Given-When-Then

Given-When-Then (GWT) is a semi-structured way to write down test cases. They can either be tested manually or automated as browser tests with tools like Selenium and Cucumber.^[1][2]

It derives its name from the three clauses used, which start with the words given, when and then.^[3] Given describes the preconditions and initial state before the start of a test and allows for any pre-test setup that may occur. When describes actions taken by a user during a test. Then describes the outcome resulting from actions taken in the when clause.

The Given-When-Then was proposed by Dan North in 2006, as part of behavior-driven development.^[4]

Example

A Given-When-Then test case for a hypothetical inventory software could be structured as follows:

GIVEN that the inventory contains 10 units of steel
    AND the inventory contains 30 units of copper
WHEN we consume 2 units of steel
    AND we consume 10 units of copper
    AND we purchase 5 units of steel
THEN the inventory should contain 13 units of steel
    AND the inventory should contain 20 units of copper
    AND the purchase of 5 units of steel should be registered in the expenses list

See also

• Acceptance test-driven development
• Acceptance testing
• Behavior-driven development
• Cucumber syntax
• Hoare triple