fix: do not register CT specific event in e2e mode

circle.yml

@@ -1339,8 +1339,12 @@ jobs:
           name: Build
           command: yarn workspace @cypress/vue build
       - run:
-          name: Run tests
-          command: yarn test-ci
+          name: Run component tests
+          command: yarn test-ci:ct
+          working_directory: npm/vue
+      - run:
+          name: Run e2e tests
+          command: yarn test:ci:e2e
           working_directory: npm/vue
       - store_test_results:
           path: npm/vue/test_results

npm/vue/cypress/plugins/index.js

@@ -7,7 +7,7 @@ const webpackConfig = require('../../webpack.config')
  */
 module.exports = (on, config) => {
   if (config.testingType !== 'component') {
-    throw Error(`This is a component testing project. testingType should be 'component'. Received ${config.testingType}`)
+    return config
   }
 
   if (!webpackConfig.resolve) {

npm/vue/cypress/support/commands.js

@@ -0,0 +1,6 @@
+/// <reference types="cypress" />
+import { mount } from '@cypress/vue'
+
+Cypress.Commands.add('mount', (comp) => {
+  return mount(comp)
+})

npm/vue/cypress/support/index.js

@@ -1 +1,3 @@
 // created automatically when cy:open starts
+
+import './commands'

npm/vue/package.json

@@ -8,6 +8,7 @@
     "build-prod": "yarn build",
     "cy:open": "node ../../scripts/cypress.js open-ct --project ${PWD}",
     "cy:run": "node ../../scripts/cypress.js run-ct --project ${PWD}",
+    "cy:run:e2e": "node ../../scripts/cypress.js run --project ${PWD}",
     "test": "yarn cy:run",
     "watch": "yarn build --watch --watch.exclude ./dist/**/*",
     "test-ci": "node ../../scripts/run-ct-examples.js --examplesList=./examples.env"

npm/vue/src/index.ts

@@ -36,6 +36,16 @@ type CyMountOptions<Props> = Omit<MountingOptions<Props>, 'attachTo'> & {
 let initialInnerHtml = ''
 
 Cypress.on('run:start', () => {
+  // `mount` is designed to work with component testing only.
+  // it assumes ROOT_ID exists, which is not the case in e2e.
+  // if the user registers a custom command that imports `cypress/vue`,
+  // this event will be registered and cause an error when the user
+  // launches e2e (since it's common to use Cypress for both CT and E2E.
+  // https://github.com/cypress-io/cypress/issues/17438
+  if (Cypress.testingType !== 'component') {
+    return
+  }
+
   initialInnerHtml = document.head.innerHTML
   Cypress.on('test:before:run', () => {
     Cypress.vueWrapper?.unmount()