5. Construct a Python Unit Test 200-901 Practice Questions (Page 7)

Questions 31–35

1. 31foundation · easy

   What does code coverage measure in the context of unit testing?

   • AThe time it takes to run the test suite.
   • BThe number of test cases that pass.
   • CThe number of assertions in the test suite.
   • DThe percentage of code lines or branches that are executed by the test suite.
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2. 32application · medium

   A team has a large test suite organized into multiple test modules. They want to create a single test suite that includes only a subset of tests for a specific feature, so they can run just those tests quickly. Which approach should they use?

   • AMove the desired tests into a separate module and run that module directly.
   • BRun all tests with unittest discovery and use the -k flag to filter by test name.
   • CUse the --failfast flag to stop at the first failure.
   • DUse unittest.TestSuite and add the desired test cases, then run the suite with a custom runner.
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4. 33application · easy

   A developer is writing a unit test for a function that validates an IP address. The function should return True for a valid IP and False for an invalid IP. The developer wants to verify that the function returns False for the invalid IP '999.1.1.1'. Which assertion should be used?

   • AassertIn('999.1.1.1', validate_ip('999.1.1.1'))
   • BassertEqual(validate_ip('999.1.1.1'), 'invalid')
   • CassertTrue(validate_ip('999.1.1.1'))
   • DassertFalse(validate_ip('999.1.1.1'))
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5. 34application · medium

   A developer is writing tests for a function that reads a configuration file and returns its contents as a string. The tests should not depend on the actual file system. The developer wants to use a mock to replace the built-in 'open' function. Where should the mock be applied?

   • AIn the tearDown method, creating a mock for the file object
   • BIn the setUp method, assigning a mock to the module's open function
   • CIn the test method, using unittest.mock.patch('builtins.open', mock_open(read_data='config'))
   • DIn the test class definition, using a class attribute to hold the mock
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6. 35expert · medium

   A developer is writing a unit test for a function that parses a syslog message and returns a dictionary with 'severity' and 'message' keys. The function should return None for invalid input. The developer wants to verify that the function returns None for an empty string. Which assertion should be used?

   • AassertIn('', parse_syslog(''))
   • BassertEqual(parse_syslog(''), None)
   • CassertIsNone(parse_syslog(''))
   • DassertFalse(parse_syslog(''))
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