The proceeding steps involve the process of assembling a logical decision making flowchart and to list the results or outcomes of the various decisions instilled in the application’s code. It can most likely have more than one conclusion, as one consistent code execution flow doesn’t need to involve any logical decision to be made. The branch is an optional execution path, whereas a decision is the result of a combination of conditions (i.e. a boolean expression). To achieve 100% condition coverage, your test cases need to demonstrate a true and false outcome for both conditions. For example, a test case where xis equal to 4 demonstrates a true case for both conditions, and a case where x is equal to 7 demonstrates a false case for both conditions.
If the results are unmatched, then the message ‘Your answer is wrong’ will be displayed. Hence this code consists of two possible logical decisions, and testing the scope of this code can be called as the Decision Coverage Testing. I can imagine a system where there are two edges from one statement to the next. In such a case, if one traverses only one edge then they have statement coverage but not branch coverage. For decision coverage compliance with DO-178C, in the Configuration Parameters, set the Structural Coverage Level to Condition Decision for Boolean expressions not containing && or || operators. Statement coverage measures the number of source code statements that execute when the code runs.
Decision Coverage Testing
For example, assignment of the number of days in a month could be achieved by using either a switch statement or by using a table with an enumeration value as an index. The number of tests required based on the source code could be considerably different depending upon the coverage required, although semantically we would want to test both approaches with a minimum number of tests. Decision coverage is stronger that statement coverage and it requires more test cases to achieve 100% decision coverage. Research in the industries have shown that even if through functional testing has been done it only achieves 40% to 60% decision coverage.
Function Call Coverage
Therefore coverage techniques are a great way to analyse and present the functioning of program in the light of specifications. Coverage technique offers a way to verify the various points at which a program may tend to behave abnormally or simply terminate. These coverage techniques also helps us to measure to what extent our program is successfully running and how is it handling errors, if any. In order to demonstrate that the conditions Y and Z can independently affect the decision outcome, the condition X must be false for those test cases.
A condition or predicate when evaluates to true must execute the next relevant line of code that follows. In this hypothetical example, that third critical test case would expose that latent bug. If you fail to provide that third case and use a coverage tool based solely on statement executions you will get a false sense that testing is complete.
Why use Code Coverage Testing?
Decision Coverage is a white box testing technique which reports the true or false outcomes of each boolean expression of the source code. The goal of decision coverage testing is to cover and validate all the accessible source code by checking and ensuring that each branch of every possible decision point is executed at least once. To widen the perspective of business testers, let us have a look at condition coverage as one of the so-called white box techniques. This technique focuses on having a more in-depth test of complex conditions that represent the underlying rules for a decision in a control flow graph. Within the business processes, the underlying rules of the decision points may evenly contain complex conditions. A combination of function coverage and branch coverage is sometimes also called decision coverage.
- Neither of these is necessarily the same as Full path coverage, when you traverse every path from the start node to every end node.
- Assume this function is a part of some bigger program and this program was run with some test suite.
- This method is not proficient amongst the software professionals, as it does not get approval from the management many times.
- This code needs three test cases, one more for the case where test1() evaluates to false but test2() evaluates to true.
- Eventually, between 2 nd and 3 rd, only C changed of value and decision’s outcome’s value also changed (passing from “true” to “false”).
Types of Code Coverage
The goal of Statement coverage is to cover all the possible path’s, line, and statement in the code. Thus in this example, the decision coverage will be reached with only 2 tests, and https://www.globalcloudteam.com/glossary/decision-condition-coverage/ the branch coverage on source code reach 100% with a single test. To achieve 100% decision coverage, your test cases must demonstrate a true and false outcome for each decision.
Fixed-point values in your model are integers during code coverage. However if the categorization leads to an unnecessary reduction of options for the tester, then we should cease using those categories. But overall if you see, all the statements are being covered by both scenarios. Decisions are recursive in that a decision can contain decisions as in the last example above. The decision X || C is one decision and X is actually another decision (A && B).A, B and C are conditions, because they contain no Boolean operators.
Example of Branch 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. It also creates some test cases to increase coverage and determining a quantitative measure of code coverage.
Hence the name ‘Decision Coverage’ testing was given to this process. In other words, the Decision Coverage testing is a requisite for certifying the modular code to have included the potential functional endpoints. Software authors can look at test coverage results to devise additional tests and input or configuration sets to increase the coverage over vital functions. Two common forms of test coverage are statement coverage and branch coverage. Line coverage reports on the execution footprint of testing in terms of which lines of code were executed to complete the test.
Result table of Decision Coverage:
This criterion requires that every point of entry and exit in the program has been invoked at least once, and every decision in the program has taken on all possible outcomes at least once. In this context, the decision is a boolean expression comprising conditions and zero or more boolean operators. This definition is not the same as branch coverage, however, the term decision coverage is sometimes used as a synonym for it. Decision coverage technique comes under white box testing which gives decision coverage to Boolean values.