Todo list TDD tutorial

• Doing the todo list tutorial again, but this time tests are written first.
• The implementation will be skipped over, because it's already shown in the original tutorial.

Getting started with TDD

• Good rule: do not write any code until there's a failing test ready for it.
• Then, write the smallest amount of code possible to satisfy the test.
• Then repeat - trying to cover all edge cases.
• When complete, the software will be bulletproof, new features will be easy to add without regressing functionality.

First steps

• No need to test that a TodoItem class can be constructed, or that its properties are the correct value - that's pointless.
• First test: the todo list should be empty by default - easy to test.
• Next: requesting a todo item by ID should be null.
• Next: after creating a todo item, it should be in the todo list.
• Next: after creating a todo item, it should be retrievable. Then it should be editable, and the next retrieved todo item should have the changed content.
• Next: toggle complete status.
• Next: delete items.
• Next: entire functionality complete, but this time functionality is provable.

Behavioural tests

• Introduce Behat browser testing.

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Move on to the next tutorial: [[address book tutorial]].