How to make \autocites work as \supercite with square brackets and grouped

Question

I found how to make \supercite with square brackets and grouped at Biblatex supercite with square brackets and grouped

So I add the option autocite=superscript for biblatex package, and get this MWE:

\documentclass{article}

\usepackage[autocite=superscript,citestyle=numeric-comp]{biblatex}


\DeclareCiteCommand{\supercite}[\mkbibsuperscript]
  {\usebibmacro{cite:init}%
   \let\multicitedelim=\supercitedelim
   \iffieldundef{prenote}
     {}
     {\BibliographyWarning{Ignoring prenote argument}}%
   \iffieldundef{postnote}
     {}
     {\BibliographyWarning{Ignoring postnote argument}}%
  \bibopenbracket}%
  {\usebibmacro{citeindex}%
   \usebibmacro{cite:comp}}
  {}
  {\usebibmacro{cite:dump}\bibclosebracket}

\usepackage{filecontents}

\begin{filecontents}{test.bib}
@book{A01,
  author = {Author, A.},
  year = {2001},
  title = {Alpha},
}
@book{B02,
  author = {Buthor, B.},
  year = {2002},
  title = {Bravo},
}
@article{C03,
  author = {Cuthor, C.},
  year = {2003},
  title = {Charlie},
}
\end{filecontents}

\addbibresource{test.bib}

\begin{document}

We are citing \autocites{A01}{B02}{C03} and \autocites{A01}{C03} and \autocites*{A01}{B02}.

\printbibliography

\end{document}

But the number is not grouped. I get [1],[2],[3] instead of [1-3].

Answer 1

The issue here is twofold.

1. You can get better results by moving the brackets into the wrapper command instead of the pre- and post-code and doing the same thing for the multicite command.

2. The multicite commands do not sort or compress citations across different groups. See also https://github.com/plk/biblatex/issues/817 (there are inelegant workarounds available as the last post in the linked discussion shows).

For now, all I can offer is

\documentclass{article}

\usepackage[style=numeric-comp, autocite=superscript]{biblatex}

\newrobustcmd*{\mkbibbracketedsuperscript}[1]{%
  \mkbibsuperscript{\mkbibbrackets{#1}}}

\DeclareCiteCommand{\supercite}[\mkbibbracketedsuperscript]
  {\usebibmacro{cite:init}%
   \let\multicitedelim=\supercitedelim
   \iffieldundef{prenote}
     {}
     {\BibliographyWarning{Ignoring prenote argument}}%
   \iffieldundef{postnote}
     {}
     {\BibliographyWarning{Ignoring postnote argument}}}%
  {\usebibmacro{citeindex}%
   \usebibmacro{cite:comp}}
  {}
  {\usebibmacro{cite:dump}}

\DeclareMultiCiteCommand{\supercites}[\mkbibbracketedsuperscript]
  {\supercite}{\supercitedelim}

\addbibresource{biblatex-examples.bib}

\begin{document}
We are citing \autocites{sigfridsson}{worman}{nussbaum} and \autocites{sigfridsson}{nussbaum} and \autocites*{sigfridsson}{worman}.

We are citing \autocite{sigfridsson,worman,nussbaum} and \autocite{sigfridsson,nussbaum} and \autocite*{sigfridsson,worman}.

\printbibliography
\end{document}