Using CucumberJS with Nightwatch Suggest edits

Overview

Nightwatch 2 brings integrated support for using Cucumber.js directly as an alternative test runner. No other plugins are necessary, other than the Cucumber library itself (version 7.3 or higher).

Simply run the following in the same project where Nightwatch is also installed:

npm i @cucumber/cucumber --save-dev

Configuration

In order to use CucumberJS in Nightwatch you need to set the test_runner config property and set the type to cucumber. You will also need to set the path to where the feature files are located.

nightwatch.conf.js
{
  test_runner: {
    // set cucumber as the runner
    type: 'cucumber',

    // define cucumber specific options

    options: {
      //set the feature path
      feature_path: 'examples/cucumber-js//.feature',

      // start the webdriver session automatically (enabled by default)
      auto_start_session: true,

      // use parallel execution in Cucumber
      // set number of workers to use (can also be defined in the cli as --parallel 2
      parallel: 2 
    }
  },

  src_folders: ['examples/cucumber-js/features/step_definitions']
}

Running Tests

The easiest way to run Cucumber tests from examples is:

npx nightwatch --env cucumber-js

Cucumber spec files/step definition files can be provided in src_folders in Nightwatch config or as a CLI argument.

With src_folders defined:
npx nightwatch
Without src_folders defined:
npx nightwatch examples/cucumber-js/features/step_definition

Running in Parallel

Parallel running using 2 workers:

nightwatch examples/cucumber-js/features/step_definitions --parallel 2

Use other test runner options as usual:

npx nightwatch examples/cucumber-js/features/step_definitions --headless

Manually Starting the WebDriver Session

You might need sometimes to not start the Webdriver session automatically after Nightwatch is instantiated. For this purpose, Nightwatch provides the instance available as this.client, which contains an launchBrowser() method.

Configuration

nightwatch.conf.js
{
  test_runner: {
    type: 'cucumber',
    options: {
      feature_path: 'examples/cucumber-js//.feature',
      auto_start_session: false
    }
  }
}

You can then use an extra setup file that you can pass as an extra --require to Nightwatch, which will be forwarded to Cucumber. In the extra setup file, you can add other operations needed to be executed before the session is started.

Example _extra_setup.js:

Remember to set the browser on this so it can be closed automatically by Nightwatch. Otherwise, remember to call .quit() in your own Cucumber After() hooks.

_extra_setup.js 
const {Before} = require('@cucumber/cucumber');

Before(async function(testCase) {
  if (!this.client) {
    console.error('Nightwatch instance was not created.');

    return;
  }

  this.client.updateCapabilities({
    testCap: 'testing'
  });

  this.browser = await this.client.launchBrowser();
});

Run with extra setup

nightwatch examples/cucumber-js/features/step_definitions --require {/full/path/to/_extra_setup.js}

Nightwatch setup file for Cucumber

You might also want to inspect the built-in setup file that Nightwatch uses for initializing the Cucumber runner. It is available in our project root folder at /cucumber-js/_setup_cucumber_runner.js.

Reporting

When using the integrated Cucumber test runner, you need to use the Cucumber formatters for generating output.

Nightwatch reporters (like JUnit XML reports or the global custom reporter) are not available. The main reason is that reporting is delegated to the Cucumber CLI. You can also write your own Cucumber formatter.

Nightwatch will forward --format and --format-options CLI arguments, if present, to Cucumber.

By default, the progress formatter is used.

For example:

npx nightwatch --env cucumber-js --format @cucumber/pretty-formatter

or:

npx nightwatch --env cucumber-js --require cucumber.conf.js --format json:report/cucumber_report.json

Example Output

Here's how the output looks like when running the example tests in Firefox. You can just run this in the project where Nightwatch is installed:

npx nightwatch examples/cucumber-js/features/step_definition
ℹ Connected to GeckoDriver on port 4444 (1740ms).
Using: firefox (92.0.1) on MAC (20.6.0).

..  ✔ Testing if the page title equals 'Rijksmuseum Amsterdam, home of the Dutch masters' (4ms)
.  ✔ Element <#rijksmuseum-app> was visible after 46 milliseconds.
.  ✔ Testing if element <.search-results> contains text 'Operation Night Watch' (1994ms)
...  ✔ Testing if the page title equals 'Rijksmuseum Amsterdam, home of the Dutch masters' (8ms)
.  ✔ Element <#rijksmuseum-app> was visible after 49 milliseconds.
.  ✔ Testing if element <.search-results> contains text 'The Night Watch, Rembrandt van Rijn, 1642' (1427ms)
.

2 scenarios (2 passed)
10 steps (10 passed)
0m13.024s (executing steps: 0m12.998s)
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