Relevance of Test Coverage in Software Testing
Test Coverage is an important indicator of software quality and an essential part of software maintenance. It helps in evaluating the effectiveness of testing by providing data on different coverage items. It is a useful tool for finding untested parts of a code base. Test coverage is also called code coverage in certain cases.
Test coverage can help in monitoring the quality of testing and assist in directing the test generators to create test cases that cover areas that have not been tested. It helps in determining a quantitative measure of Test coverage, which is an indirect measure of quality and identifies redundant test cases that do not increase coverage.
The output of coverage measurement can be used in several ways to improve the testing process:
- Traceability between the requirements and test cases can be established by measuring the Test Coverage
- Change tracking, Impact analysis will be effective if we have proper Test mechanism in place
- Defect leakage will be prevented with proper Test Coverage
- Gaps in requirements, test cases and defects at unit level can be found in an easy way
Benefits of Test Coverage
- Defect prevention at early stages of project life cycle
- It creates additional test cases to increase coverage
- Better ROI will be achieved by reduction in UAT defects and production defects
- It helps in finding areas of a program not exercised by a set of test cases
- Time, Cost and Scope will be in control
- Testing life will become smooth by managing the Risk based testing approach
- It helps in determining a quantitative measure of code coverage, which indirectly measures the quality of the application or product.
Test coverage tools
The Test Coverage tools are used to locate application functionality. One simply exercises the functionality of interest, and the test coverage tool indicates what part of the application code is executed. This is a very effective way to locate functionality in a large, poorly understood system. Coverage tools helps in checking that how thoroughly the testing has been done.
Features or characteristics of coverage measurement tools are as follows:
- To identify coverage items (instrumenting the code)
- To calculate the percentage of coverage items that were tested by a set of tests
- To report coverage items that have not been tested yet
- To generate stubs and drivers (if part of a unit test framework)
It is very important to know that the coverage tools only measure the coverage of the items that they can identify. Just because your tests have achieved 100% statement coverage, this does not mean that your software is 100% tested!
We may ask what is the value of coverage analysis? The above blog has summarised that testing coverage helps you find which bits of your code aren’t being tested. It’s worth running coverage tools often and looking at these bits of untested code.