Test¶

Test-driven Development (TDD)¶

Tests are written before code and 'passing' the test is the critical driver of development
You develop code incrementally, along with a test for that increment. You dont move on to the next increment before code has passed its test
TDD was introduced as part of agile methods such as XP. However, it can also be used in plan-driven development processes.

Start by identifying the increment of functionality that is required. This should normally be small and implementable in a few lines of code
Write a test for this functionality and implement this as an automated test
Run the test, along with all other tests that have been implemented. Initially, you have not implemented the functionality so the new test will fail
Implement the functionality and re-run the test
Once all tests run successfully, you move on to implementing the next chunk of functionality

Code Coverage
- Every code segment that you write has at least one associated test so all code written has at least one test
Regression Testing
- A regression test suite is developed incrementally as a program is developed.
Simplified Debugging
- When a test fails, it should be obvious where the problem lies. The newly written code needs to be checked and modified
System Documentation
- The tests themselves are a form of documentation that describe what the code should be doing.

Last update: January 22, 2020