Function test of the system test method

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Function Testing, also known as Correctness testing, checks whether the software's functions meet the specifications. Correctness is the most important quality factor in software, so testing is also the most important.

The basic method is to construct some reasonable input and check whether the expected output is obtained. This is an enumeration method. The tester must try to reduce the number of enumerations, otherwise the test investment will be too large. The key is to find the equivalence zone, because in the equivalence zone, you only need to test it once with any value. The concept of equivalence zone can be expressed as follows: Note (a, B) is an equivalence zone of proposition f (x). In (a, B), take X1 for testing. If F (X1) is incorrect, f (x) fails in the entire (a, B) interval. If F (X1) is correct, f (x) is correct throughout (A, B. The above test method is called equivalent test. It comes from people's intuition and experience and can get twice the result with half the effort.

Another effective test method is boundary value testing. That is, the boundary values of the defined domain or the equivalence zone are used for testing. Because programmers are easy to neglect the boundary, the program also "likes" errors at the boundary value. For example, a program that tests the square root function. Intuitively, the input equivalence zone must be (0, 1) and (1, + ∞ ). X = 0. 5 and x = 2. 0. Take x = 0 and x = 1 for the Boundary Value test.

There are some complex programs that make it difficult to find the equivalence zone and Boundary Value Based on intuition and experience. In this case, enumeration testing is quite difficult.

 

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