attachments.md

Attachments

Text, images and other data can be added to the output of the messages and JSON formatters with attachments. The world constructor is passed an attach function, which the default world constructor assigns to this.attach. If using a custom world constructor, you need to do this as well if you want to add attachments.

var {After} = require('@cucumber/cucumber');

After(function () {
  this.attach('Some text');
});

By default, text is saved with a MIME type of text/plain. You can also specify a different MIME type as part of a second argument:

var {After} = require('@cucumber/cucumber');

After(function () {
  this.attach('{"name": "some JSON"}', { mediaType: 'application/json' });
});

If you'd like, you can also specify a filename to be used if the attachment is made available to download as a file via a formatter:

var {After} = require('@cucumber/cucumber');

After(function () {
  this.attach('{"name": "some JSON"}', {
    mediaType: 'application/json',
    fileName: 'results.json'
  });
});

Images and other binary data can be attached using a stream.Readable. The data will be base64 encoded in the output. You should wait for the stream to be read before continuing by awaiting the returned promise or providing a callback.

var {After, Status} = require('@cucumber/cucumber');

// Awaiting the promise
After(async function (testCase) {
  if (testCase.result.status === Status.FAILED) {
    var stream = getScreenshotOfError();
    await this.attach(stream, { mediaType: 'image/png' });
  }
});

// Passing a callback
After(function (testCase, callback) {
  if (testCase.result.status === Status.FAILED) {
    var stream = getScreenshotOfError();
    this.attach(stream, { mediaType: 'image/png' }, callback);
  }
  else {
    callback();
  }
});

Images and binary data can also be attached using a Buffer. The data will be base64 encoded in the output.

var {After, Status} = require('@cucumber/cucumber');

After(function (testCase) {
  if (testCase.result.status === Status.FAILED) {
    var buffer = getScreenshotOfError();
    this.attach(buffer, { mediaType: 'image/png' });
  }
});

If you've already got a base64-encoded string, you can prefix your mime type with base64: to indicate this. Here's an example of saving a screenshot using Selenium WebDriver when a scenario fails:

var {After, Status} = require('@cucumber/cucumber');

After(async function (testCase) {
  if (testCase.result.status === Status.FAILED) {
    const screenshot = await driver.takeScreenshot()
    this.attach(screenshot, { mediaType: 'base64:image/png' })
  }
})

Attachments are also printed by the progress, progress-bar and summary formatters. They appear right after the step and only text/plain content is visible. It can be used to debug scenarios, especially in parallel mode.

// Step definition
Given('a basic step', async function() {
  this.attach('Some info.')
  this.attach('{"some": "JSON"}}', { mediaType: 'application/json' })
  this.attach((await driver.takeScreenshot()), {
    mediaType: 'base64:image/png',
    fileName: 'screenshot.png'
  })
})

// Result format
// ✔ Given a basic step # path:line
//    Attachment (text/plain): Some info.
//    Attachment (application/json)
//    Attachment (image/png): screenshot.png

Logging

You can log useful information from your support code with the simple log function:

var {After} = require('@cucumber/cucumber');

After(function () {
  this.log('Something interesting happened!');
});

Anything you log will be attached as a string with a MIME type of text/x.cucumber.log+plain

Links

You can attach one or more links from your support code with the link function:

var {Before, After} = require('@cucumber/cucumber');

Before(function () {
  this.link('https://cucumber.io');
});

After(function () {
  this.link(
    'https://github.com/cucumber/cucumber-js',
    'https://github.com/cucumber/cucumber-jvm',
    'https://github.com/cucumber/cucumber-ruby'
  );
});

Links will be attached as a string with a MIME type of text/uri-list