Bdd Scenarios

BDD scenarios

Behavior-driven development (BDD) scenarios earn their keep only when a product owner reads one and agrees it describes the intended behavior. Padded with UI clicks or written in code-speak, they become slow tests that nobody outside engineering trusts. The whole discipline is keeping each scenario in the language of the business, not the implementation.

Method

1. One scenario, one rule. A scenario names a single behavior: Applying an expired coupon leaves the price unchanged. If the title needs "and" to be honest, split it. Twelve tight scenarios read better than three that each test four things.
2. Given sets state, When is one action, Then is the observable result. Given is prior facts (Given a cart totaling $80), When is the single trigger under test (When the customer applies coupon SAVE10), Then is what a user or the system can see (Then the total is $72). Never put an action in Given or a second When before the Then.
3. Speak the domain, not the DOM. Write When the customer submits the order, not When I click #submit-btn. Selectors and keystrokes belong in the step definitions, hidden from the reader. A scenario tied to markup breaks on a redesign that changed no behavior.
4. Push the value matrix into Scenario Outline. One outline with an Examples table covers SAVE10, SAVE20, and an expired code in three rows instead of three near-identical scenarios. Keep each row a distinct rule, not just a distinct number.
5. Keep Background to shared facts only. Background runs before every scenario in the file, so it holds setup common to all of them and nothing scenario-specific. If a Given appears in every scenario, promote it; if it appears in two, leave it inline.
6. Bind steps to intent in the step layer. With Cucumber, Behave, pytest-bdd, or SpecFlow, one step phrase maps to one function. Reuse phrases so the vocabulary stays small and the glue code stays shared.

Litmus tests

• Can a non-engineer read the .feature file aloud and say whether it matches the intended rule?
• Does every Then assert something a user or downstream system observes, never an internal call or private field?
• If the UI were rebuilt with new markup, would the scenarios survive untouched while only step definitions changed?

Boundaries

BDD is for behavior stakeholders care about, not for exhaustive edge cases: push the empty, boundary, and malformed-input matrix down to unit tests where it stays fast and cheap. Follow the team's existing feature-file layout and tag scheme over the structure shown here.