3. Describe the Concepts of Test-Driven Development 200-901 Practice Questions (Page 6)

Questions 26–30

1. 26application · medium

   A developer is testing a function that sends a configuration to a device via SSH. The function uses a library that establishes an SSH connection. To test the function without connecting to a real device, what should the developer use?

   • AA stub that returns a fixed response but does not record calls
   • BA test that skips the SSH call and assumes it works
   • CA real SSH connection to a lab device
   • DA mock object for the SSH library that records the commands sent
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2. 27application · medium

   A developer is writing a unit test for a function that sends a configuration change to a network device via NETCONF. The function should return True if the device accepts the change. To test this without a real device, what is the best approach?

   • AUse a real device in a lab to test the function
   • BCreate a stub that always returns False to verify error handling
   • CUse a mock object that simulates the NETCONF session and returns a success response
   • DWrite a test that checks the function's source code for correct NETCONF usage
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4. 28foundation · easy

   Why is it safe to refactor code when using test-driven development?

   • ABecause the code is already perfect
   • BBecause refactoring is done by a separate team
   • CBecause refactoring does not affect the code
   • DBecause the tests will catch any behavior changes
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5. 29expert · medium

   A developer is writing unit tests for a function that retrieves device inventory from a REST API. The function uses a client class that handles authentication and HTTP requests. To test the function in isolation, what is the best approach?

   • AUse a real REST API endpoint in a test environment
   • BTest the function by calling the API and verifying the response
   • CMock the client class to return a predefined inventory response
   • DStub the HTTP library to return a fixed response
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6. 30expert · medium

   A developer is adding a new feature to a network automation script. They write a test that fails, then implement the feature, and the test passes. However, they realize that the implementation is not optimal and could be improved. What should the developer do?

   • ARefactor the implementation and re-run the test suite
   • BCommit the code as is and refactor later
   • CWrite a new failing test for the improved implementation
   • DRevert the implementation and start over
   Reveal Solution Discussion Select an answer first