The Cucumber Book, 2nd Edition

Steps and Step Definitions

Let’s start by clarifying the distinction between a step and a step definition.

Each Gherkin scenario is made up of a series of steps, written in plain language. On its own, a step is just documentation; it needs a step definition to bring it to life. A step definition is a piece of Ruby code that says to Cucumber, “If you see a step that looks like this…, then here’s what I want you to do….”

When Cucumber tries to execute each step, it looks for a matching step definition to execute. So, how does Cucumber match a step definition to a step?

Matching a Step

Gherkin steps are expressed in plain text. Cucumber scans the text of each step for patterns that it recognizes, which you define using a regular expression ...