CF SESSIONS
Test Driven Development
Writing Better Code in Less Time
theCloudFactoryHQ
Smart People
Smart Programmers
High Progress
Without Any Process
NOT A GOOD THING
We know how houses are built.
Just give us some bricks and we'll get started.
PROFESSIONals
★ PROCESS ★
DESIGN, PLAN AND PREPARE FIRST
TDD is a design process, not a testing process
TDD And Us
If I write tests, I may not finish this feature on time.
Don't be this guy
I'll go back and write tests afterwards
Don't be this guy
TEST FIRst !!!
Don't be this guy either
TESTS PROVIDES
- Documentation of code
- Catch future errors
- Long-term time savings
Tests are Tools
Test Driven Development
- Understand the requirement
- Decide what the code will do
- Write a test that will pass if the code does that thing
- Run the test, see it fail
- Write the code
- Run the test, see it pass
TDD PROVIDES
- Design and plan before we code
- Document our design
- Proof that code implements design
Encourage design of Testable code
TESTABLE CODE IS A GOOD CODE
Modular
Decouple Design
Methods of Limited Scope
Reduction in Cyclomatic Complexity
EASY TO FIND BUGS
EASY TO UNDERSTAND
EASY TO MAINTAIN
EASY TO DEVELOP
TEST DRIVEN DESIGn
FASTER AND BETTER
But ..
It does take a while to learn this
HOW DO I TDD
Units, Integration, Functional
Integration tests are Scam
Yes, You Should Write Controller Tests!
Don’t use Cucumber unless you live in the magic kingdom of non-programmers-writing-tests
Don’t aim for 100% coverage
Don’t test standard Active Record associations, validations, or scopes.
You’re probably doing it wrong if testing is taking more than 1/3 of your time.
A test is not a unit test if it talks to the database, or touches the file system
Do not test APIs with Capybara. It wasn’t designed for it.
Make TDD to
-
build your road map
-
guide you
-
optimize
Unit: Do our objects do the right thing, and are they convenient to work with?
Integration: Does our code work against code we can’t change?
Acceptance: Does the whole system work?
Skinny Controller
Fat Models
Fatter Lib Files
No Test Should Repeat
Test may be skipped for exploratory code
TDD In CF
USE-CASE 1:
Interface
Change
Event
Respond
USE-CASE 2:
APIS - REQUEST - RESPONSE
Params to accept ( What we receive)-
Params to send (What we have to return)
- Status Codes
FEEDBACK
And