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, executed sequentially.
Set up system under test (usually a class, object, or method):
user = User.new(password: "password")
Exercise the system under test:
Verify the result of the exercise against the developer's expectations:
Tear down the system under test 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.
A related style guideline is to 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