Running Tests

Cucumber

Cucumber is the primary way to run your test suite. It picks up all .feature files, reads configuration from cucumber.js, and reports results across all scenarios.

npx cucumber-js

The output identifies the failing step, the URL, and the specific locator that failed:

Scenario: Visitor sees the homepage greeting # features/homepage.feature:3
   Last passed: commit d498a33, 1 commit ago
   ✔ Before
   ✔ Given I'm on the homepage
   ✖ Then the page contains text "Hello world"
       URL: /
       Locator: text=/Hello world/i
       Error: element(s) not found
   - And I should be on page "/"
   ✔ After

Plugin

The letsrunit cucumber plugin stores test results with HTML and screenshots for every step, allowing it to create a diff to identify the issue. It also tracks the git commit hash for each test run to show what has changed since the last time a scenario passed.

Failure explanations

letsrunit explain analyzes failures from the latest stored run and prints a human-readable explanation of whether the test likely needs an update or the product likely regressed.

features/homepage.feature :: Visitor sees the homepage greeting
  ✔ Given I'm on the homepage
  ✖ Then the page contains text "Hello world"
  - Then I should be on page "/"

  Possible regression
  The page heading text was changed from "Hello world" to "Hllo world", so the expected greeting is missing.
  💡 Fix the homepage text to read exactly "Hello world".

If the latest run has no failures, it exits successfully with nothing to explain.

Running specific files or tags

Run a single feature file:

npx cucumber-js features/login.feature

Run scenarios with a specific tag:

npx cucumber-js --tags @smoke

Tag scenarios in your feature files:

@smoke
Scenario: User logs in
  Given I'm on page "/login"
  ...