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, or by using other, less-focused approaches manually, 2) by using data generation tools or 3) it can be retrieved from existing production environment. The data set can consist of synthetic data, but preferably it consists of representative data.
Limitations
Due to privacy rules and regulations all over the world like GDPR, PCI and HIPAA it is not allowed to use privacy sensitive personal data for testing. But anonymized production data may be used as representative data for test and development. You may also choose to generate synthetic data but this comes with its own limitations. It is not always possible to produce enough fake or synthetic 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 Cycletoday. 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.