wsl open command for fish. ref. https://zenn.dev/kaityo256/articles/open_command_on_wsl

open.fish

function open
    if test (count $argv) -eq 0
        explorer.exe .
    else
        if test -f $argv[1]
            cmd.exe /c start (wslpath -w $argv[1]) 2> /dev/null
        else if test -d $argv[1]
            explorer.exe (wslpath -w $argv[1])
        else
            echo "open: $1 : No such file or directory"
        end
    end
end