{ "doc": { "id": "api/node-events/before-run-api", "title": "Before Run Event | Cypress Node Events", "description": "The before:run event fires before a run starts in Cypress.", "section": "api", "source_path": "/llm/markdown/api/node-events/before-run-api.md", "version": "e6988a974973e9090ce70406c38cb2b9e0eac9fa", "updated_at": "2026-05-15T15:50:22.536Z", "headings": [ { "id": "api/node-events/before-run-api#before-run-event", "text": "Before Run Event", "level": 1 }, { "id": "api/node-events/before-run-api#syntax", "text": "Syntax", "level": 2 }, { "id": "api/node-events/before-run-api#usage", "text": "Usage", "level": 2 }, { "id": "api/node-events/before-run-api#log-the-browser-and-the-number-of-specs-that-will-be-run", "text": "Log the browser and the number of specs that will be run", "level": 3 }, { "id": "api/node-events/before-run-api#see-also", "text": "See also", "level": 2 } ] }, "chunks": [ { "id": "api/node-events/before-run-api#syntax", "doc_id": "api/node-events/before-run-api", "heading": "Syntax", "heading_level": 2, "content_markdown": "## Syntax\n\n⚠️ This code is part of the [setupNodeEvents](/llm/markdown/app/plugins/plugins-guide.md#Using-a-plugin) 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.\n\n⚠️ When running via `cypress open`, the `before:run` event only fires if the [experimentalInteractiveRunEvents flag](/llm/markdown/app/references/experiments.md#Configuration) is enabled.\n\n* cypress.config.js\n* cypress.config.ts\n\n```\nconst { 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) => { /* ... */ }) }, },})\n```\n\n```\nimport { 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) => { /* ... */ }) }, },})\n```\n\n**details _(Object)_**\n\nDetails of the run, including the project config, system information, and the version of Cypress. More details are included when running via `cypress run`.\n", "section": "api", "anchors": [ "syntax" ], "path": "/llm/json/chunked/api/node-events/before-run-api.json", "token_estimate": 225 }, { "id": "api/node-events/before-run-api#usage", "doc_id": "api/node-events/before-run-api", "heading": "Usage", "heading_level": 2, "content_markdown": "## Usage\n\nYou can return a promise from the `before:run` event handler and it will be awaited before Cypress proceeds running your specs.\n\n### Log the browser and the number of specs that will be run\n\n* cypress.config.js\n* cypress.config.ts\n\n```\nconst { 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) => { // 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 ) } }) }, },})\n```\n\n```\nimport { 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) => { // 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 ) } }) }, },})\n```\n", "section": "api", "anchors": [ "usage" ], "path": "/llm/json/chunked/api/node-events/before-run-api.json", "token_estimate": 624 }, { "id": "api/node-events/before-run-api#log-the-browser-and-the-number-of-specs-that-will-be-run", "doc_id": "api/node-events/before-run-api", "heading": "Log the browser and the number of specs that will be run", "heading_level": 3, "content_markdown": "### Log the browser and the number of specs that will be run\n\n* cypress.config.js\n* cypress.config.ts\n\n```\nconst { 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) => { // 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 ) } }) }, },})\n```\n\n```\nimport { 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) => { // 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 ) } }) }, },})\n```\n", "section": "api", "anchors": [ "log-the-browser-and-the-number-of-specs-that-will-be-run" ], "path": "/llm/json/chunked/api/node-events/before-run-api.json", "token_estimate": 593 } ] }