, largely because the code within the for loop isn't being called at all.

The core question is: How can we write a test class that provides the necessary data and leads to 100% test coverage?

Solution Overview

To achieve 100% test coverage, we need to:

Create Test Data: Populate the relevant object (Case_Type_Data__c) with test records.

Modify the Test Class: Ensure the test class calls the method we want to test effectively.

Let’s break these steps down further.

Step 1: Create Test Data

Before you can test the getLevel1 method, you need records in Case_Type_Data__c. This is critical because the method relies on data being present in order to execute the logic within the for loop.

Example of how to create such data in your test class:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Modify the Test Class

Above, we not only created the records needed for the Case_Type_Data__c but also modified the assertion statements to ensure our test checks whether the function behaved as expected:

We used System.assertEquals to compare the expected size of the list returned to the actual size. This helps verify that our method is functioning correctly.

Conclusion

By creating the appropriate test data and structuring your test method to engage the logic within the original class, you ensure 100% code coverage. This not only helps in passing your test but also solidifies the understanding that your method can handle expected inputs effectively.

Ensuring complete test coverage is crucial in maintaining robust Salesforce applications. Remember that writing effective test classes is just as important as writing clean code. With the above steps, you're well on your way to mastering this skill!