The Three Rules of TDD

1. You are not allowed to write any production code unless it is to make a failing unit test pass.
2. You are not allowed to write any more of a unit test than is sufficient to fail; and compilation failures are failures.
3. You are not allowed to write any more production code than is sufficient to pass the one failing unit test.

Which means the workflow is:

1. Write a failing test. Stop writing the test as soon as it fails.
2. Write the minimal production code required for the test to pass. Stop writing any code once the test passes.
3. Refactor the test code and the production code without altering the functionality. All tests should pass.

Usage

To run the tests, run npm run test.

Katas

Greeter

Before you start:

• Try not to read ahead.
• Do one task at a time. The trick is to learn to work incrementally.

This kata demonstrates the problems of static scoped functions and objects.

All tests should always pass, regardless of environment conditions.

1. Write a Greeter class with greet function that receives a name as input and outputs Hello <name>. The signature of greet should not change throughout the kata. You are allowed to construct Greeter object as you please.
2. greet capitalizes the first letter of the name
3. greet returns Good morning <name> when the time is 06:00-12:00
4. greet returns Good evening <name> when the time is 18:00-22:00
5. greet returns Good night <name> when the time is 22:00-06:00
6. greet logs into console each time it is called