The analysis method that shows which parts of the code have been tested or not is called Code Coverage. Statement Coverage, Decision Coverage and Condition Coverage can be given as examples in this concept. The Code Coverage method is used to determine the rate at which prepared tests, such as unit tests, are tested in your project code. One of the important signs of quality code is that it has been tested. Line by line, how much of a function has been tested is a factor that directly affects its reputation. Code Coverage simply shows how much of the code written has been tested. Code Coverage is one of the types of White Box Testing.
Importance of Code Coverage Analysis
One of the important signs of quality code is that it has been tested. Line by line, how much of a function has been tested is a factor that directly affects its reputation.
It is necessary to run tests to ensure effective protection against errors. This is an important point to avoid code coverage errors in as large a part of the scope as possible. It means the analysis of all solution methods prepared through unit tests.
The higher the Code Coverage ratio, the higher the quality of the software.
How to Analyze the Code with Code Coverage?
There are many tools for code coverage testing in many different programming languages. Here is a list of tools that perform code coverage testing for different programming languages and platforms.
Code Coverage Tools
- Cobertura – Java
- JaCoCo – Java
- Coverage.py – Python
- NCover – .Net
- dotCover – .Net
- OpenCover – .Net
- CoverageMeter – C / C++
By testing the code coverage with the tools above, you can find out how much of the tests prepared covers the code.
You can reach the goal of 100% code coverage by writing more tests to cover which code is not covered. After updating the code, you should definitely run the code coverage test.
When the application is developed by adhering to the principles of Test Driven Development (TDD), it means that we are progressing by testing every function of the code. This will naturally result in a high Code Coverage value.
How to Manage the Code Coverage Results?
In addition to the tests that will be run with every change made in the code, the code coverage test should also be run. The results of the code coverage tests should be stored in a directory for later comparison with other results or for analyzing. Code coverage results are usually stored in files in XML or JSON format. Some tools can send this data by e-mail in the form of a report.
What are the Code Coverage Methods?
Here is a list of common Code Coverage Methods:
- Statement Coverage
- Decision Coverage
- Condition Coverage
- Branch Coverage
- Toggle Coverage
- Function Coverage
- FSM Coverage
- Path Coverage
The Formula of Code Coverage
There is a basic formula that measures the code coverage.
Benefits of Code Coverage
- It measures how much part of the code is tested.
- Improves code quality.
- Increases the reliability of the software
- Makes code maintenance easier.
- It exposes bad code.