Salesforce Apex Test Class Best Practices: Faster, Reliable Testing Guide

Are your Salesforce tests taking forever to run and failing unpredictably? 🤔 I have been there and have been researching an effective way to solve this; here I am, finally discussing it.

Many developers struggle with slow, unreliable tests due to DML operations. That is why you have this blog to know how you can write fast, reliable tests without database operations.

The Problem with DML in Tests

Let's understand why DML tests are problematic:

1. Performance Issues: Database operations slow down test execution

2. Governor Limits: DML limits can cause test failures

3. Data Dependencies: Tests become dependent on the org data

4. Unreliable results: Tests may pass/fail based on existing data

5. Maintenance Overload: More complex test data setup

This would make us surprised because tests that worked yesterday suddenly fail and become a tremendous blocker, which in turn would lead to hours of debugging instead of building features.

Understanding Test.isRunningTest()

What is Test.isRunningTest()?

• Built-in Salesforce method to detect test context

• Returns true when code runs in test execution

• A simple way to avoid DML during tests

When to Use:

• Conditional DML operations

• Mocking database responses

• Switching between Test and production behaviour

Code Example:

isRunningTest example

Now that we understand what RunningTest is, let's know what can be done better to squash away the above issues -

Let's take it step by step to ensure we approach it correctly -

• Identify DML Operations in your class

• Wrap DML in Conditions using Test.isRunningTest()

• Provide Mock Data for test scenarios

• Write Tests that validate business logic

Benefits of This Approach:

• No external dependencies

• Easy to implement

• Maintains a simple code structure

• Fast test execution

How to Write Effective Test Classes

Test Structure Best Practices:

• Arrange, Act, Assert pattern

• Clear test method names (testMethodName_Scenario_ExpectedResult)

• Test both positive and negative scenarios

• Use meaningful assertions

Essential Test Scenarios:

1. Happy Path: Normal, expected behaviour

2. Edge Cases: Boundary conditions and limits

3. Error Handling: Invalid inputs and exceptions

4. Null Handling: Null and empty inputs

   
   

Code Coverage Tips:

• Aim for meaningful coverage, not just percentages

• Test business logic, not just technical coverage

• Use @TestVisible for testing private methods when needed

Best Practices & Tips

Performance Tips:

• Use static test data when possible

• Avoid unnecessary object creation

• Batch similar test scenarios

• Consider test execution order

Troubleshooting Common Issues

Common Problems & Solutions:

1. "Method does not exist" errors: Check Test.isRunningTest() conditions

2. Null pointer exceptions: Ensure mock data is properly initialised

3. Assertion failures: Verify expected vs actual values

4. Coverage issues: Add tests for all code paths

   
   

Debugging Tips:

• Use System.debug() for troubleshooting

• Check test execution logs

• Verify test data setup

• Use the developer console for debugging

Conclusion & Next Steps

Key Takeaways:

• DML-free testing leads to faster, more reliable tests

• Simple approaches work for most scenarios

• Test.isRunningTest() is your best friend

• Focus on business logic, not database operations

What's Next:

• Try implementing it in your current projects

• Explore the Stub API for complex scenarios

• Consider test automation and CI/CD integration

• Share knowledge with your team

Watch the video below for more details.

Start with one test class and see the difference, and share your testing patterns. Don't forget to subscribe and follow for more Salesforce development tips.