A Comprehensive Guide To Best Practices For Test Class In Salesforce

Businesses that use Salesforce need to be sure whether the Apex code is working properly or not. Why? Because Salesforce development relies heavily on it. Test classes are very important here. These classes are a requirement for 

• Moving code into production
• Preventing bugs
• Maintaining quality
• Keeping systems scalable

In Salesforce, a requirement of cover at least 75% of the Apex code with test classes before deployment. But the thing here is more demanding. Simply reaching this percentage is not enough. Organisations must follow best practices for test classes in Salesforce to build reliable and long-lasting Salesforce projects.

This guide explains what test classes are, why they matter, and the best practices every organisation should adopt.

Test Class in Salesforce

A test class in Salesforce is an Apex class created to test other code, such as triggers, methods, or classes. Developers use the @isTest keyword to mark test classes and test methods. These classes include assert statements to check whether the code produces the expected result.

Here’s a simple example:

@isTest

private class MyTestClass {

    @isTest

    static void testMethod1() {

        // Test logic here

        System.assertEquals(1, 1);

    }

}

By running these tests, businesses can confirm their Salesforce code behaves correctly under different scenarios.

Why Best Practices for Test Class in Salesforce Matter

Meeting Salesforce’s 75% requirement might help with deployment, but it doesn’t guarantee reliable operations. If test classes are poorly written, bugs can still slip into production.

For businesses, this means:

• Broken workflows and processes
• Incorrect customer data
• Higher support and maintenance costs
• Lower user trust in Salesforce

Following best practices for test class in Salesforce ensures the system runs smoothly, scales well, and saves money in the long term.

Best Practices for Test Class in Salesforce

Let’s break down the most important practices.

1. Use @isTest Annotation

Always prefix test classes and methods with @isTest. It ensures Salesforce recognises the code as test code and excludes it from organisation limits.

2. Avoid Org Data – Generate Test Data

Don’t depend on real data from the Salesforce org. Instead, create your own test data within the test class. For example:

Account testAcc = new Account(Name = ‘Test Account’);

insert testAcc;

This makes the test independent and reliable.

3. Use Test Data Factory Classes

Instead of writing test data again and again, create a Test Data Factory class. It builds reusable records like Accounts, Contacts, or Opportunities.

Example:

public class TestDataFactory {

    public static Account createAccount() {

        Account acc = new Account(Name = ‘Test Acc’);

        insert acc;

        return acc;

    }

}

4. Avoid Hardcoding IDs

Hardcoding RecordType IDs or system IDs causes errors across environments. Instead, query them dynamically.

5. Name Methods Clearly and Structure Them Well

Good test methods follow a clear structure:

• Setup test data
• Execute the logic
• Assert the results

Example: testLeadConversion_Success() is much clearer than test1().

6. Keep Tests Independent

Each test method should run on its own. If one fails, it should not cause another to fail. This makes troubleshooting easier.

7. Use Assertions

Assertions are the heart of testing. Use System.assert() and System.assertEquals() to verify that outcomes match expectations.

8. Cover Positive, Negative, and Edge Cases

A strong test class doesn’t just check if code works under normal conditions. It also tests what happens when input is invalid, null, or in bulk.

9. Test with Bulk Data

Salesforce is designed to process many records at once. Always test with bulk data (for example, inserting 200 records) to ensure the code handles large volumes.

10. Go Beyond 75% Coverage

Don’t stop at the minimum. Aim to test all if-else conditions, loops, and exception handling blocks. This ensures no hidden bugs reach production.

Creating Test Data the Right Way

Test data is the foundation of strong test classes. Here’s how to do it right:

1. Insert mock records (Account, Contact, Opportunity).
2. Build relationships correctly (e.g., Contact linked to Account).
3. Use a Test Data Factory to reuse record creation.
4. Avoid hardcoding IDs—query them dynamically.

This approach keeps tests consistent and environment-independent.

Additional Tips for Reliable Test Classes

• Respect governor limits: Even though test classes have higher limits, write efficient code.
• Test exceptions: Validate error handling to avoid surprises in production.
• Keep tests environment-independent: Don’t rely on org-specific settings.
• Promote reusability: Reuse setup logic through helper classes or utility methods.

Business Value of Following Best Practices

For organisations, following best practices for test class in Salesforce translates into:

• Higher reliability: Stable deployments with fewer bugs.
• Lower costs: Less rework and reduced maintenance.
• Scalability: Code ready to handle business growth.
• User trust: Employees and customers rely on Salesforce with confidence.

Conclusion

A test class in Salesforce is not just a checkbox for deployment. It is a safeguard for quality, scalability, and trust. By following the best practices for test class in Salesforce—like using @isTest, generating test data, covering all scenarios, leveraging test data factories, and avoiding hardcoded IDs—organisations can strengthen their Salesforce projects.

The goal isn’t just to reach 75% coverage. It is to ensure that Salesforce remains reliable, cost-effective, and ready to grow with your business.