Decisions are the controls that can control the program flow after evaluating the full expression. For MC/DC it is required, that each condition has to affect the outcome independently. With the above test (all are 0 or all are 1), we ignore the fact, that c-value doesn’t matter if a and b are 0, or, that b-value doesnt matter if a and c are 1.
All these methods focus on covering the most important combinations. It is very much similar to decision coverage, but it offers better sensitivity to control flow. For instance, path coverage implies decision, statement and entry/exit coverage.
Statement Coverage
Decision coverage implies statement coverage, because every statement is part of a branch. Generally in any software, if we look at the source code, there will be a wide variety of elements like operators, functions, looping, exceptional handlers, etc. Based on the input to the program, some of the code statements may not be executed.
Here we are taking two different scenarios to check the percentage of statement coverage for each scenario. White box testing is a software testing technique that involves testing the internal structure and workings of a software application. The tester has access to the source code and uses this knowledge to design test cases that can verify the correctness of the software at the code level. In order to ensure complete Condition coverage criteria for the above example, A, B and C should be evaluated at least once against “true” and “false”. And for each alteration of your code, it verifies if the test actually fails. This is good indicator of the quality of your test suite and ensures that code is not just covered but your tests for the code are actually valid.
Code coverage
Some of the most basic are the percentage of program subroutines and the percentage of program statements called during execution of the test suite. Code coverage is a measure which describes the degree of which the source code of the program has been tested. It is one form of white box testing which finds the areas of the program not exercised by a set of test cases.
- Regarding terminology, I don’t have a single source handy that uses the exact terms “basic condition coverage” and “multiple condition coverage”.
- There are also some sorts of defects which are affected by such tools.
- The meaning of this depends on what form(s) of coverage have been used, as 67% branch coverage is more comprehensive than 67% statement coverage.
- However for MCDC the above test cases are not sufficient because in MCDC each Boolean variable should be evaluated to TRUE and FALSE at least once and also affect the decision outcome.
- Let’s understand this with an example, how to calculate statement coverage.
- But overall if you see, all the statements are being covered by both scenarios.
It helps to measure fractions of independent code segments and to find out sections having no branches. Condition Coverage or expression coverage is a testing method used to test and evaluate the variables or sub-expressions in the conditional statement. The goal of condition coverage is to check individual outcomes for each logical condition. Condition coverage offers better sensitivity to the control flow than decision coverage.
Another handy way of filling in the decision table is with the use of the so called “Gray-code”. Let’s understand this with an example, how to calculate statement coverage. For example, multiple condition coverage my test report points out that on an if-condition that checks two boolean flags, it insists that all 4 possible combinations have to be checked before 100% coverage is attained.
White box testing is also known as structural testing or code-based testing, and it is used to test the software’s internal logic, flow, and structure. The tester creates test cases to examine the code paths and logic flows to ensure they meet the specified requirements. White box testing techniques analyze the internal structures the used data structures, internal design, code structure, and the working of the software rather than just the functionality as in black box testing. It is also called glass box testing or clear box testing or structural testing. White Box Testing is also known as transparent testing or open box testing.
To satisfy condition coverage, each Boolean expression X,Y and Z in above statement should be evaluated to TRUE and FALSE at least one time. In most cases, code coverage system gathers information about the running program. It also combines that with source code information to generate a report about the test suite’s code coverage. Fault injection may be necessary to ensure that all conditions and branches of exception-handling code have adequate coverage during testing.
The resulting output is then analyzed to see what areas of code have not been exercised and the tests are updated to include these areas as necessary. Combined with other test coverage methods, the aim is to develop a rigorous, yet manageable, set of regression tests. Percentage of combinations of all single condition outcomes within one and the same operator that have been tested by a set of tests. 100% multiple condition coverage presupposes 100% condition determination coverage. C, those two test cases above would still achieve basic condition coverage but would not achieve branch coverage. There is a compound condition, a && b && c, with three basic conditions, a, b and c.