RSpec ist ein Behavior-Driven Development (BDD) Test-Framework für Ruby.
Grundlegende Spec-Struktur
RSpec.describe Calculator do
let(:calculator) { Calculator.new }
describe "#add" do
context "when adding positive numbers" do
it "returns the arithmetic sum" do
expect(calculator.add(2, 3)).to eq(5)
end
end
context "when given invalid input" do
it "raises an ArgumentError" do
expect { calculator.add(2, "x") }.to raise_error(ArgumentError)
end
end
end
end
Wichtige Matcher
# Gleichheit
expect(actual).to eq(expected) # Wertgleichheit (==)
expect(actual).to be(expected) # Objektidentität (equal?)
# Wahrheitswerte & Prädikate
expect(actual).to be_truthy
expect(actual).to be_nil
expect(user).to be_active # Ruft user.active? auf
# Kollektionen
expect(list).to include("ruby")
expect(list).to match_array([1, 2]) # Gleiche Elemente unabhängig von der Reihenfolge
expect(list).to be_empty
# Vergleiche
expect(value).to be > 10
expect(value).to be_between(1, 100).inclusive
# Fehler & Exceptions
expect { risky_call }.to raise_error(StandardError, /message/)
expect { safe_call }.not_to raise_error
Mocks & Stubs (rspec-mocks)
# Methoden-Stubbing
allow(user).to receive(:name).and_return("Alice")
# Erwartung bei Methodenaufruf
expect(notifier).to receive(:send_email).with("[email protected]").once
# Double (Mock-Objekt)
mock_service = double("PaymentService", charge: true)