Test Cases

A test case is composed of

• a context
  • the condition or configuration under which the test can be executed
• one or more test inputs
  • action or procedure with input data, such as a method call or a UI interaction
• corresponding test oracles
  • a test oracle consists of
    • expected result (oracle value) of input
    • comparison of the expected result with the actual result

Positive, Negative, and Malicious Tests

• Positive Test
  • deals with only valid inputs
• Negative Test
  • deals with only invalid inputs
• Malicious Test
  • special type of negative test that attempts to break the software
  • e.g. SQL injection tests

To adequately test a program, negative tests usually outnumber positive tests. A ratio of 3:1 is not uncommon.

Test Suites

A test suite is a set of test cases and/or test suites.

It's generally impossible to create a complete test suite that can exhaustively test a real-world program due to its large input space and possible execution paths. The design of a test suite often aims to select representative tests with a certain strategy.

Pass and Fail

A failing test indicates that either:

• the software under test is faulty
• the test case itself is faulty

A passing test doesn't guarantee correct software!