xparse verbatim with newline

Question

I'm trying to define a simple command using xparse and it's verbatim argument:

\DeclareDocumentCommand\macro{v}{#1}

but see

! LaTeX error: "xparse/verbatim-newline"
!
! Verbatim argument of \macrocode ended by end of line.
!
! See the LaTeX3 documentation for further information.
!
! For immediate help type H <return>.

when the argument is multiple lines of code (i.e., contains a new line):

\macro{This
Is
A
Test}

but it has no problem for something like

  \macro{This    Is    A    Test}

In my case, I need it to work with new lines.

Update:

\documentclass{book}
\usepackage{luatex,xparse}
\directlua{tex.enableprimitives('',tex.extraprimitives())}
\begin{document}

\DeclareDocumentCommand{\macro}{+v}{\directlua{print("\luaescapestring{#1}")}}
\DeclareDocumentCommand{\macroa}{+v}{#1}

\macro{
This
Is
A
Test
}

\macroa{
This
Is
A
Test
}

\end{document}

macro prints "ThisIsATest" without newlines. I need to print Exactly what is passed to the macro. macroa gives fi Thisfi Isfi Afi Testfi.

BTW, here is a MWE of it working but I want to "wrap" the behavior inside a macro for convenience:

\documentclass{book}   
\usepackage{luatex}    
\directlua{tex.enableprimitives('',tex.extraprimitives())}    
\begin{document}

\endlinechar`\^^J%
\catcode`\^^M=13%
\directlua{print("\luaescapestring\expandafter{\detokenize{%
This
Is
A
Test
}}")}%
\catcode`\^^M=5

\end{document}

EXCEPT Some random characters are output to the pdf (In my working example this doesn't happen because, I guess, I'm using a different font encoding).

Answer 1

You get the lines printed in the log file and no output in the PDF with this:

\documentclass{book}
\usepackage{luatex}
\directlua{tex.enableprimitives('',tex.extraprimitives())}

\def\myprint{%
  \begingroup
  \endlinechar`\^^J%
  \catcode`\^^M=13%
  \myprintaux}
\def\myprintaux#1#2{%
  \directlua{print("\luaescapestring\expandafter{\detokenize{#1}}")}\endgroup}

\begin{document}

\myprint
{This
is
a
test
}

\end{document}

You need to use that form (the closing brace must be on a line of its own).

Answer 2

As covered in the xparse documentation, the v argument type is very similar to \verb, and has to be ended within a line. You can grab multiple lines using the 'long' indicator, +:

\DeclareDocumentCommand{\macro}{+v}{#1}

You should note that you will get

This^^MIs^^MA^^MTest

when you grab verbatim here (i.e. you get end-of-line tokens, not \par).