how to use NixOS's Cypress instead of npm's Cypress

_use nixpkgs cypress binary before npms broken copy.md

Should help with avoiding errors like:

No version of Cypress is installed in: /home/rkb/.cache/Cypress/6.2.1/Cypress

Please reinstall Cypress by running: cypress install

----------

Cypress executable not found at: /home/rkb/.cache/Cypress/6.2.1/Cypress/Cypress

----------

Platform: linux (NixOS - )
Cypress Version: 6.2.1

and

Cypress failed to start.

This is usually caused by a missing library or dependency.

The error below should indicate which dependency is missing.

https://on.cypress.io/required-dependencies

If you are using Docker, we provide containers with all required dependencies installed.

----------

Command failed with ENOENT: /home/rkb/.cache/Cypress/6.2.1/Cypress/Cypress --no-sandbox --smoke-test --ping=459
spawn /home/rkb/.cache/Cypress/6.2.1/Cypress/Cypress ENOENT

----------

Platform: linux (NixOS - )
Cypress Version: 6.2.1

todo

EACCES: permission denied, open '/home/rkb/.config/Cypress/cy/production/browsers/chrome-stable/interactive/CypressExtension/background.js'

apply this patch to Cypress from within the shell.nix (or get it upstreamed?) done. Super hacky, but done!

cypress-overlay.nix

# When Cypress starts, it copies some files into `~/.config/Cypress/cy/production/browsers/chrome-stable/interactive/CypressExtension/`
# from the Nix Store, one of which it attempts to modify immediately after.
# As-is, this fails because the copied file keeps the read-only flag it had in
# the Store.
# Luckily, the code responsible is a plain text script that we can easily patch:
final: prev: {
  cypress = prev.cypress.overrideAttrs (oldAttrs: {
    installPhase = let
      old = "copyExtension(pathToExtension, extensionDest)";
      # This has only been tested against Cypress 6.0.0!
      newForChrome =
        "copyExtension(pathToExtension, extensionDest).then(() => fs_1.default.chmodAsync(extensionBg, 0o0644))";
      newForFirefox =
        "copyExtension(pathToExtension, extensionDest).then(() => fs.chmodAsync(extensionBg, 0o0644))";
    in ''
      sed -i 's/${old}/${newForChrome}/' \
          ./resources/app/packages/server/lib/browsers/chrome.js

      sed -i 's/${old}/${newForFirefox}/' \
          ./resources/app/packages/server/lib/browsers/utils.js
    '' + oldAttrs.installPhase;
  });
}

shell.nix

let pkgs = import <nixpkgs> { overlays = [ (import ./cypress-overlay.nix) ]; };
in pkgs.mkShell {
  name = "cypress-example";

  buildInputs = with pkgs; [
    cypress
    (with dotnetCorePackages; combinePackages [ sdk_5_0 net_5_0 ])
    nodejs
  ];

  shellHook = ''
    export CYPRESS_INSTALL_BINARY=0
    export CYPRESS_RUN_BINARY=${pkgs.cypress}/bin/Cypress
  '';
}

In my case I was using Cypress 6.2.1, and I was getting read-only errors for a socket.io file. Instead of trying to find out where in Cypress's installation procedure that was being copied, and changing its permissions, I just find ~/.config/Cypress -exec chmod -v +w {} \; and it's working…

Ah, using the actual store path is a good idea, thanks zeorin!
I've updated the gist with that.

Here's the overlay for Cypress 7.4.0. In my case, both Chromium and Firefox DevEdition work with this overlay.

# When Cypress starts, it copies some files into `~/.config/Cypress/cy/production/browsers/chrome-stable/interactive/CypressExtension/`
# from the Nix Store, one of which it attempts to modify immediately after.
# As-is, this fails because the copied file keeps the read-only flag it had in
# the Store.
# Luckily, the code responsible is a plain text script that we can easily patch:
final: prev: {
  # This has only been tested against Cypress 7.4.0
  cypress = prev.cypress.overrideAttrs (oldAttrs: {
    installPhase = let
      matchForChrome = "yield utils_1.default.copyExtension(pathToExtension, extensionDest);";
      appendForChrome = "yield fs_1.fs.chmodAsync(extensionBg, 0o0644);";

      matchForFirefox = "copyExtension(pathToExtension, extensionDest)";
      replaceForFirefox = "copyExtension(pathToExtension, extensionDest).then(() => fs.chmodAsync(extensionBg, 0o0644))";
    in ''
      sed -i '/${matchForChrome}/a\${appendForChrome}' \
          ./resources/app/packages/server/lib/browsers/chrome.js

      sed -i 's/${matchForFirefox}/${replaceForFirefox}/' \
          ./resources/app/packages/server/lib/browsers/utils.js
    '' + oldAttrs.installPhase;
  });
}

On Cypress 7.5.0, noreferences' fix works, but I run into another error in interactive mode, only the second time I launch the browser in "open" mode:

EACCES: permission denied, unlink '/home/rkb/.config/Cypress/cy/production/browsers/chrome-stable/interactive/CypressExtension/popup.html'

Running chmod u+rw -R ~/.config/Cypress/ lets me get past that error... not sure what to patch to avoid it in the first place.

Here is the overlay variation that also pins the cypess version:

# When Cypress starts, it copies some files into `~/.config/Cypress/cy/production/browsers/chrome-stable/interactive/CypressExtension/`
# from the Nix Store, one of which it attempts to modify immediately after.
# As-is, this fails because the copied file keeps the read-only flag it had in
# the Store.
# Luckily, the code responsible is a plain text script that we can easily patch:
final: prev: {
  cypress = prev.cypress.overrideAttrs (oldAttrs: rec {
    pname = "cypress";
    version = "9.5.0";

    src = prev.fetchzip {
      url = "https://cdn.cypress.io/desktop/${version}/linux-x64/cypress.zip";
      sha256 = "1sjkrx8yv187waly1namcks013apmr73jsr0fpyqyp93ddri8lvc";
    };

    installPhase =
      let
        matchForChrome = "yield utils_1.default.copyExtension(pathToExtension, extensionDest);";
        appendForChrome = "yield fs_1.fs.chmodAsync(extensionBg, 0o0644);";

        matchForFirefox = "copyExtension(pathToExtension, extensionDest)";
        replaceForFirefox = "copyExtension(pathToExtension, extensionDest).then(() => fs.chmodAsync(extensionBg, 0o0644))";
      in
      ''
        sed -i '/${matchForChrome}/a\${appendForChrome}' \
            ./resources/app/packages/server/lib/browsers/chrome.js

        sed -i 's/${matchForFirefox}/${replaceForFirefox}/' \
            ./resources/app/packages/server/lib/browsers/utils.js
      '' + oldAttrs.installPhase;
  });
}

In order to chage the cypress version you need to update the version and the sha256 variables.

NOTE: depending on the version it can happen that the installPhase will also need to be updated

Is there any reason this hasn't been upstreamed yet?

looks like the related issue in Cypress' repo is still open: cypress-io/cypress#18893

I followed all these steps but when I try to run cypress it errors out with :
qemu-x86_64: Could not open '/lib64/ld-linux-x86-64.so.2': No such file or directory

For the record, I just upgraded from Cypress v10.11.0 to v12.1.0 and I had to drop entire installPhase.

So, as for cypress-overlay.nix, before:

## NOTE: This is a Nix overlay file taken and modified from:
##
## https://gist.github.com/r-k-b/2485f977b476aa3f76a47329ce7f9ad4
##
##
## When Cypress starts, it copies some files into
##
## ~/.config/Cypress/cy/production/browsers/chrome-stable/interactive/CypressExtension/
##
## ... from the Nix Store, one of which it attempts to modify immediately
## after. As-is, this fails because the copied file keeps the
## read-only flag it had in the Store.
##
## Luckily, the code responsible is a plain text script that we can
## easily patch:
final: prev: {
  cypress = prev.cypress.overrideAttrs (oldAttrs: rec {
    pname = "cypress";
    version = "10.11.0";

    src = prev.fetchzip {
      url = "https://cdn.cypress.io/desktop/${version}/linux-x64/cypress.zip";
      sha256 = "06mi20jknc52i62l4lq2j1r9ahd7x2bm6vznc2v1flawh1vkvziv";
      ## Note: sha256 is computed via (note the version):
      ##
      ## nix-prefetch-url --unpack https://cdn.cypress.io/desktop/10.11.0/linux-x64/cypress.zip
    };

    installPhase =
      let
        matchForChrome = "yield utils_1.default.copyExtension(pathToExtension, extensionDest);";
        appendForChrome = "yield fs_1.fs.chmodAsync(extensionBg, 0o0644);";

        matchForFirefox = "copyExtension(pathToExtension, extensionDest)";
        replaceForFirefox = "copyExtension(pathToExtension, extensionDest).then(() => fs.chmodAsync(extensionBg, 0o0644))";
      in
      ''
        sed -i '/${matchForChrome}/a\${appendForChrome}' ./resources/app/packages/server/lib/browsers/chrome.js
        sed -i 's/${matchForFirefox}/${replaceForFirefox}/' ./resources/app/packages/server/lib/browsers/utils.js
      '' + oldAttrs.installPhase;
  });
}

... and after:

## NOTE: This is a Nix overlay file taken and modified from:
##
## https://gist.github.com/r-k-b/2485f977b476aa3f76a47329ce7f9ad4
##
##
## When Cypress starts, it copies some files into
##
## ~/.config/Cypress/cy/production/browsers/chrome-stable/interactive/CypressExtension/
##
## ... from the Nix Store, one of which it attempts to modify immediately
## after. As-is, this fails because the copied file keeps the
## read-only flag it had in the Store.
##
## Luckily, the code responsible is a plain text script that we can
## easily patch:
final: prev: {
  cypress = prev.cypress.overrideAttrs (oldAttrs: rec {
    pname = "cypress";
    version = "12.1.0";

    src = prev.fetchzip {
      url = "https://cdn.cypress.io/desktop/${version}/linux-x64/cypress.zip";
      sha256 = "1jbjsgb3msjlx0y6wjvb99n3v009sc0nq19grlad57f2p5y0iy09";
      ## Note: sha256 is computed via (note the version):
      ##
      ## nix-prefetch-url --unpack https://cdn.cypress.io/desktop/12.1.0/linux-x64/cypress.zip
    };
  });
}