Test Class in Salesforce: Code Coverage, Examples and Best Practices
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Last Update :25 June 2026
Publish Date :13 April 2026
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This blog explains Salesforce test classes with clear examples and code coverage concepts. It helps you understand how to write effective test classes and improve overall test coverage. You’ll also learn best practices to ensure reliable and deployable Salesforce code.
In Salesforce development, coding that is solid and scalable may be only one part of the process; however, it becomes necessary to ensure that it works effectively in various conditions without any interference in the already working functionalities. This is exactly where Test Classes in Salesforce become quite handy. If you are learning through salesforce courses online, you’ll notice that test classes are one of the most important foundational topics covered in depth.
Regardless of your experience level, learning about test classes is vital both when deploying code and to ensure the quality of your code remains at a high standard. Salesforce mandates thorough testing, meaning that writing test classes is necessary before deploying Apex code to the live environment. Here’s where you’ll find all there is to know about the test class in Salesforce from its code coverage, sample tests, to do’s and don’ts.
What Exactly Is a Test Class in Salesforce?
The Test Class in Salesforce is basically an Apex class which is designed to test the behavior of another Apex class or trigger. The Test Class technically helps you in the verification of whether your business logic behaves as expected under different circumstances. You can basically create test classes by adding the @isTest annotation to them and they do not count your APex code governor limits.
Key Features of Test Classes:
- Uses the @isTest annotation.
- Used for testing Apex code.
- Doesn’t affect any data in production.
- Deployment in the production environment requires them.
The developers have to validate their code using the test cases prior to deployment as Salesforce employs the test driven model.
Understanding Code Coverage in Salesforce
Code coverage is the extent to which an Apex code is tested. Salesforce mandates that there should be at least 75% code coverage for code deployment.
Formula for Code Coverage:
(Number of lines executed by test classes / Total number of lines in Apex code) × 100
Important Points:
- Minimum Coverage of 75%
- Coverage is required for all triggers
- More Coverage leads to More Reliability
Code Coverage is not only required for Deployment but also makes sure that your Application functions well in practical life.
Why Test Classes Are Crucial in Salesforce Development
Test Classes Are Not Optional; They Are a Necessity for Maintaining Your Stable and Scalable Salesforce Application
1. Necessary For Deployment
The deployment process does not occur unless there are test classes.
2. Increases Quality of Code
This process helps validate your code logic and reduces errors.
3. Assures the stability of the System.
You can easily find any problem before it can cause any disruption in the program.
4. Facilitates of Future Enhancements
All the previous test cases remain valid with any future modifications in the system.
5. Grows Developer's Confidence
Developers can modify the system code without worrying about causing any problems.
Step-by-Step Guide to Writing a Test Class in Salesforce
It can be difficult to create a test class, but by following the steps below, it becomes easy.
Step 1: Use @isTest Annotation
Every test class must include the @isTest annotation.
@isTest
public class AccountTestClass {
}
Step 2: Create Test Data
You cannot rely on existing org data. Always create your own test data.
Account acc = new Account(Name = 'Test Account');
insert acc;
Step 3: Call the Method to Be Tested
Invoke the Apex class or trigger you want to test.
Step 4: Use Test.startTest() and Test.stopTest()
These methods help simulate real execution context.
Test.startTest();
// Call method
Test.stopTest();
Step 5: Add Assertions
Assertions verify if the expected output matches the actual result.
System.assertEquals('Test Account', acc.Name);
Real Example of a Test Class in Salesforce
Let’s understand with a simple example.
Apex Class:
public class AccountService {
public static Account createAccount(String name) {
Account acc = new Account(Name = name);
insert acc;
return acc;
}
}
Test Class:
@isTest
public class AccountServiceTest {
@isTest
static void testCreateAccount() {
Test.startTest();
Account acc = AccountService.createAccount('Test Account');
Test.stopTest();
System.assertNotEquals(null, acc.Id);
System.assertEquals('Test Account', acc.Name);
}
}
Explanation:
- Test procedure verifies creation of an account
- Tests ensure proper data
- Guarantees that logic functions as intended
It is a simple yet efficient means of accomplishing code coverage.
Best Practices for Writing Test Classes in Salesforce
To ensure that your test classes are efficient and scalable, consider following these proven best practices:
1. Strive for More than 90% Code Coverage
Though 75% code coverage is mandatory, it is best to always strive for greater reliability.
2. Implement @testSetup Method
It will allow creating reusable test data.
@testSetup
static void setupData() {
Account acc = new Account(Name='Setup Account');
insert acc;
}
3. Do Not Hardcode Data
Dynamic data will improve flexibility.
4. Test Valid Inputs and Invalid Inputs
- Positive scenario
- Negative scenario
- Edge case scenario
5. Use System.Assert Correctly
Assertions check that your logic is functioning properly.
6. Perform Bulk Testing
Always bulk test your code with multiple records.
7. Use Test.startTest() and Test.stopTest()
Improves governance limits testing accuracy.
8. Never Use SeeAllData=True
Always test without relying on organization data.
9. Make Sure Tests Are Independent
Make sure that each of your tests is independent.
10. Keep It Readable
Test classes need to be easily readable.
If you want to seriously study the above concepts, it might be wise to sign up for a Salesforce course online.
Advanced Techniques to Improve Test Class Efficiency in Salesforce
Although it is quite important to write simple tests, along with that it is even more necessary is learning more sophisticated strategies which leads to better quality code and faster execution along with easier maintenance.
Here are some of the techniques that can be used:
1. Utilizing Test Data Factories
Rather than always generating test data again in each test class, programmers make use of a Test Data Factory. This is an Apex class used for generating test data dynamically.
Benefits:
- Reduces code duplication
- Improves maintainability
- Makes test classes cleaner
Example:
public class TestDataFactory {
public static Account createAccount(String name) {
Account acc = new Account(Name = name);
insert acc;
return acc;
}
}
You can call this method in multiple test classes, making your code modular and efficient.
2. Testing with Bulk Data
Salesforce operates in bulk for any data operation (import, API requests, etc.) in practical life cases. If your test class is written to test single records only, your code will break in production.
Best Practices:
Test using multiple records every time.
List accList = new List();
for(Integer i = 0; i < 200; i++) {
accList.add(new Account(Name = 'Test ' + i));
}
insert accList;
This ensures your code handles bulk operations efficiently.
3. Testing Asynchronous Apex
Asynchronous processes supported by Salesforce include the following:
- Future methods
- Batch Apex
- Queueable Apex
This needs special care while testing.
Example:
Test.startTest();
MyFutureClass.myFutureMethod();
Test.stopTest();
Test.stopTest() ensures all asynchronous operations are completed before assertions are executed.
4. Mocking Callouts Using Test Classes
If your Apex code makes external API callouts, you cannot call real APIs during testing. Instead, Salesforce provides mock callouts.
Key Concept:
Use HttpCalloutMock to simulate API responses.
Benefit:
- Allows testing integrations
- Ensures test reliability
- Avoids dependency on external systems
5. Governor Limits Testing
Salesforce enforces various restrictions on SOQL query, DML operations, etc. Writing an efficient test class guarantees that your code doesn’t breach these restrictions. The Test.startTest() method helps you check your business logic by resetting the governor limits.
6. Maintaining Test Class Performance
As the scope of your project increases, the performance of tests may start affecting deployments. To overcome this problem:
- Limit the amount of test data
- Avoid using DML statements unnecessarily
- Reuse the setup methods of tests
- Optimize code within tests
- Effective tests lead to fast deployments.
7. Code Coverage vs Code Quality
While many novices concentrate solely on reaching 75% test coverage, expert programmers care about good-quality code.
Good Test Class = 75% Test Coverage + Good Assertions + Practical Scenarios
Rather than merely increasing the coverage percentage, make sure that:
- All logic flows are tested
- All edge cases are covered
- All business scenarios are tested
Common Mistakes to Avoid in Salesforce Test Classes
Experienced developers also make errors while creating test classes. Some of the most common errors include:
1. No Asserts in Tests
If you don’t use asserts, you cannot validate the test results.
2. Insufficient Coverage
Coverage level above 75% must be reached.
3. Using Real Organization Data
The use of SeeAllData=true is discouraged.
4. No Testing for Bulk Data
You need to check whether your code works fine with more than one record.
5. Complicated Tests
Keep test classes simple.
6. Lack of Negative Cases Testing
Make sure that your class can handle negative scenarios.
7. ID Hardcoding
You cannot use hard-coded IDs, as they change across the environments.
Conclusion
Unit testing classes are the core of Salesforce programming. They make sure that your Apex class code can function properly in different environments and conditions. Not only does one need to understand the concept of code coverage in Salesforce but also follow certain best practices to learn how to write good test classes.
By taking some structure, applying assertions, and not making certain mistakes, one can develop a very efficient application that works without errors.Test class learning should be considered an initial step towards developing a career in Salesforce, as many institutes such as Srijan Institute can provide practical training in this regard.
FAQs Related to Test Class in Salesforce
Q1. What is the minimum code coverage required in Salesforce?
A. The minimum code coverage required to deploy Apex code in Salesforce is 75%.
Q2. How can we write a test class in Salesforce?
A. We can write a test class by applying @isTest annotation to the test class or method, generating test data, running the methods, and verifying the outputs with assertions.
Q3. What are the best practices in writing test classes in Salesforce?
A. Using reusable data, considering all test scenarios, avoiding hardcoded values, and achieving higher code coverage are best practices while writing test classes.
Q4. Is it possible to deploy code without test classes in Salesforce?
A. It is not possible to deploy code without test classes in Salesforce.
Q5. What is the purpose of @isTest annotation in Salesforce?
A. @isTest annotation indicates that the class or method should be tested only and does not contribute to code size limits in Salesforce.
Madiha
Content Writter
I'm Pratikha — an experienced SAP architect who's spent over a decade transforming businesses across banking, retail, and transport industries. Having led 15+ end-to-end SAP implementations worth £50M+, I've guided organisation transforming businesses across banking, retail, and transport industries. Having led 15+ end-to-end SAP implementations worth £50M+, I've guided organisation...
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