nixpkgs/pkgs/build-support/make-darwin-bundle/default.nix

# given a package with an executable and an icon, make a darwin bundle for
# it. This package should be used when generating launchers for native Darwin
# applications. If the package conatins a .desktop file use
# `desktopToDarwinLauncher` instead.

{ lib, writeShellScript, writeDarwinBundle }:

{ name # The name of the Application file.
, exec # Executable file.
, icon ? "" # Optional icon file.
}:

writeShellScript "make-darwin-bundle-${name}" (''
  function makeDarwinBundlePhase() {
    mkdir -p "${!outputBin}/Applications/${name}.app/Contents/MacOS"
    mkdir -p "${!outputBin}/Applications/${name}.app/Contents/Resources"

    if [ -n "${icon}" ]; then
      ln -s "${icon}" "${!outputBin}/Applications/${name}.app/Contents/Resources"
    fi

    ${writeDarwinBundle}/bin/write-darwin-bundle "${!outputBin}" "${name}" "${exec}"
  }

  preDistPhases+=" makeDarwinBundlePhase"
'')