Test data is data which has been specifically identified for use in tests, typically of a computer program.
Some data may be used in a confirmatory way, typically to verify that a given set of input to a given function produces some expected result. Other data may be used in order to challenge the ability of the program to respond to unusual, extreme, exceptional, or unexpected input.
Test data may be produced in a focused or systematic way (as is typically the case in domain testing), or by using other, less-focused approaches (as is typically the case in high-volume randomized automated tests). Test data may be produced by the tester, or by a program or function that aids the tester. Test data may be recorded for re-use, or used once and then forgotten.
It is not always possible to produce enough data for testing. The amount of data to be tested is determined or limited by considerations such as time, cost and quality. Time to produce, cost to produce and quality of the test data, and efficiency.
Domain testing is a family of test techniques that focus on the test data. This might include identifying common or critical inputs, representatives of a particular equivalence class model, values that might appear at the boundaries between one equivalence class and another, outrageous values that should be rejected by the program, combinations of inputs, or inputs that might drive the product towards a particular set of outputs.
Test data generation
Software testing is an important part of the Software Development Life Cycle today. It is a labor-intensive and also accounts for nearly half of the cost of the system development. Hence, it is desired that parts of testing should be automated. An important problem in testing is that of generating quality test data and is seen as an important step in reducing the cost of software testing. Hence, test data generation is an important part of software testing.
Popular Open Source Data Generators
- "The evaluation of program-based software test data adequacy criteria", E. J. Weyuker, Communications of the ACM (abstract and references)