Salesforce gives developers the ability to precisely customize business logic to meet their needs by utilizing Apex code and triggers. But this authority includes the need to thoroughly evaluate Apex code. Testing guarantees that the code manages exceptions, executes effectively, and doesn’t malfunction when deployed. In this article we will discuss “How Do You Test Custom Apex Code and Triggers?”
Why Is Testing Apex Code Important?
Salesforce requires at least 75% code coverage for Apex classes and triggers before deployment to production. But coverage isn’t everything — robust testing helps you:
-
- Identify and fix bugs early
- Validate business logic and workflows
- Ensure governor limits are not exceeded
- Improve deployment confidence
- Maintain code quality over time
1. Write Test Classes Using Apex
Salesforce runs unit tests using Apex test classes. You need to create a different test class with methods that invoke your custom logic and simulate user actions.
Example
@isTest
private class AccountTriggerTest {
@isTest
static void testAccountInsertion() {
Account acc = new Account(Name=’Test Account’);
insert acc;
System.assertNotEquals(null, acc.Id);
}
}
In the example above, the test method inserts an account record, which in turn fires a trigger. You validate the outcome using System.Assert
2. Use Test.startTest() and Test.stopTest()
Salesforce enforces governor limits, even during tests. Use Test.startTest() and Test.stopTest() to reset limits and isolate the code you want to measure.
Test.startTest();
insert new Contact(LastName=’Test’, AccountId=acc.Id);
Test.stopTest();
This helps you ensure your logic runs within platform limits.
3. Test for Positive and Negative Scenarios
You should always test for:
-
- Positive flow (valid inputs)
- Negative flow (missing fields, wrong data)
- Bulk scenarios (insert/update/delete on multiple records)
- Edge cases (empty strings, null values, maximum field lengths)
Testing triggers in bulk is essential because Salesforce often processes records in batches.
To avoid repeating data creation in every test method, use @testSetup to create test records once and reuse them across methods
@testSetup
static void setupData() {
Account acc = new Account(Name=’Setup Account’);
insert acc;
}
This boosts performance and makes tests easier to maintain.
4. Use @testSetup for Reusable Data
To avoid repeating data creation in every test method, use @testSetup to create test records once and reuse them across methods.
@testSetup
static void setupData() {
Account acc = new Account(Name=’Setup Account’);
insert acc;
}
This boosts performance and makes tests easier to maintain.
5. Isolate Tests from Real Data
All tests are automatically executed by Salesforce in an isolated test context, which prevents test methods from accessing actual organization data. SeeAllData=true can be used if necessary, however it is not advised. To prevent dependencies and flakiness, create all test data programmatically inside the test itself.
6. Assert the Expected Results
A lot of developers make the mistake of focusing solely on code coverage. Rather, make use of assertions to confirm that the result matches to the expected behavior.
System.assertEquals(‘Test Account’, acc.Name);
Asserting values verifies that your logic performs correctly, not just that it executes.
7. Mock Callouts and Async Processes
Use HttpCalloutMock to mimic the response if your Apex class makes HTTP callouts. To make sure async processes, such as @future or Queueable, run within the test context, call them inside Test.startTest() and Test.stopTest().
8. Use TestUtils or Helper Classes
Create a Test Utility class that generates helpful methods, reusable triggers, or dummy data to prevent duplication. This makes the code easier to read and maintain.
Best Practices at a Glance:
-
- Write separate test classes for each trigger/class
- Cover all DML operations (insert, update, delete, undelete)
- Use assertions for expected behavior
- Keep tests fast and isolated
- Avoid hardcoded IDs or external dependencies
- Aim for 90%+ meaningful code coverage
Conclusion
Testing custom Apex code and triggers is not just a Salesforce requirement —it’s also a best practice that keeps your organization scalable, stable, and prepared for deployment. You may confidently deliver high-quality code by creating intelligent test classes, managing edge cases, and asserting results.
You’ll save many hours troubleshooting tomorrow if you take the effort to test thoroughly today.
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