3. Describe the Concepts of Test-Driven Development 200-901 Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   A network automation engineer is developing a Python function that validates SNMP community strings. Following TDD, the engineer writes a test that expects the function to return False for a community string that contains a space. The test fails because the function does not exist yet. What is the next step in the TDD cycle?

   • AWrite additional tests for edge cases before coding
   • BCommit the failing test to the repository to document expected behavior
   • CImplement the minimum code needed to make the test pass
   • DRefactor the existing code to improve its structure
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2. 2application · medium

   A CI pipeline includes a coverage gate that fails if coverage drops below 80%. A developer adds a new module but does not write tests for it, causing coverage to drop to 75%. What is the best action for the developer?

   • ALower the coverage threshold in the pipeline to allow the merge
   • BRemove the coverage gate from the pipeline
   • CMerge the code and address coverage later
   • DWrite unit tests for the new module to bring coverage back above the threshold
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4. 3application · easy

   A team developing a Python library for network device configuration is adopting TDD. They want to reduce the number of defects that reach production. Which practice is most directly aligned with TDD's benefit of reducing defects?

   • ARunning a linter on every commit to enforce coding style
   • BDeploying to a staging environment and testing manually
   • CWriting a failing test for each new feature before implementing the feature
   • DPerforming a manual code review before merging each pull request
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5. 4expert · medium

   A developer has a passing test suite for a module that parses device logs. The module has a function that is 100 lines long and contains several nested conditionals. The developer wants to refactor it to improve readability. What is the safest way to refactor?

   • ABreak the function into smaller functions and re-run the test suite after each change
   • BRefactor the function and update the tests to match the new structure
   • CLeave the function as is because the tests pass
   • DRewrite the function from scratch and run the tests once at the end
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6. 5foundation · easy

   In a unit test, which of the following is an example of a valid assertion?

   • Ainput("Enter expected result: ")
   • Bprint(add(2, 3))
   • Cimport unittest
   • DassertEqual(add(2, 3), 5)
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