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Testing Methods

Software testing methods are traditionally divided into white- and black-box testing. Further, these two approaches describe the point of view that a test engineer takes while designing test cases.

White-box Testing

White-box testing refers to a method of testing software that tests internal structures of an application. Moreover, white-box testing incorporates an internal perspective of the system, as well as programming skills to design test cases. The tester chooses inputs to exercise paths through the code and determine the appropriate outputs.

This testing method tests paths within a unit, paths between units during integration, and between subsystems during a system-level test. Though this method of test design can uncover many errors or problems, it might not detect unimplemented parts of the specification or missing requirements.

White-box test design techniques include:

• Control flow testing
• Data flow testing
• Branch testing
• Path testing

White box testing is when the tester has access to the internal data structures and algorithms including the code that implements these. things.

Black-Box Testing

Black-box testing refers to a method of software testing that tests the functionality of an application as opposed to its internal structures or workings. Specific knowledge of the application’s code/internal structure and programming knowledge, in general, is not required. Moreover,it uses external descriptions of the software, including specifications, requirements, and design to derive test cases. These tests can be functional or non-functional, though usually functional. The test designer selects valid and invalid inputs and determines the correct output. There is no knowledge of the test object’s internal structure.

This method of test typically comprises most if not all testing at higher levels, but can also dominate unit testing as well.

Black box testing treats the software as a “black box”—without any knowledge of the internal implementation. Black box testing methods include equivalence partitioning, boundary value analysis, all-pairs testing, fuzz testing, model-based testing, traceability matrix, exploratory testing, and specification-based testing.

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