WatchFileChange does not work when running Cypress in a WSL2 Docker container

[sebgamby]

Hello,

I would like to work with Cypress in interactive mode running in a WSL2 Docker container on my Windows 11 desktop. It works fine with one caveat: Cypress is incapable to detect file changes on the specs.

To give a bit of context:
I am not using a X server such as vcXsrv as it is no longer necessary with the latest WSL improvements.
My Windows build is 22621.1848
Docker Desktop is at version 4.20.1
The output of "wsl --version" is

WSL version: 1.2.5.0
Kernel version: 5.15.90.1
WSLg version: 1.0.51
MSRDC version: 1.2.3770
Direct3D version: 1.608.2-61064218
DXCore version: 10.0.25131.1002-220531-1700.rs-onecore-base2-hyp
Windows version: 10.0.22621.1848

I am running Cypress with this command:

docker run -it -v /run/desktop/mnt/host/wslg/.X11-unix:/tmp/.X11-unix -v /run/desktop/mnt/host/wslg:/mnt/wslg -e DISPLAY=:0 -e WAYLAND_DISPLAY=wayland-0 -e XDG_RUNTIME_DIR=/mnt/wslg/runtime-dir -e PULSE_SERVER=/mnt/wslg/PulseServer -v .:/e2e -w /e2e --entrypoint cypress cypress/included:12.16.0 open --project .

I have tested with the default test spec created by Cypress. I have also checked in the settings that the setting watchFileChanges is set to true.

Please note that I have tested several variations to the environment presented above such as:

• Run in a VSCode DevContainer without environment variables (e.g. DISPLAY)
• Run in a container with environment variable DISPLAY set to host.docker.internal:0.0 and VcXsrv running

Each time, I get the same result: the Cypress window is presented, I can run the test but any modifications to the spec files is undetected and even unavailable until Cypress is restarted.

[warrensplayer]

@sebgamby Cypress uses the node package chokidar to watch for file changes. I did a bit of research and found a potential solution described here: microsoft/WSL#4169 (comment)

Can you try adding the CHOKIDAR_USEPOLLING=true environment variable to your docker run command to see if it fixes your issue?

[sebgamby]

@warrensplayer I have tried it and it works! Thanks a lot! This is going to make my life so much more simpler.