Talk for ngVikings 2019 in which we discuss the basics of TDD: what it is, how to do it, and why

1. Write Better
Tests With TDD
Alex Hoffman

2. @alexhoffman617
• Test Driven Development
• Writing tests to drive development in small feedback cycles

3. @alexhoffman617
• TDD rules as defined by Rob Martin (author of the Agile
Manifesto)
• You are not allowed to write any production code unless it
is to make a failing unit test pass.
• You are not allowed to write any more of a unit test than is
sufficient to fail
• You are not allowed to write any more production code
than is sufficient to pass the one failing unit test.

4. @alexhoffman617
Write
Failing Test
Passing
Test
Code

5. @alexhoffman617
• twitter: @alexhoffman617
• github: alexhoffman617

6. @alexhoffman617
Code:Tests:

7. @alexhoffman617
Code:Tests: Requirements:
• Take a number input
• Output true if its Tuesday
• Output false if its not Tuesday

8. @alexhoffman617
• Code follows requirements
• Helps developers think about code on a more granular level
• Makes code more readable
• Prevents unnecessary code or complications

9. @alexhoffman617
Tests:Requirements:

10. @alexhoffman617
• Lets Be Practical
• Do it when you have branching logic
• Complex situations
• Low effort, high impact

11. @alexhoffman617
tb; fa

12. @alexhoffman617
• Test Driven Development is using Red-Green refactor
• By writing tests before coding, you’ll test your requirements
• Will improve how you think about coding and testing,
readability, and your chance of catching edge cases
• Promotes world peace

13. Thanks!
alexhoffman617
@alexhoffman617