Development
Salesforce Test Classes Interview Questions and Answers Experienced
1. What is a Test Class in Salesforce?
Ans: A Test Class is an Apex class used to verify that Apex code works as expected. It helps ensure code quality and enables deployment to production.
2. Why are Test Classes important in Salesforce?
Ans: Test Classes ensure code correctness, prevent regression, meet Salesforce deployment requirements (75% code coverage), and help catch bugs early.
3. What is code coverage in Salesforce testing?
Ans: Code coverage measures the percentage of Apex code executed by test methods. Salesforce requires at least 75% coverage to deploy Apex code to production.
4. How do you write a simple test method?
Ans:
Annotate a method with @isTest and write test logic that creates test data, executes the code under test, and asserts expected results.
5. Can test methods access real data in Salesforce?
Ans:
By default, test methods run in an isolated context and do not see real org data unless annotated with @isTest(SeeAllData=true), which is discouraged.
6. What is the use of Test.startTest() and Test.stopTest()?
Ans: They reset governor limits within test methods and allow asynchronous processes to run synchronously during testing.
7. Scenario: You want to test a trigger that runs when an Account is inserted. How do you write the test?
Ans: Create a test method that inserts an Account record, then assert expected outcomes such as field updates or related records.
8. How do you test Batch Apex classes?
Ans:
Call Database.executeBatch() inside a test method between Test.startTest() and Test.stopTest() to run the batch synchronously.
9. What is a Test Data Factory?
Ans: A Test Data Factory is a helper class that creates reusable test data for use in multiple test methods.
10. Scenario: Your code uses a callout to an external service. How do you test this?
Ans:
Implement an HttpCalloutMock class to simulate the callout response and use Test.setMock() in the test method.
11. Can you test negative or exception scenarios in Apex test classes?
Ans:
Yes, use try-catch blocks and System.assertThrows() to verify exceptions and error handling.
12. What annotation do you use to mark a class as a test class?
Ans:
Use the @isTest annotation to mark a class or method as a test.
13. How can you ensure your test class covers all branches in your code?
Ans: Write test methods for each logical path, including positive, negative, and boundary conditions.
14. Scenario: You have a method that queries records based on criteria. How do you test this efficiently?
Ans: Create test data with different criteria and assert that the method returns the correct filtered records.
15. What is the maximum number of test methods allowed in a test class?
Ans: Salesforce allows up to 200 test methods per test class.
16. Scenario: You want to test a trigger that updates a related record. How do you validate the update?
Ans:
Query the related record after the trigger execution and use System.assertEquals() to verify the update.
17. How do you test asynchronous Apex like @future methods?
Ans:
Call the future method between Test.startTest() and Test.stopTest() so it runs synchronously during testing.
18. Why should you avoid using @isTest(SeeAllData=true)?
Ans: It makes tests dependent on org data, reducing test reliability and causing unpredictable failures. Creating test data is preferred.
19. Scenario: Your code handles both insert and update operations. How do you write tests?
Ans: Write separate test methods for insert and update scenarios to cover both code paths.
20. How can you improve test execution time?
Ans: Use efficient test data creation, limit unnecessary DML operations, and test only required logic per method.