Unit testing is an essential part of Apex development in Salesforce, ensuring that your code is robust, scalable, and reliable. As a Salesforce developer, you should be familiar with the best practices for writing effective test classes. Here are essential Tips that will help you enhance your Apex Unit Testing skills and make the most of Salesforce’s testing framework. Let start our 12 Apex Unit Test Tips Every Salesforce Developer Should Know.
1. Understand the Code Storage Limits
Salesforce allows up to 6 MB of Apex code storage in each org. However, Test classes annotated with @isTest do not count toward this limit. This means you can write comprehensive Test classes without worrying about exceeding your storage capacity. Use this to your advantage by creating as many Test classes as necessary to thoroughly test your code.
2. No Separate Database for Testing
While Salesforce automatically rolls back data changes made during test execution, it still uses the same database as your production environment. This can lead to issues, especially with objects that have unique field constraints. For example, attempting to insert duplicate records in a test could result in errors. Always design your tests with data isolation in mind to prevent conflicts and maintain clean test environments.
3. Test Methods Don’t Send Emails
Worried about accidentally sending emails to users while running Tests? Don’t be! Salesforce Test methods do not trigger real emails. This is a valuable feature for testing email alerts, and triggers without the risk of spamming users or admins.
4. Handle External Callouts with Mock Callouts
Apex Test methods cannot make real callouts to external services. Instead, use mock callouts to simulate API responses and test your callout logic. Implement the HttpCalloutMock interface to create mock responses, ensuring your tests are not dependent on external systems or network conditions.
5. Manage SOSL Searches Effectively
By default, any SOSL (Salesforce Object Search Language) search in a Test method will return empty results. To ensure predictable outcomes, use Test.setFixedSearchResults to specify the records that your SOSL queries should return. This allows you to control the Test data and avoid unexpected results.
6. Use Test.startTest and Test.stopTest
Salesforce provides the Test.startTest and Test.stopTest methods to create a fresh set of governor limits within the test context. Wrapping your test code with these methods helps simulate real-world conditions and ensures that your code behaves correctly under standard governor limits, especially when performing bulk operations or callouts.
7. Achieve High Code Coverage, but Focus on Quality
Salesforce requires a minimum of 75% code coverage for deployment, but don’t just aim for the minimum! Focus on writing meaningful Tests that validate both positive and negative scenarios, covering all branches of your logic. Quality is more important than quantity when it comes to Testing; ensure your tests thoroughly check the functionality, edge cases, and error handling.
8. Test for Bulk Operations
Salesforce processes data in bulk, so your Apex code should be designed to handle large data volumes efficiently. Always write test methods that validate your code’s behaviour with bulk operations, such as inserting, updating, or deleting multiple records at once. This will ensure your triggers, batch jobs, and other logic perform efficiently and do not exceed governor limits.
9. Use @TestVisible Annotation for Testing Private Methods
When you need to test a private method or variable within an Apex class, use the @TestVisible annotation. This annotation allows you to expose private methods or variables to your test classes without making them globally accessible. Use @TestVisible wisely to maintain code encapsulation while ensuring that all parts of your code are properly tested.
10. Utilise Test Data Factories
Test Data Factories are utility classes that generate Test data for multiple Test classes. A Test Data Factory centralises the logic for creating records, allowing you to easily maintain and reuse test data creation methods across different test classes. This reduces redundancy, promotes consistency, and makes your tests easier to manage.
11. Use @testSetup Annotation to Create Common Test Data
The @testSetup annotation is used within a single Test class to create common test data that is shared among all test methods in that class. This method is executed once before any test methods run, which makes it ideal for setting up test data that multiple tests need.
12. Use System.runAs to Test with Different User Contexts
The System.runAs method in Apex allows you to execute test code under the context of a specific user or profile. This is especially useful when you need to test your code against different permission sets, roles, or sharing settings. It helps you ensure that your code behaves correctly across different user scenarios and adheres to the organisation’s security and sharing rules.
Learn more Apex Test Class Best Practices.
Conclusion
By incorporating these 12 tips into your Apex unit testing strategy, you can improve the reliability, scalability, and maintainability of your Salesforce applications. From managing code storage limits and mock callouts to writing high-quality tests for bulk operations and using different annotations, these best practices will help you make the most of Salesforce’s powerful testing framework. I hope this 12 Apex Unit Test Tips Every Salesforce Developer Should Know post would be helpful for you.
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