(the poorest methodology is random input testing)

Transcription

1 Functional Testing

2 Complete Testing is not all possible We may like to reduce this incompleteness as much as possible. What we are looking for is a set of thought processes that allow us to select a set of data more intelligently. (the poorest methodology is random input testing)

3 What is Functional Testing? Functional Testing (also know as Behavior testing) is based on the Functionality of the program. It is involves only observation of the output for certain input values. There is no attempt to analysis the code, which produces the output Functional Testing also referred as Black Box Testing Input domain Ouput domain Input test data System Under test Output test data

4 Techniques used to design Test Cases for Functional Testing Boundary Value Analysis Equivalence Class Testing Decision Table Base Testing Cause Effect Graphing Technique Special Value Testing

5 Boundary Value Analysis (1) Experience show that test cases that are close to boundary condition have higher chances of detecting an error. Boundary condition means: an input value may be on the boundary, jut below the boundary (upper side) or just above the boundary (lower side). Based on Single Fault assumption

6 Boundary Value Analysis (2) Uses input variable values at their: Minimum 400 Just above minimum Nominal value Just Maximum Maximum Test cases are obtained by Combine values of one variable with the nominal values of remain variables Repeat above step until all variable are traversed There are 4n+1 test cases for a program has n variables

7 Boundary Value Analysis (3) Assume we have a program with two input variables, which have any value from 100 to 300 Test cases are: (200,100), (200,101), (200, 200), (200, 299), (200, 300), (100, 200), (101, 200), (299, 200), (300, 200) Generate Test cases for the program that determination of the nature of roots of quadratic equation. Values of coefficients are ranged from 0 to 100. The program may outputs one of following words: Not a quadratic equation, Real Root, Imaginary Root, Equal Root. [Show Result]

8 Robustness Testing (1) The extension of boundary value analysis We would like to see what happen when the extreme values are exceeded Total test cases: 6n + 1 Robustness test cases 400 for 2 variables x, y with 300 range [100,200]

9 Robustness Testing (2) (200,99), (200,100), (200,101) (200,200), (200,299), (200,300) (200,301) (99,200), (100,200),(101,200) (299,200),(300,200),(301,200)

10 Worst-Case Testing Reject single fault assumption theory of reliability We would like to see what happen when more than one variables has an extreme value. Require more effort Total test cases for Worst-case testing: 5 n Example:

11 Equivalence Class Testing(1) Input domain of a program is partition into a finite number of equivalence classes The equivalence classes are identified by taking each input condition and partitioning it into valid and invalid classes Generate the test cases using the equivalence classes. This performed by writing test cases covering all the valid equivalence classes. Then a test case is written for each invalid equivalence class (no test case contain more than one invalid class

12 Equivalence Class Testing(2) Example: For a program that supposed to accept any number between 1 and 99: There are four equivalence classes form input side Any number between 1 and 99 is valid input Any number less than 1 (invalid input) Any number greater than 99 (invalid input) If it not a number, it should not be accepted The test cases are: (50), (-1), (100) Example: 1. Generate test cases for the program that accept any three integer numbers in range [ ] 2. Generate test cases for the program that determine the nature of root of a aquaratic equation (a, b, c are in range [0..100].

13 Equivalence Class Testing(3) Most of the time, equivalence class testing defines classes of the input domain. However, equivalence classes should also be defined for output domain.

14 Decision Table Based Testing (1) Useful for describing situation in which number of combinations of actions are taken under varying sets of condition Four portions of decision table: Conditions stub, Action stub, Condition entries, Action entries. Condition Stub Action stub Entry c 1 True False c 2 True False True False c 3 True False True False True False True False a 1 X X X a 2 X X X a 3 X X a 4 X X X

15 Decision Table Based Testing (2) To identify test cases with decision tables we interpret condition as input, and action as output. Example: Decision table for triangle program:

16 Decision Table Based Testing (3) The test cases derived from Decision table:

17 Ad Hoc Testing Testing carried out using no recognized test case design technique. Also known as Special value testing. Mostly intuitive and least uniform. It occurs when the tester uses domain knowledge experience and information about soft spots to derive test cases. Dependent on the abilities of the tester. Other terms: hacking, out-of-box testing