cucumber-basics.md

Expressions

A step definition’s expression can either be a regular expression or a cucumber expression. The examples in this section use cucumber expressions. If you prefer to use regular expressions, each capture group from the match will be passed as arguments to the step definition’s function.

Given(/I have {int} cukes in my belly/, (cukes: number) => {});

Arguments

Steps can be accompanied by doc strings or data tables, both which will be passed to the step definition as the last argument, as shown below.

Feature: a feature
  Scenario: a scenario
    Given a table step
      | Cucumber     | Cucumis sativus |
      | Burr Gherkin | Cucumis anguria |

import { Given, DataTable } from "@klaveness/cypress-cucumber-preprocessor";

Given(/^a table step$/, (table: DataTable) => {
  const expected = [
    ["Cucumber", "Cucumis sativus"],
    ["Burr Gherkin", "Cucumis anguria"]
  ];
  assert.deepEqual(table.raw(), expected);
});

See here for DataTable's interface.

Custom parameter types

Custom parameter types can be registered using defineParameterType(). They share the same scope as tests and you can invoke defineParameterType() anywhere you define steps, though the order of definition is unimportant. The table below explains the various arguments you can pass when defining a parameter type.

Argument	Description
name	The name the parameter type will be recognised by in output parameters.
regexp	A regexp that will match the parameter. May include capture groups.
transformer	A function or method that transforms the match from the regexp. Must have arity 1 if the regexp doesn't have any capture groups. Otherwise the arity must match the number of capture groups in regexp.

Pending steps

You can return "pending" from a step defintion or a chain to mark a step as pending. This will halt the execution and Cypress will report the test as "skipped".

import { When } from "@klaveness/cypress-cucumber-preprocessor";

When("a step", () => {
  return "pending";
});

import { When } from "@klaveness/cypress-cucumber-preprocessor";

When("a step", () => {
  cy.then(() => {
    return "pending";
  });
});

Nested steps

You can invoke other steps from a step using Step(), as shown below.

import { When, Step } from "@klaveness/cypress-cucumber-preprocessor";

When("I fill in the entire form", function () {
  Step(this, 'I fill in "john.doe" for "Username"');
  Step(this, 'I fill in "password" for "Password"');
});

Step() optionally accepts a DataTable or string argument.

import {
  When,
  Step,
  DataTable
} from "@klaveness/cypress-cucumber-preprocessor";

When("I fill in the entire form", function () {
  Step(
    this,
    "I fill in the value",
    new DataTable([
      ["Field", "Value"],
      ["Username", "john.doe"],
      ["Password", "password"]
    ])
  );
});

Hooks

Before() and After() is similar to Cypress' beforeEach() and afterEach(), but they can be selected to conditionally run based on the tags of each scenario, as shown below. Furthermore, failure in these hooks does not result in remaining tests being skipped. This is contrary to Cypress' beforeEach and afterEach.

import { Before } from "@klaveness/cypress-cucumber-preprocessor";

Before(function () {
  // This hook will be executed before all scenarios.
});

Before({ tags: "@foo" }, function () {
  // This hook will be executed before scenarios tagged with @foo.
});

Before({ tags: "@foo and @bar" }, function () {
  // This hook will be executed before scenarios tagged with @foo and @bar.
});

Before({ tags: "@foo or @bar" }, function () {
  // This hook will be executed before scenarios tagged with @foo or @bar.
});