Before Run API

The before:run event fires before a run starts. When running cypress via cypress open, the event will fire when opening a project.

The event will fire each time cypress run executes. As a result, if running your specs in parallel, the event will fire once for each machine on which the tests are run.

Syntax

const { defineConfig } = require('cypress')

module.exports = defineConfig({
  // setupNodeEvents can be defined in either
  // the e2e or component configuration
  e2e: {
    setupNodeEvents(on, config) {
      on('before:run', (details) => {
        /* ... */
      })
    }
  }
})

import { defineConfig } from 'cypress'

export default defineConfig({
  // setupNodeEvents can be defined in either
  // the e2e or component configuration
  e2e: {
    setupNodeEvents(on, config) {
      on('before:run', (details) => {
        /* ... */
      })
    }
  }
})

// cypress/plugins/index.js

module.exports = (on, config) => {
  on('before:run', (details) => {
    /* ... */
  })
}

details (Object)

Details of the run, including the project config, system information, and the version of Cypress. More details are included when running via cypress run.

Usage

You can return a promise from the before:run event handler and it will be awaited before Cypress proceeds running your specs.

Log the browser and the number of specs that will be run

module.exports = (on, config) => {
  on('before:run', (details) => {
    // details will look something like this when run via `cypress run`:
    // {
    //   config: {
    //     projectId: '12345',
    //     baseUrl: 'http://example.com/',
    //     viewportWidth: 1000,
    //     viewportHeight: 660,
    //     // ...more properties...
    //   },
    //   browser: {
    //     name: 'electron',
    //     version: '59.0.3071.115',
    //     // ...more properties...
    //   },
    //   system: {
    //     osName: 'darwin',
    //     osVersion: '16.7.0',
    //   }
    //   cypressVersion: '6.1.0',
    //   specs: [
    //     {
    //       name: 'login_cy.js',
    //       relative: 'cypress/e2e/login_cy.js',
    //       absolute: '/Users/janelane/app/cypress/e2e/login_cy.js',
    //     },
    //     // ... more specs
    //   ],
    //   specPattern: [
    //     '**/*.cy.{js,jsx,ts,tsx}'
    //   ],
    //   parallel: false,
    //   group: 'group-1',
    //   tag: 'tag-1'
    // }

    // details will look something like this when run via `cypress open`:
    // {
    //   config: {
    //     projectId: '12345',
    //     baseUrl: 'http://example.com/',
    //     viewportWidth: 1000,
    //     viewportHeight: 660,
    //     // ...more properties...
    //   },
    //   system: {
    //     osName: 'darwin',
    //     osVersion: '16.7.0',
    //   }
    //   cypressVersion: '7.0.0'
    // }

    if (details.specs && details.browser) {
      // details.specs and details.browser will be undefined in interactive mode
      console.log(
        'Running',
        details.specs.length,
        'specs in',
        details.browser.name
      )
    }
  })
}

See also