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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​

caution

⚠️ This code is part of the setupNodeEvents function and thus executes in the Node environment. You cannot call Cypress or cy commands in this function, but you do have the direct access to the file system and the rest of the operating system.

caution

⚠️ When running via cypress open, the before:run event only fires if the experimentalInteractiveRunEvents flag is enabled.

:::cypress-plugin-example

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​