Test coverage guide

1.The benefits of unit testing

• Unit test code can help everyone to go into details and understand the function of the code.
• We can find bugs by test case, and then enhance the robustness of the code.
• Test case code is also the demo usage of the core code.

2.Some design principle of unit test case

• Steps, fine-grained and combination conditions should be well designed.
• Attention to boundary condition test
• Test code should also be designed without writing useless code.
• When you find a method that is hard to write unit test, if you can be sure the method is "smelly code", then refactor it with the committer.
• The mock framework in dubbo is: jmockit.
• TDD（optional）：When you start a new issue, you can try to write test case at first

3.The specified value of the test coverage

• In the stage, the test coverage specified value of delta changed codes is ：>=60%
• We can see the coverage report in this page: https://codecov.io/gh/apache/incubator-dubbo