The development team decided to use TDD for several reasons. First, the team wanted a way to clearly measure progress during the development process. Second, they wanted to be able to reuse the tests in subsequent development cycles in order to continue to validate existing functionality while new functionality is added. For these reasons, the team will use unit tests to verify that the functionality written satisfies the given requirements of the team.

The following diagram illustrates the basics of TDD:

Tests are added and the code base is updated until all the defined tests pass. It is important to note that this is repeated. In each iteration, new tests are added and the tests are not considered passed until all tests, new and existing, pass.

The FlixOne development team decided to incorporate both unit tests and UAT into a single agile cycle. At the beginning of each cycle, new acceptance criteria would be determined. This would include the functionality to be delivered, as well as how it would be verified or accepted at the end of the development cycle. These acceptance criteria would then be used to add tests to the project. The development team would then build the solution until the new and existing tests passed, and then prepare a build for acceptance testing. Then, the acceptance testing would be run, and if any issues were detected, the development team would define new tests or amend existing tests based on the failures. The application would be developed again until all tests passed and a new build would be prepared. This would be repeated until acceptance testing passed. Then, the application would be deployed and a new development cycle would begin.

The following diagram illustrates this approach:

The team now has a plan, so let's start coding!