Intro to RSpec
TDD and BDD
REQUIREMENT
REQUIREMENT
REQUIREMENT
REQUIREMENT
REQUIREMENT
TEST
REQUIREMENT
REQUIREMENT
CODE
Why ?
Is it to attract Ruby job ??
Your first friend to fight Errors
Your guide when refactoring your messed up code
Acts as testable documentation
What is RSpec
DSL for testing Ruby code
Why RSpec?
Widely popular
It doesn't matter which framework you used as long as you write a test
Approach
GREEN
REFACTOR
RED
How To
- Choose class / method / behavior to test
- Write test
- Write code to make the test pass
- Refactor code and make sure the test is still passed
Skip this chit-chat
Show me the code!
Assume we have a requirement
As a husband I need to have at least Rp 10.000 in my wallet's balance.
My wife asked me to buy a mango using my balance.
RED
RSpec.describe Wallet do
subject { Wallet.new(1) }
it "should have default balance" do
expect(subject.balance).to eq(10000)
end
endRSpec.describe BuyFruit do
let(:wallet) { Wallet.new(1) }
it "should have brought fruit" do
shopping = BuyFruit.call(wallet, 9000)
expect(shopping[:status]).to eq(true)
expect(shopping[:wallet].balance).to eq(1000)
end
it "should have not brought fruit" do
shopping = BuyFruit.call(wallet, 12000)
expect(shopping[:status]).to be_falsey
expect(shopping[:wallet].balance).to eq(10000)
end
end
GREEN
class Wallet
attr_reader :id, :balance
def initialize(id, balance = 10000)
@id = id
@balance = balance
end
def balance=(n)
@balance = n
end
end
class BuyFruit
def self.call(wallet, price)
options = {}
options[:wallet] = wallet
options[:status] = false
if options[:wallet].balance >= price
options[:wallet].balance -= price
options[:status] = true
end
options
end
end
REFACTOR
class DecreaseBalance
def self.call(wallet, amount)
options = {}
options[:wallet] = wallet
options[:status] = false
if options[:wallet].balance >= amount
options[:wallet].balance -= amount
options[:status] = true
end
options
end
end
class BuyFruit
def self.call(wallet, price)
options = {}
transaction = DecreaseBalance.(wallet, price)
options[:status] = transaction[:status]
options[:wallet] = transaction[:wallet]
options
end
endMy experiences
- Don't believe everything what I said
- Red-Green-Refactor is just a myth for me
- What I did was Code-Red-Green-Refactor
- It's okay as long as you write your test
- But it's better if you write the test first
- Cover mostly on the business processes