Test Types

Definition:
Black-box testing is a method of software testing that focuses on what the software does, without any knowledge of the internal code or logic.

Key points:

• The tester only knows the inputs and expected outputs.
• Tests are based on requirements and functionality.
• Common techniques: boundary value analysis, equivalence partitioning, state transition testing.
• Used for system testing, acceptance testing, and often integration testing.

Example:
Testing a login form by entering valid and invalid usernames/passwords to see if the system behaves correctly, without knowing how the authentication is implemented internally.

Definition:
White-box testing (also called clear-box or glass-box testing) is a method where the tester has access to the internal code, and tests are based on the internal logic and structure of the code.

Key points:

• The tester uses knowledge of the source code to design test cases.
• Focuses on code paths, conditions, loops, and branches.
• Common techniques: statement coverage, branch coverage, path testing.
• Often used for unit testing and security testing.

Example:
Testing each possible branch of an if statement in a function to make sure every line of code is executed at least once.