remote-debugging-port cannot be set using ELECTRON_EXTRA_LAUNCH_ARGS

[dg-nvm]

Current behavior:

When set ELECTRON_EXTRA_LAUNCH_ARGS=--remote-debugging-port 40500 is used then nothing happens

BUT

When I change environment.js to use appendSwitch instead, it works:

app.commandLine.appendSwitch('remote-debugging-port', '40500')

Desired behavior:

I can set option via environment variable

Test code to reproduce

set ELECTRON_EXTRA_LAUNCH_ARGS=--remote-debugging-port 40500
cypress open

Cypress should output:
DevTools listening on ws://127.0.0.1:40500/devtools/browser/<UUID>

Versions

Windows 10, Cypress 4.10.0, using builtin Electron in Headed mode

[jennifer-shehane]

Yeah, I don't think we are handling key value pairs correctly in our ELECTRON_EXTRA_LAUNCH_ARGS here. Electron says we need to call the argument like app.commandLine.appendSwitch('remote-debugging-port', '8315'), but I don't see us actually pulling out the value from the key in order to pass these as 2 arguments to appendSwitch. https://www.electronjs.org/docs/api/command-line-switches

The code that handles this is here: https://github.com/cypress-io/cypress/blob/develop/packages/server/lib/environment.js#L71:L71

The test shows it's being called as --remote-debugging-port=40500.

I don't think that appendArgument actually supports key value pairs, the Electron docs even suggest using appendSwitch here instead. https://www.electronjs.org/docs/api/command-line#commandlineappendargumentvalue

[jennifer-shehane]

Opened a PR here #8001

[dg-nvm]

@jennifer-shehane thank you Jennifer for fast reaction. These two differs greatly internally and also they mention added cmdline will be added before switches.

[cypress-bot]

The code for this is done in cypress-io/cypress#8001, but has yet to be released.
We'll update this issue and reference the changelog when it's released.