Proposal: Record open devTools in screenshots and video during `cypress run`

With these changes, it will no longer be possible to have opened the dev tools for electron in interactive mode and then have them automatically opened during a run. Also, it’s never been possible to explicitly tells other browsers to open their dev tools.

Add a flag (--dev-tools or --open-dev-tools) that will open the browser dev tools on launch so a debugger in test or app code can hit and pause the run for debugging purposes.

[jennifer-shehane]

This is now possible in all supported browsers with the workaround below. See https://on.cypress.io/browser-launch-api#Modify-browser-launch-arguments

Closing as resolved.

// plugins/index.js
module.exports = (on, config) => {
  on('before:browser:launch', (browser = {}, launchOptions) => {
    // `args` is an array of all the arguments that will
    // be passed to browsers when it launches
    console.log(launchOptions.args) // print all current args

    if (browser.family === 'chromium' && browser.name !== 'electron') {
      // auto open devtools
      launchOptions.args.push('--auto-open-devtools-for-tabs')
    }

    if (browser.family === 'firefox') {
      // auto open devtools
      launchOptions.args.push('-devtools')
    }

    if (browser.name === 'electron') {
      // auto open devtools
      launchOptions.preferences.devTools = true
    }

    // whatever you return here becomes the launchOptions
    return launchOptions
  })
}

[mellis481]

@jennifer-shehane This only appears to work with the Cypress test runner, not when you run Cypress headlessly (as @mjlawrence83 and @rbabayoff mentioned above). IMO automatically opening devtools during cypress open is a slight convenience whereas opening devtools while running Cypress headlessly would be of enormous benefit in situations where the cy.log’ed error isn’t helpful and one needs to troubleshoot an AOT error.

Please advise.