cypress-on-fix

Fixes multiple Cypress plugins subscribing to "on" events

See #22428 issue.

Read the blog post Fix For Cypress Plugin Events.

Install

Add this NPM package as a dev dependency

# install using NPM
$ npm i -D cypress-on-fix
# install using Yarn
$ yarn add -D cypress-on-fix

Wrap the on passed by Cypress in your config file

const { defineConfig } = require('cypress')

module.exports = defineConfig({
  e2e: {
    // baseUrl, etc
    supportFile: false,
    fixturesFolder: false,
    setupNodeEvents(cypressOn, config) {
      // https://github.com/bahmutov/cypress-on-fix
      const on = require('cypress-on-fix')(cypressOn)
      // use "on" to register plugins, for example
      // https://github.com/bahmutov/cypress-split
      require('cypress-split')(on, config)
      // https://github.com/bahmutov/cypress-watch-and-reload
      require('cypress-watch-and-reload/plugins')(on, config)
      // https://github.com/bahmutov/cypress-code-coverage
      require('@bahmutov/cypress-code-coverage/plugin')(on, config)
    },
  },
})

If there are multiple plugins that returns a value, the last one result will be returned

const on = require('cypress-on-fix')(cypressOn)
on('before:browser:launch', (browser, launchOptions) => {
  if (browser.name === 'chrome') {
    launchOptions.args.push('--window-size=1366,768')
    return launchOptions
  }
})
on('before:browser:launch', (browser, launchOptions) => {
  if (browser.name === 'chrome') {
    launchOptions.args.push('--window-size=1280,720')
    return launchOptions
  }
})

In the situation above, the Chrome browser will be opened with the window size 1280x720

Debugging

This module uses debug to print verbose log messages. Run Cypress with

DEBUG=cypress-on-fix npx cypress run ...

Example

setupNodeEvents(on, config) {
  on('after:spec', (a) => {
    console.log('after spec 1', a.relative)
  })
  on('after:spec', (a) => {
    console.log('after spec 2', a.relative)
  })
  on('after:spec', (a) => {
    console.log('after spec 3', a.relative)
  })
}

Without this plugin only the last event listener is invoked

after spec 3 cypress/e2e/spec1.cy.js

With this proxy, all listeners are invoked

setupNodeEvents(cypressOn, config) {
  // https://github.com/bahmutov/cypress-on-fix
  const on = require('cypress-on-fix')(cypressOn)
  on('after:spec', (a) => {
    console.log('after spec 1', a.relative)
  })
  on('after:spec', (a) => {
    console.log('after spec 2', a.relative)
  })
  on('after:spec', (a) => {
    console.log('after spec 3', a.relative)
  })
}

after spec 1 cypress/e2e/spec1.cy.js
after spec 2 cypress/e2e/spec1.cy.js
after spec 3 cypress/e2e/spec1.cy.js

Small print

Author: Gleb Bahmutov <[e-mail]> © 20223

• @bahmutov
• glebbahmutov.com
• blog
• videos
• presentations
• cypress.tips
• Cypress Tips & Tricks Newsletter
• my Cypress courses

License: MIT - do anything with the code, but don't blame me if it does not work.

Support: if you find any problems with this module, email / tweet / open issue on Github

MIT License

Copyright (c) 2023 Gleb Bahmutov <[e-mail]>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.