The Four-Phase Test is a testing pattern, applicable to all programming languages and unit tests (but not integration tests).
It takes the following general form:
test do setup exercise verify teardown end
There are four distinct phases of the test. They are executed sequentially.
During setup, the system under test (usually a class, object, or method) is set up:
user = User.new(password: "password")
During exercise, the system under test is exercised:
During verification, the result of the exercise is verified against the developer's expectations:
During teardown, the system under test is reset to its pre-setup state.
This is usually handled implicitly by the language (releasing memory) or test framework (running inside a database transaction).
The four phases are wrapped into a named test to be referenced individually.
A related style guideline advises we "Separate setup, exercise, verification, and teardown phases with newlines."
describe "#save" do it "encrypts the password" do user = User.new(password: "password") user.save expect(user.encrypted_password).to_not be_nil end end
Go forth and test in phases.