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After Screenshot API

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After a screenshot is taken, you can get details about the screenshot via the after:screenshot plugin event. This event is called when a screenshot is taken with cy.screenshot() or as a result of a test failure. The event is called after the screenshot image is written to disk.

This allows you to record those details, manipulate the image as needed, and return the updated details about the image.

Syntax

on('after:screenshot', (details) => { /* ... */ })

details (object)

An object describing the screenshot that was taken, with the following properties:

Property Type Description
size number The size of the image file (in bytes).
takenAt string The date and time the screenshot was taken. ISO 8601 format in UTC (example: '2020-03-09T07:30:37.686Z')
duration number Duration taking and saving the screenshot (in milliseconds).
dimensions object The width and height of the image in pixels (example: { width: 100, height: 50 })
multipart boolean Whether the screenshot was stitched together from multiple screenshot images.
pixelRatio number (Optional) The ratio of screenshot pixels to the browser’s displayed pixels.
name string (Optional) The fileName argument passed in via cy.screenshot()
specName string The name of the specfile where the screenshot was taken.
path string The absolute path to the image.
scaled boolean Whether the application under test was scaled to fit into the browser viewport. May be scale argument passed in via cy.screenshot()
blackout array The blackout argument passed in via cy.screenshot()

Usage

Modify screenshot details

Using your pluginsFile you can tap into the after:screenshot event.

If you change the path, size or dimensions of the image, you’ll want to update the new values so that the details are correctly reported in the test results. Any other properties besides path, size, and dimensions will be ignored.

You can return an object or a promise that resolves to an object from the callback function. Any type of returned value other than an object will be ignored. The object can contain the following properties:

  • path: The absolute path to the current location of the image
  • size: The size of the current image file (in bytes)
  • dimensions: The width and height of the current image in pixels (as an object with the shape { width: 100, height: 50 })

The properties will be merged into the screenshot details and passed to the onAfterScreenshot callback (if defined with Cypress.Screenshot.defaults() and/or cy.screenshot()).

Modify screenshot path

If you move the location of the screenshot image, you’ll want to specify the new path of the image.

// cypress/plugins/index.js
const fs = require('fs')

module.exports = (on, config) => {
  on('after:screenshot', (details) => {
    console.log(details) // print all details to terminal

    const newPath = '/new/path/to/screenshot.png'

    return new Promise((resolve, reject) => {
      // fs.rename moves the file to the existing directory 'new/path/to'
      // and renames the image to 'screenshot.png'
      fs.rename(details.path, newPath, (err) => {
        if (err) return reject(err)

        // because we renamed and moved the image, resolve with the new path
        // so it is accurate in the test results
        resolve({ path: newPath })
      })
    })
  })
}

See also