11. Testing

Testing problems usually fall under one of hour categories:

1. Test a real world object
2. Test a piece of software
3. Write test code for a function
4. Troubleshoot an existing issue

What the Interviewer is Looking For:

• Big Picture Understanding:

  • Are you a person who understands what the software is really about?
  • Can you prioritize test cases properly?

• Knowing How the Pieces Fit Together:

  • Do you understand how software works
  • How might it fit into a greater ecosystem

• Organization:

  • Do you approach the problem in a structured manner
  • A good candidate will break down the parts into categories
  • This structured approach will assist in thoroughly creating test cases

• Practicality:

  • Can you actually create reasonable testing plans?

Testing a Real World Object

1. Who will use it and why?
2. What are the use cases?
3. What are the bounds of use?
4. What are the stress/failure conditions?
5. How would you perform the testing?

Testing Software

Manual vs. Automated Testing:

• manual: human interaction with software
• automated: tests performed by scripts or tools to imitate human interaction

Black Box vs. White Box Testing:

• black box testing: using the software “as is” or with “intended privilleges” to test
• white box testing: additional, elevated programmatic access to test individual functions

1. Are we doing Black Box Testing or White Box Testing?
2. who will use it? And Why?
3. What are the use cases?
4. What are the bounds of use?
5. What are the stress conditions / failure conditions?
6. What are the test cases? How would you perform the testing?

Testing a Function

1. Define the test cases
   • What is the normal case?
   • What are the extreme cases?
   • Nulls and “illegal” input
   • Strange input
2. Define the expected result
3. Write test code

Troubleshooting Questions

1. Understand the Scenario
2. Break Down the Problem into testable units or actions
3. Create Specific, Managable Tests