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l3build.dtx
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l3build.dtx
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% \iffalse
%
% File l3build.dtx (C) Copyright 2014-2017 The LaTeX3 Project
%
% It may be distributed and/or modified under the conditions of the
% LaTeX Project Public License (LPPL), either version 1.3c of this
% license or (at your option) any later version. The latest version
% of this license is in the file
%
% http://www.latex-project.org/lppl.txt
%
% This file is part of the "l3build bundle" (The Work in LPPL)
% and all files in that bundle must be distributed together.
%
% -----------------------------------------------------------------------
%
% The development version of the bundle can be found at
%
% https://github.com/latex3/l3build
%
% for those people who are interested.
%
%<*driver>
\RequirePackage{expl3}
\documentclass[full]{l3doc}
\renewcommand\partname{Part}
\usepackage{multicol,needspace}
\makeatletter
\addtolength\columnsep{1em}
\renewcommand\columnseprule{0.4pt}
\def\@starttoc#1{%
\begin{multicols}{2}
\small
\makeatletter
\@input{\jobname.#1}%
\expandafter\newwrite\csname tf@#1\endcsname
\immediate\openout \csname tf@#1\endcsname \jobname.#1\relax
\@nobreakfalse
\end{multicols}}
\makeatother
\newenvironment{buildcmd}[1]{%
\bigskip\par\noindent\hspace{-\parindent}%
\fbox{\ttfamily \textcolor[gray]{0.5}{\$} texlua build.lua #1}%
\nopagebreak\smallskip\nopagebreak\par\nopagebreak\noindent\ignorespaces
}
{}
\makeatletter
\newcommand\luavar[1]{\@ifundefined{lua_#1}{\ERROR}{\texttt{\@nameuse{lua_#1}}}}
\newcommand\luavarset[3]{\@namedef{lua_#1}{#2}}
\newcommand\luavarseparator{}
\makeatother
\def\allluavars{
\luavarset{module}{""}{The name of the module}
\luavarset{bundle}{""}{The name of the bundle in which the module belongs (where relevant)}
\luavarset{ctanpkg}{module/bundle}{Name of the CTAN package matching this module}
\luavarseparator
\luavarset{modules}{\{\}}{The list of all modules in a bundle (when not auto-detecting)}
\luavarset{exclmodules}{\{\}}{Directories to be excluded from automatic module detection}
\luavarseparator
\luavarset{maindir} {"."} {Top level directory for the module/bundle}
\luavarset{docfiledir} {"."} {Directory containing documentation files}
\luavarset{sourcfiledir}{"."} {Directory containing source files}
\luavarset{supportdir} {maindir .. "/support"} {Directory containing general support files}
\luavarset{testfiledir}{"./testfiles"} {Directory containing test files}
\luavarset{testsuppdir}{testfiledir .. "/support"}{Directory containing test-specific support files}
\luavarseparator
\luavarset{builddir} {maindir .. "/build"} {Directory for building and testing}
\luavarset{distribdir}{builddir .. "/distrib"}{Directory for generating distribution structure}
\luavarset{localdir} {builddir .. "/local"} {Directory for extracted files in \enquote{sandboxed} \TeX{} runs}
\luavarset{testdir} {builddir .. "/test"} {Directory for running tests}
\luavarset{typesetdir}{builddir .. "/doc"} {Directory for building documentation}
\luavarset{unpackdir} {builddir .. "/unpack"} {Directory for unpacking sources}
\luavarseparator
\luavarset{ctandir}{distribdir .. "/ctan"}{Directory for organising files for CTAN}
\luavarset{tdsdir} {distribdir .. "/tds"} {Directory for organised files into TDS structure}
\luavarset{tdsroot}{"latex"}{Root directory of the TDS structure for the bundle/module to be installed into}
\luavarseparator
\luavarset{bibfiles} {\{"*.bib"\}}{\BibTeX{} database files}
\luavarset{binaryfiles} {\{"*.pdf", "*.zip"\}}{Files to be added in binary mode to zip files}
\luavarset{bstfiles} {\{"*.bst"\}}{\BibTeX{} style files}
\luavarset{checkfiles} {\{~\}}{Extra files unpacked purely for tests}
\luavarset{checksuppfiles} { }{Files needed for performing regression tests}
\luavarset{cmdchkfiles} {\{\}}{Files need to perform command checking (\cls{l3doc}-based documentation only)}
\luavarset{cleanfiles} {\{"*.log", "*.pdf", "*.zip"\}}{Files to delete when cleaning}
\luavarset{demofiles} {\{\}}{Files which show how to use a module}
\luavarset{docfiles} {\{\}}{Files which are part of the documentation but should not be typeset}
\luavarset{excludefiles} {\{"*\string~"\}}{Files to ignore entirely (default for Emacs backup files)}
\luavarset{installfiles} {\{"*.sty","*.cls"\}}{Files to install to the \TeX{} tree and similar task}
\luavarset{makeindexfiles} {\{"*.ist"\}}{MakeIndex files to be included in a TDS-style zip}
\luavarset{sourcefiles} {\{"*.dtx", "*.ins"\}}{Files to copy for unpacking}
\luavarset{textfiles} {\{"*.md", "*.txt"\}}{Plain text files to send to CTAN as-is}
\luavarset{typesetdemofiles} {\{\}}{Files to typeset before the documentation for inclusion in main documentation files}
\luavarset{typesetfiles} {\{"*.dtx"\}}{Files to typeset for documentation}
\luavarset{typesetsuppfiles} {\{\}}{Files needed to support typesetting when \enquote{sandboxed}}
\luavarset{typesetsourcefiles}{\{\}}{Files to copy to unpacking when typesetting.}
\luavarset{unpackfiles} {\{"*.ins"\}}{Files to run to perform unpacking.}
\luavarset{unpacksuppfiles} {\{\}}{Files needed to support unpacking when \enquote{sandboxed}}
\luavarset{versionfiles} {\{"*.dtx"\}}{Files for automatic version editing}
\luavarseparator
\luavarset{bakext}{".bak"}{Extension of backup files}
\luavarset{dviext}{".dvi"}{Extension of DVI files}
\luavarset{lvtext}{".lvt"}{Extension of test files}
\luavarset{tlgext}{".tlg"}{Extension of test file output}
\luavarset{lveext}{".lve"}{Extension of auto-generating test file output}
\luavarset{logext}{".log"}{Extension of checking output, before processing it into a \texttt{.tlg}}
\luavarset{pdfext}{".pdf"}{Extension of PDF file for checking and saving}
\luavarset{psext} {".ps"} {Extension of PostScript files}
\luavarseparator
\luavarset{checkdeps} {\{\}}{List of dependencies for running checks}
\luavarset{typesetdeps}{\{\}}{List of dependencies for typesetting docs}
\luavarset{unpackdeps} {\{\}}{List of dependencies for unpacking}
\luavarseparator
\luavarset{checkengines}{\{"pdftex", "xetex", "luatex"\}}{Engines to check with \texttt{check} by default}
\luavarset{stdengine} {"pdftex"}{Engine to generate \texttt{.tlg} file from}
\luavarset{checkformat} {"latex"} {Format to use for tests}
\luavarseparator
\luavarset{typesetexe}{"pdflatex"}{Executable for compiling \texttt{doc(s)}}
\luavarset{unpackexe} {"tex"} {Executable for running \texttt{unpack}}
\luavarset{zipexe} {"zip"} {Executable for creating archive with \texttt{ctan}}
\luavarseparator
\luavarset{checkopts} {"-interaction=nonstopmode"}{Options based to engine when running checks.}
\luavarset{cmdchkopts} {"-interaction=batchmode"} {Options based to engine when running command checks.}
\luavarset{typesetopts}{"-interaction=nonstopmode"}{Options based to engine when typesetting.}
\luavarset{unpackopts} {""} {Options based to engine when unpacking.}
\luavarset{zipopts} {"-v -r -X"} {Options based to zip program.}
\luavarseparator
\luavarset{checksearch} {true}{Switch to search the system \texttt{texmf} for during checking}
\luavarset{typesetsearch}{true}{Switch to search the system \texttt{texmf} for during typesetting}
\luavarset{unpacksearch} {true}{Switch to search the system \texttt{texmf} for during unpacking}
\luavarseparator
\luavarset{glossarystyle}{"gglo.ist"}{MakeIndex style file for glossary/changes creation}
\luavarset{indexstyle} {"gind.ist"}{MakeIndex style for index creation}
\luavarseparator
\luavarseparator
\luavarset{biberexe} {"biber"} {Biber executable}
\luavarset{biberopts} {""} {Biber options}
\luavarset{bibtexexe} {"bibtex8"} {\BibTeX{} executable}
\luavarset{bibtexopts} {"-W"} {\BibTeX{} options}
\luavarset{makeindexexe} {"makeindex"}{MakeIndex executable}
\luavarset{makeindexopts}{""} {MakeIndex options}
\luavarseparator
\luavarset{forcecheckepoch}{"true"} {Force epoch when running tests}
\luavarset{forcedocepoch} {"false"} {Force epoch when typesetting}
\luavarseparator
\luavarset{asciiengines}{\{"pdftex"\}}{Engines which should log as sure ASCII}
\luavarset{checkruns} {1} {Number of runs to complete for a test before comparing the log}
\luavarset{epoch} {1463734800} {Epoch (Unix date) to set for test runs}
\luavarset{maxprintline}{79} {Length of line to use in log files}
\luavarset{packtdszip} {false} {Switch to build a TDS-style zip file for CTAN}
\luavarset{scriptname} {"build.lua"} {Name of script used in dependencies}
\luavarset{typesetcmds} {""} {Instructions to be passed to \TeX{} when doing typesetting.}
\luavarset{typsetcycles}{3} {Number of cycles of typesetting to carry out.}
\luavarset{versionform} {""} {Nature of version strings for auto-replacement.}
\luavarset{recordstatus}{false} {Switch to include error level from test runs in \texttt{.tlg} files}
}
\allluavars
\newcommand\luavartypeset{%
\begingroup
\frenchspacing
\renewcommand\luavarset[3]{
\texttt{##1} & \texttt{##2} & ##3 \\
}
\renewcommand\luavarseparator{\midrule}
\setlength\LTleft{-0.21\linewidth}
\begin{longtable}{@{}%
>{\small}
p{0.18\linewidth}
@{\hspace{0.03\linewidth}}
>{\footnotesize\hangindent=1em}
p{0.34\linewidth}
@{\hspace{0.03\linewidth}}
>{\small\raggedright\arraybackslash}
p{0.63\linewidth}
@{}}
\toprule
Variable & Default & Description \\
\midrule\endhead
\allluavars
\bottomrule
\end{longtable}
\endgroup
}
\newcommand\code{\texttt}
\newcommand\var{\texttt}
\usepackage[procnames]{listings}
\lstset{
basicstyle=\ttfamily\small,
numbers=left,
numberstyle={\tiny\color[gray]{0.4}},
}
\usepackage{shortvrb}
\usepackage{enumitem}
\usepackage{longtable}
\MakeShortVerb\|
\begin{document}
\DocInput{\jobname.dtx}
\end{document}
%</driver>
% \fi
%
% \title{^^A
% The \pkg{l3build} package\\ Checking and building packages^^A
% }
%
% \author{^^A
% The \LaTeX3 Project\thanks
% {^^A
% E-mail:
% \href{mailto:latex-team@latex-project.org}
% {latex-team@latex-project.org}^^A
% }^^A
% }
%
% \date{Released 2017/12/06}
%
% \maketitle
% \tableofcontents
%
% \begin{documentation}
%
% \section{The \pkg{l3build} system}
%
% \subsection{Introduction}
%
% The \pkg{l3build} system is a Lua script for building \TeX{} packages, with particular emphasis on regression testing.
% It is written in cross-platform Lua code, so can be used by any modern \TeX{} distribution with the |texlua| interpreter.
% A package for building with \pkg{l3build} can be written in any \TeX\ dialect; its defaults are set up for \LaTeX\ packages written in the DocStrip style. (Caveat: minimal testing has yet been performed for non-\LaTeX{} packages.)
%
% Test files are written as standalone \TeX{} documents using the |regression-test.tex| setup file; documentation on writing these tests is discussed in Section~\ref{sec:writing-tests}.
%
% The |l3build.lua| script is not designed to be executed directly; each package will define its own |build.lua| script as a driver file which both sets variables (such as the name of the package) and then calls the main |l3build.lua| script internally.
%
% \pagebreak[2]
% A standard package layout might look something like the following:
% \begin{Verbatim}[fontsize=\small]
% abc/
% abc.dtx
% abc.ins
% build.lua
% README.md
% support/
% testfiles/
% \end{Verbatim}
% Most of this should look fairly self-explanatory.
% The top level |support/| directory (optional) would contain any necessary files for compiling documentation, running regression tests, and so on.
%
% The \pkg{l3build} system is also capable of building and checking \emph{bundles} of packages.
% To avoid confusion, we refer to either a standalone package or a package within a bundle as a \emph{module}.
%
% For example, within the \LaTeX3 project we have the \textsf{l3packages} bundle which contains the \textsf{xparse}, \textsf{xtemplate}, etc., modules.
% These are all built and distributed as one bundle for installation, distribution \emph{via} CTAN and so forth.
%
% Each module in a bundle will have its own build script, and a bundle build script brings them all together.
% A standard bundle layout would contain the following structure.
% \begin{Verbatim}
% mybundle/
% build.lua
% support/
% yyy/ zoo/
% build.lua build.lua
% README.md README.md
% testfiles/ testfiles/
% yyy.dtx zoo.dtx
% yyy.ins zoo.ins
% \end{Verbatim}
% All modules within a bundle must use the same build script name.
%
% In a small number of cases, the name used by CTAN for a module or bundle is
% different from that used in the installation tree. For example, the \LaTeXe{}
% kernel is called \pkg{latex-base} by CTAN but is located inside
% \texttt{\meta{texmf}/tex/latex/base}. This can be handled by using
% \var{ctanpkg} for the name required by CTAN to override the standard
% value.
%
% The |testfiles/| folder is local to each module, and its layout consists of a series of regression tests with their outputs.
% \begin{Verbatim}
% testfiles/
% test1.lvt
% test1.tlg
% ...
% support/
% my-test.cls
% \end{Verbatim}
% Again, the |support/| directory contains any files necessary to run some or all of these tests.
%
% When the build system runs, it creates a directory |build/| for various unpacking, compilation, and testing purposes.
% For a module, this build folder can be in the main directory of the package itself, but for a bundle it should be common for the bundle itself and for all modules within that bundle.
% A |build/| folder can be safety deleted; all material within is re-generated for each command of the \pkg{l3build} system.
%
% \subsection{Main build commands}
%
% In the working directory of a bundle or module, the following commands can be executed:
% \begin{itemize}[noitemsep]\ttfamily
% \item check
% \item check \meta{name(s)}
% \item cmdcheck
% \item clean
% \item ctan
% \item doc \meta{name(s)}
% \item install
% \item save \meta{name(s)}
% \item setversion
% \item unpack
% \end{itemize}
% These commands are described below.
%
% As well as these commands, the system recognises the options
% \begin{itemize}
% \item \texttt{--date} (\texttt{-d}) Date to use when setting version
% data
% \item \texttt{--engine} (\texttt{-e}) Sets the engine to use for
% testing
% \item \texttt{--force} (\texttt{-f}) Force checks to run even if sanity
% checks fail, \emph{e.g.}~when \texttt{--engine} is not given in
% \luavar{checkengines}
% \item \texttt{--halt-on-error} (\texttt{-H}) Specifies that checks
% should stop as soon as possible, rather than running all requested
% tests; the difference file is printed in the terminal directly in the case of failure
% \item \texttt{--pdf} (\texttt{-p}) Test PDF file against a reference
% version rather than using a log comparison
% \item \texttt{--quiet} (\texttt{-q}) Suppresses output from unpacking
% \item \texttt{--textfiledir} (\texttt{-t}) Select a specific set of tests
% \item \texttt{--version} (\texttt{-v}) Version string to use when setting
% version data
% \end{itemize}
%
% \begin{buildcmd}{check}
% The |check| command runs the entire test suite.
% This involves iterating through each \texttt{.lvt} file in the test directory (specified by the \var{testfiledir} variable), compiling each test in a \enquote{sandbox} (a directory specified by \var{testdir}), and comparing the output against each matching predefined \texttt{.tlg} file.
%
% If changes to the package or the typesetting environment have affected the results, the check for that file fails.
% A |diff| of the expected to actual output should then be inspected to determine the cause of the error; it is located in the \var{testdir} directory (default \luavar{testdir}).
%
% On Windows, the |diff| program is not available and so |fc| is used instead
% (generating an |.fc| file). Setting the environmental variables |diffexe|
% and |diffext| can be used to adjust the choice of comparison made: the standard
% values are
% \begin{itemize}
% \item[Windows] |diffext = fc|, |diffexe = fc /n|
% \item[*nix] |diffext = diff|, |diffexe = diff -c --strip-trailing-cr|
% \end{itemize}
%
% The following files are moved into the \enquote{sandbox} for the |check| process:
% \begin{itemize}
% \item all \var{installfiles} after unpacking;
% \item all \var{checkfiles} after unpacking;
% \item any files in the directory \var{testsuppdir};
% \item any files that match \var{checksuppfiles} in the \var{supportdir}.
% \end{itemize}
% This range of possibilities allow sensible defaults but significant flexibility for defining your own test setups.
%
% Checking can be performed with any or all of the `engines' \texttt{pdftex}, \texttt{xetex}, and \texttt{luatex}.
% By default, each test is executed with all three, being compared against the \texttt{.tlg} file produced from the \var{pdftex} engine (these defaults are controlled by the |checkengines| and |stdengine| variable respectively).
% The format used for tests can be altered by setting \var{checkformat}: the default setting \texttt{latex} means that tests are run using \emph{e.g.}~\texttt{pdflatex}, whereas setting to \texttt{plain} will run tests using \emph{e.g.}~\texttt{pdftex}.
% (Currently, this should be one of \texttt{latex} or \texttt{plain}.)
% To perform the check, the engine typesets each test \var{checkruns} times.
% More detail on this in the documentation on |save|.
% Options passed to the binary are defined in the variable \var{checkopts}.
%
% By default, |texmf| trees are searched for input files when checking. This can be disabled by setting \var{checksearch} to |false|: isolation provides confidence that the tests cannot accidentally be running with incorrect files installed in the main distribution or |hometexmf|.
% \end{buildcmd}
%
%
% \begin{buildcmd}{check \meta{name(s)}}
% Checks only the test \texttt{\meta{name(s)}.lvt}.
% All engines specified by \var{checkengines} are tested unless the command
% line option \texttt{--engine} (or \texttt{-e}) has been given to limit
% testing to a single engine. Normally testing is preceded by unpacking
% source files and copying the result plus any additional support to the
% test directory: this may be skipped using the \texttt{-s} option.
% \end{buildcmd}
%
% \begin{buildcmd}{check -p}
% Rather than the log-based checking carried out by the standard
% |check| target, running with the |-p| option carries out a binary
% comparison of the PDF files produced by typesetting against those
% saved in \var{testfiledir}.
%
% This functionality requires \TeX{} Live 2016 or later as it needs support
% from the engines not available in earlier releases.
% \end{buildcmd}
%
% \begin{buildcmd}{cmdcheck}
% For \cls{l3doc}-based sources, allows checking that the commands defined in the code part (by \var{cmdchkfiles}) are documented in the description part.
% This is performed by passing the |check| option to the \cls{l3doc} class, typesetting the file(s) to check with engine \var{stdengine} with options \var{cmdchkopts}, and checking the resultant |.cmds| file(s).
% Dependencies are specified also with \var{checkdeps}.
% \end{buildcmd}
%
%
% \begin{buildcmd}{clean}
% This command removes all temporary files used for package bundling and regression testing.
% In the standard layout, these are all files within the directories defined by \var{localdir}, \var{testdir}, \var{typesetdir} and \var{unpackdir}, as well as all files defined in the \var{cleanfiles} variable in the same directory as the script.
% The defaults are |.pdf| files from typesetting (|doc|) and |.zip| files from bundling (|ctan|).
% \end{buildcmd}
%
%
% \begin{buildcmd}{ctan}
% Creates an archive of the package and its documentation, suitable for uploading to CTAN
% The archive is compiled in \var{distribdir}, and if the results are successful the resultant |.zip| file is moved into the same directory as the build script.
% If \var{packtdszip} is set true then the building process includes a |.tds.zip| file containing the `\TeX\ Directory Structure' layout of the package or bundle.
% The archive therefore may contain two `views' of the package:
% \begin{Verbatim}
% abc.zip/
% abc/
% abc.dtx
% abc.ins
% abc.pdf
% README.md
% abc.tds.zip/
% doc/latex/abc/
% abc.pdf
% README.md
% source/latex/abc/
% abc.dtx
% abc.ins
% tex/latex/abc/
% abc.sty
% \end{Verbatim}
% The files copied into the archive are controlled by a number of variables.
% The `root' of the TDS structure is defined by \var{tdsroot}, which is \luavar{tdsroot} by default. Plain users would redefine this to |"plain"| (or perhaps |"generic"|), for example.
% The build process for a |.tds.zip| file currently assumes a `standard'
% structure in which all extracted files should be placed inside the |tex|
% tree in a single directory, as shown above. If the module includes any
% \BibTeX{} or MakeIndex styles these will be placed in the appropriate
% subtrees.
%
% \pagebreak[2]
% The |doc| tree is constructed from:
% \begin{itemize}
% \item all files matched by \var{demofiles},
% \item all files matched by \var{docfiles},
% \item all files matched by \var{typesetfiles} with their extension replaced with |.pdf|,
% \item all files matched by \var{textfiles},
% \item all files matched by \var{bibfiles}.
% \end{itemize}
% The |source| tree is constructed from all files matched by \var{typesetfiles} and \var{sourcefiles}.
% The |tex| tree from all files matched by \var{installfiles}.
%
% Files that should always be excluded from the archive are matched against the \var{excludefiles} variable; by default this is \luavar{excludefiles}, which match Emacs' autosave files.
%
% Binary files should be specified with the \var{binaryfiles} variable (default \luavar{binaryfiles}); these are added to the zip archive without normalising line endings (text files are automatically converted to Unix-style line endings).
%
% To create the archive, by default the binary \var{zipexe} is used (\luavar{zipexe}) with options \var{zipopts} (|-v -r -X|). The intermediate build directories \var{ctandir} and \var{tdsdir} are used to construct the archive.
% \end{buildcmd}
%
%
% \begin{buildcmd}{doc}
% Compiles documentation files in the \var{typesetdir} directory.
% In the absence of one or more file names, all documentation is typeset;
% a file list may be given at the command line for selective typesetting.
% If the compilation is successful the |.pdf| is moved back into the main directory.
%
% The documentation compilation is performed with the \var{typesetexe} binary (default \texttt{pdflatex}), with options \var{typesetopts}.
% Additional \TeX{} material defined in \var{typesetcmds} is passed to the document (e.g., for writing |\\PassOptionsToClass{l3doc}{letterpaper}|, and so on---note that backslashes need to be escaped in Lua strings).
%
% Files that match |typesetsuppfiles| in the |support| directory (|supportdir|) are copied into the |build/local| directory (|localdir|) for the typesetting compilation process.
% Additional dependencies listed in the \var{typesetdeps} variable (empty by default) will also be installed.
%
% Source files specified in \var{sourcefiles} and \var{typesetsourcefiles}
% are unpacked before the typesetting takes place. (In most cases
% \var{typesetsourcefiles} will be empty, but may be used where there are
% files to unpack \emph{only} for typesetting.)
%
% If \var{typesetsearch} is \code{true} (default), standard \texttt{texmf} search trees are used in the typesetting compilation. If set to false, \emph{all} necessary files for compilation must be included in the |build/local| sandbox.
%
% \end{buildcmd}
%
% \begin{buildcmd}{doc \meta{name(s)}}
% Typesets only the files with the \meta{name(s)} given, which should be the
% root name without any extension.
% \end{buildcmd}
%
% \begin{buildcmd}{install}
% Copies all package files (defined by \var{installfiles}) into the user's home \texttt{texmf} tree in the form of the \TeX\ Directory Structure.
% \end{buildcmd}
%
% \begin{buildcmd}{save \meta{name(s)}}
% This command runs through the same execution as |check| for a specific test(s) \texttt{\meta{name(s)}.lvt}.
% This command saves the output of the test to a |.tlg| file.
% This file is then used in all subsequent checks against the \texttt{\meta{name}.lvt} test.
%
% If the \texttt{--engine} (or \texttt{-e}) is specified (one of |pdftex|, |xetex|, or |luatex|), the saved output is stored in \texttt{\meta{name}.\meta{engine}.tlg}. This is necessary if running the test through a different engine produces a different output.
% A normalisation process is performed when checking to avoid common differences such as register allocation; full details are listed in section~\ref{sec:norm}.
%
% If the \var{recordstatus} variable is set \var{true}, additional information
% will be added to the \texttt{.tlg} to record the \enquote{exit status} of the
% typesetting compilation of the \texttt{.lvt} file. If the typesetting compilation
% completed without throwing an error (due to \TeX\ programming errors, for example),
% the \enquote{exit status} is zero, else non-zero.
% \end{buildcmd}
%
% \begin{buildcmd}{save -p \meta{name(s)}}
% This version of |save| will store the PDF files produced from
% \texttt{\meta{name(s)}.lvt} in addition to the |.tlg| file, and thus allows
% binary comparison of the result of typesetting.
%
% This functionality requires \TeX{} Live 2016 or later as it needs support
% from the engines not available in earlier releases.
% \end{buildcmd}
%
% \begin{buildcmd}{setversion}
% Modifies the content of files specified by |versionfiles| to allow
% automatic updating of the file date and version. The latter are
% specified using the |-d| and |-v| command line options and if not
% given will default to the current date in ISO format (YYYY-MM-DD) and |-1|,
% respectively. As detailed below, the standard set up has no search pattern
% defined for this target and so no action will be taken \emph{unless}
% a version type for substitution is set up (using \var{versionform} or
% by defining a custom function).
% \end{buildcmd}
%
% \begin{buildcmd}{unpack}
% This is an internal target that is normally not needed on user level.
% It unpacks all files into the directory defined by \var{unpackdir}. This occurs before other build commands such as |doc|, |check|, etc.
%
% The unpacking process is performed by executing the \var{unpackexe} (default \texttt{tex}) with options \var{unpackopts} on all files defined by the \var{unpackfiles} variable; by default, all files that match \luavar{unpackfiles}.
%
% If additional support files are required for the unpacking process, these can be enumerated in the \var{unpacksuppfiles} variable.
% Dependencies for unpacking are defined with \var{unpackdeps}.
%
% By default this process allows files to be accessed in all standard |texmf| trees; this can be disabled by setting \var{unpacksearch} to |false|.
% \end{buildcmd}
%
% \subsection{Example build scripts}
%
% An example of a standalone build script for a package that uses self-contained |.dtx| files is shown in Figure~\ref{fig:breqn}.
% Here, the |module| only is defined, and since it doesn't use |.ins| files so the variable \var{unpackfiles} is redefined to run |tex| on the |.dtx| files instead to generate the necessary |.sty| files.
% There are some PDFs in the repository that shouldn't be part of a CTAN submission, so they're explicitly excluded, and here unpacking is done `quietly' to minimise console output when building the package.
% Finally, because this is a standalone package, we assume that \pkg{l3build} is installed in the main \TeX{} distribution and find the Lua script by searching for it.
%
% \begin{figure}[!b]
% \begin{lstlisting}[frame=single,language={[5.2]Lua},gobble = 6]
% #!/usr/bin/env texlua
%
% -- Build script for breqn
%
% module = "breqn"
%
% unpackfiles = {"*.dtx"}
% excludefiles = {"*/breqn-abbr-test.pdf",
% "*/eqbreaks.pdf"}
% unpackopts = "-interaction=batchmode"
%
% kpse.set_program_name("kpsewhich")
% dofile(kpse.lookup("l3build.lua"))
% \end{lstlisting}
% \caption{The build script for the \pkg{breqn} package.}
% \label{fig:breqn}
% \end{figure}
%
% An example of a bundle build script for \pkg{l3packages} is shown in Figure~\ref{fig:bundle}.
% Note for \LaTeX3 we use a common file to set all build variables in one place, and the path to the |l3build.lua| script is hard-coded so we always use our own most recent version of the script.
% An example of an accompanying module build script is shown in Figure~\ref{fig:module}.
%
% \begin{figure}[p]
% \begin{lstlisting}[frame=single,language={[5.2]Lua},gobble = 6]
% #!/usr/bin/env texlua
%
% -- Build script for LaTeX3 "l3packages" files
%
% -- Identify the bundle: there is no module as this is the "driver"
% bundle = "l3packages"
%
% -- Location of main directory: use Unix-style path separators
% maindir = ".."
%
% -- Load the common build code: this is the one place that a path
% -- needs to be hard-coded
% dofile (maindir .. "/l3build/l3build-config.lua")
% dofile (maindir .. "/l3build/l3build.lua")
% \end{lstlisting}
% \caption{The build script for the \pkg{l3packages} bundle.}
% \label{fig:bundle}
% \end{figure}
%
% \begin{figure}[p]
% \begin{lstlisting}[frame=single,language={[5.2]Lua},gobble = 6]
% #!/usr/bin/env texlua
%
% -- Build script for LaTeX3 "xparse" files
%
% -- Identify the bundle and module:
% bundle = "l3packages"
% module = "xparse"
%
% -- Location of main directory: use Unix-style path separators
% -- Should match that defined by the bundle.
% maindir = "../.."
%
% -- Load the common build code: this is the one place that a path
% -- needs to be hard-coded
% dofile (maindir .. "/l3build/l3build-config.lua")
% dofile (maindir .. "/l3build/l3build.lua")
% \end{lstlisting}
% \caption{The build script for the \pkg{xparse} module.}
% \label{fig:module}
% \end{figure}
%
% \begin{figure}[p]
% \begin{lstlisting}[frame=single,gobble = 6]
% @echo off
% texlua build.lua %*
% \end{lstlisting}
% \caption{Windows batch file wrapper for running the build process.}
% \label{fig:batch}
% \end{figure}
%
% Under a Unix-like platform, you may wish to run `|chmod +x build.lua|' on these files, which allows a simpler command line use. Instead of writing\\
% \hspace*{2\parindent}|texlua build.lua check|\\ for example, you would simply write\\
% \hspace*{2\parindent}|./build.lua check|\\
% instead. (Or even omit the |./| depending on your path settings.)
% Windows users can achieve a similar effect by creating a file |build.bat| as show in Figure~\ref{fig:batch}.
%
% \subsection{Variables}
%
% This section lists all variables defined in the |l3build.lua| script that are available for customisation.
%
% \luavartypeset
%
% \subsection{Multiple sets of tests}
%
% In most cases, a single set of tests will be appropriate for the module, with
% a common set of configuration settings applying. However, there are situations
% where you may need entirely independent sets of tests which have different
% setting values, for example using different formats or where the entire set
% will be engine-dependent. To support this, \pkg{l3build} offers the |--testfiledir|
% (|-t|) command line option. When this is given with a directory argument it
% overrides the \var{testfiledir} variable. Moreover, before the tests are run,
% \pkg{l3build} will read |config.lua| within the directory (if available). This
% should comprise a list of settings which apply to the tests in place of those in
% the main build script.
%
% For example, for the core \LaTeXe{} tests the main test files are contained
% in a directory |testfiles| and have \var{checksearch} set \var{false}. To test
% font loading for \XeTeX{} and \LuaTeX{} there are a second set of tests in
% |testfiles-TU| which use the short |config.lua| file shown in
% Figure~\ref{fig:testfiledir}. These additional tests are then run using
% |texlua build.lua check --testfiledir=testfiles-TU|.
% \begin{figure}
% \begin{lstlisting}[frame=single,language={[5.2]Lua},gobble = 6]
% -- Special config for these tests
% checksearch = true
% checkengines = {"xetex","luatex"}
% \end{lstlisting}
% \caption{The build script for the \pkg{xparse} module.}
% \label{fig:testfiledir}
% \end{figure}
%
% \subsection{Dependencies}
%
% If you have multiple packages that are developed separately but still interact in some way, it's often desirable to integrate them when performing regression tests.
% For \LaTeX3, for example, when we make changes to \pkg{l3kernel} it's important to check that the tests for \pkg{l3packages} still run correctly, so it's necessary to include the \pkg{l3kernel} files in the build process for \pkg{l3packages}.
%
% In other words, \pkg{l3packages} is \emph{dependent} on \pkg{l3kernel}, and this is specified in \pkg{l3build} by setting appropriately the variables \texttt{checkdeps}, \texttt{typesetdeps}, and \texttt{unpackdeps}.
% The relevant parts of the \LaTeX3 repository is structured as the following.
% \Needspace{3\baselineskip}
% \begin{Verbatim}
% l3/
% l3kernel/
% build.lua
% expl3.dtx
% expl3.ins
% ...
% testfiles/
% l3packages/
% build.lua
% xparse/
% build.lua
% testfiles/
% xparse.dtx
% xparse.ins
% support/
% \end{Verbatim}
% For \LaTeX3 build files, |maindir| is defined as top level folder |l3|, so all support files are located here, and the build directories will be created there.
% To set \pkg{l3kernel} as a dependency of \pkg{l3package}, within |l3packages/xparse/build.lua| the equivalent of the following is set:
% \begin{Verbatim}
% maindir = "../.."
% checkdeps = {maindir .. "/l3kernel"}
% \end{Verbatim}
% This ensures that the \pkg{l3kernel} code is included in all processes involved in unpacking and checking and so on.
% The name of the script file in the dependency is set with the |scriptname| variable; by default these are |"build.lua"|.
%
% \subsection{Non-standard source layouts}
%
% A variety of source layouts are supported. In general, a \enquote{flat}
% layout with all source files \enquote{here} is most convenient. However,
% \pkg{l3build} supports placement of both code and documentation source
% files in other locations using the \var{sourcefiledir} and \var{docfiledir}
% variables. For pre-built trees, the glob syntax |**/*| may be useful in these
% cases: this enables recursive searching in the appropriate tree locations.
%
% \subsection{Output normalisation}
% \label{sec:norm}
%
% To allow test files to be used between different systems (\emph{e.g.}~when
% multiple developers are involved in a project), the log files are normalised
% before comparison during checking. This removes some system-dependent
% data but also some variations due to different engines. This normalisation
% consists of two parts: removing (\enquote{ignoring}) some lines and modifying
% others to give consistent test. Currently, the following types of line are
% ignored:
% \begin{itemize}
% \item Lines before the \cs{START}, after the \cs{END} and within
% \cs{OMIT}/\cs{TIMO} blocks
% \item Entirely blank lines, including those consisting only of spaces.
% \item Lines containing file dates in format
% \texttt{\meta{yyyy}/\meta{mm}/\meta{dd}}.
% \item Lines starting \cs{openin} or \cs{openout}.
% \end{itemize}
% Modifications made in lines are:
% \begin{itemize}
% \item Removal spaces at the start of lines.
% \item Removal of |./| at start of file names.
% \item Standardisation of the list of units known to \TeX{} (\pdfTeX{}
% and \LuaTeX{} add a small number of additional units which are not
% known to \TeX90 or \XeTeX{}).
% \item Standardisation of \verb*|\csname\endcsname | to |\csname\endcsname|
% (the former is formally correct, but the latter was produced for many
% years due to a \TeX{} bug).
% \item Conversion of \texttt{on line \meta{number}} to \texttt{on line ...}
% to allow flexibility in changes to test files.
% \item Conversion of register numbers in assignment lines
% \texttt{\cs{\meta{register}}=\cs{\meta{type}}\meta{number}} to
% \texttt{\cs{\meta{type}}\meta{...}}
% \item Conversion of box numbers in |\show| lines
% \texttt{>~\cs{box}\meta{number}=} to \texttt{>~\cs{box}...=}
% \end{itemize}
%
% \LuaTeX{} makes several additional changes to the log file. As normalising
% these may not be desirable in all cases, they are handled separately.
% When creating \LuaTeX{}-specific test files (either with \LuaTeX{} as
% the standard engine or saving a \LuaTeX{}-specific |.tlg| file) no further
% normalisation is undertaken. On the other hand, for cross-engine comparison
% the following normalisation is applied:
% \begin{itemize}
% \item Removal of additional (unused) |\discretionary| points.
% \item Normalisation of some |\discretionary| data to a \TeX{}90 form.
% \item Removal of |U+...| notation for missing characters.
% \item Removal of |display| for display math boxes
% (included by \TeX90/\pdfTeX{}/\XeTeX).
% \item Removal of Omega-like |direction TLT| information.
% \item Removal of additional whatsit containing local paragraph information
% (|\localinterlinepenalty|, \emph{etc.}).
% \item Rounding of glue set to four decimal places (glue set may be
% slightly different in \LuaTeX{} compared to other engines).
% \item Conversion of low chars ($0$ to $31$) to |^^| notation.
% \end{itemize}
%
% When making comparisons between 8-bit and Unicode engines it is useful to
% format the top half of the 8-bit range such that it appears in the log as
% |^^|\texttt{\meta{char}} (the exact nature of the 8-bit output is otherwise
% dependent on the active code page). This may be controlled using the
% |asciiengines| option. Any engines named here will use a |.tcx| file to
% produce only ASCII chars in the log output, whilst for other engines
% normalisation is carried out from UTF-8 to ASCII. If the option is set to
% an empty table the latter process is skipped: suitable for cases where only
% Unicode engines are in use.
%
% \section{Writing test files}
% \label{sec:writing-tests}
%
% Test files are written in a \TeX{} dialect using the support file |regression-test.tex|, which should be |\input| at the very beginning of each test.
% Additional customisations to this driver can be included in a local |regression-test.cfg| file, which will be loaded automatically if found.
%
% The macros loaded by |regression-test.tex| set up the test system and provide a number of commands to aid the production of a structured test suite.
% The basis of the test suite is to output material into the |.log| file, from which a normalised test output (|.tlg|) file is produced by the build command |save|.
% A number of commands are provided for this; they are all written in uppercase to help avoid possible conflicts with other package commands.
%
% \subsection{Metadata and structural commands}
%
% Any commands that write content to the |.log| file that should be ignored can be surrounded by |\OMIT| \dots\ |\TIMO|.
% At the appropriate location in the document where the |.log| comparisons should start (say, after |\begin{document}|), the test suite must contain the |\START| macro.
% The test should then include \cs{AUTHOR}\marg{authors details} in case a test file fails in the future and needs to be re-analysed.
%
% Some additional diagnostic information can then be included as metadata for the conditions of the test.
% The desired format can be indicated with \cs{FORMAT}\marg{format name}, and any packages or classes loaded can be indicated with
%
% \noindent\hspace*{2\parindent} \cs{CLASS}\oarg{options}\marg{class name, version}\par
% \noindent\hspace*{2\parindent} \cs{PACKAGE}\oarg{options}\marg{package name, version}
%
% \noindent These do not provide information that is useful for automated checking; after all, packages change their version numbers frequently.
% Rather, including this information in a test indicates the conditions under which the test was definitely known to pass at a certain time in the past.
%
% The |\END| command signals the end of the test (but read on).
% Some additional diagnostic information is printed at this time to debug if the test did not complete `properly' in terms of mismatched brace groups or \cs{if}\dots\cs{fi} groups.
%
% In a \LaTeX{} document, |\end{document}| will implicitly call |\END| at the very end of the compilation process.
% If |\END| is used directly (replacing |\end{document}| in the test), the compilation will halt almost immediately, and various tasks that |\end{document}| usually performs will not occur (such as potentially writing to the various |.toc| files, and so on). This can be an advantage if there is additional material printed to the log file in this stage that you wish to ignore, but it is a disadvantage if the test relies on various auxiliary data for a subsequent typesetting run.
% (See the \var{checkruns} variable for how these tests would be test up.)
%
% \subsection{Commands to help write tests}
%
% A simple command \cs{CHECKCOMMAND}\cs{\meta{macro}} is provided to check whether a particular \cs{\meta{macro}} is defined, undefined, or equivalent to \cs{relax}.
% This is useful to flag either that internal macros are remaining local to their definitions, or that defined commands definitely are defined, or even as a reminder that commands you intend to define in a future package need to be tested once they appear.
%
% \cs{TYPE} is used to write material to the \texttt{.log} file, like \LaTeX's \cs{typeout}, but it allows `long' input.
% The following commands are defined to use \cs{TYPE} to output strings to the \texttt{.log} file.
% \begin{itemize}
% \item
% \cs{SEPARATOR} inserts a long line of \texttt{=} symbols to break up the log output.
% \item
% \cs{NEWLINE} inserts a linebreak into the log file.
% \item
% \cs{TRUE}, \cs{FALSE}, \cs{YES}, \cs{NO} output those strings to the log file.
% \item
% \cs{ERROR} is \emph{not} defined but is commonly used to indicate a code path that should never be reached.
% \item
% The \cs{TEST}\marg{title}\marg{contents} command surrounds its \meta{contents} with some \cs{SEPARATOR}s and a \meta{title}.
% \item
% \cs{TESTEXP} surrounds its contents with \cs{TYPE} and formatting to match \cs{TEST}; this can be used as a shorthand to test expandable commands.
% \item
% TODO: would a \cs{TESTFEXP} command (based on \cs{romannumeral} expansion) be useful as well?
% \item
% \cs{BEGINTEST}\marg{title} \dots \cs{ENDTEST} is an environment form of
% \cs{TEST}, allowing verbatim material, \emph{etc.} to appear.
% \end{itemize}
% An example of some of these commands is shown following.
% \begin{Verbatim}
% \TEST{bool_set,~lazy~evaluation}
% {
% \bool_set:Nn \l_tmpa_bool
% {
% \int_compare_p:nNn 1=1
% && \bool_lazy_any_p:n
% {
% { \int_compare_p:nNn 2=3 }
% { \int_compare_p:nNn 4=4 }
% { \int_compare_p:nNn 1=\ERROR } % is skipped
% }
% && \int_compare_p:nNn 2=2
% }
% \bool_if:NTF \l_tmpa_bool \TRUE \FALSE
% }
% \end{Verbatim}
% This test will produce the following in the output.
% \begin{Verbatim}
% ==========================================
% TEST 8: bool_set, lazy evaluation
% ==========================================
% TRUE
% ==========================================
% \end{Verbatim}
% (Only if it's the eighth test in the file of course, and assuming \pkg{expl3}
% coding conventions are active.)
%
% \subsection{Showing box content}
%
% The commands introduced above are only useful for checking algorithmic or logical correctness.
% Many packages should be tested based on their typeset output instead; \TeX{} provides a mechanism for this by printing the contents of a box to the log file.
% The |regression-test.tex| driver file sets up the relevant \TeX{} parameters to produce as much output as possible when showing box output.
%
% A plain \TeX{} example of showing box content follows.
% \begin{Verbatim}[frame=single,fontsize=\small]
% \input regression-test.tex\relax
% \START
% \setbox0=\hbox{\rm hello \it world $a=b+c$}
% \showbox0
% \END
% \end{Verbatim}
% This produces the output shown in Figure~\ref{fig:box-log} (left side).
% It is clear that if the definitions used to typeset the material in the box changes, the log output will differ and the test will no longer pass.
%
% The equivalent test in \LaTeXe{} using \pkg{expl3} is similar.
% \begin{Verbatim}[frame=single,fontsize=\small]
% \input{regression-test.tex}
% \documentclass{article}
% \usepackage{expl3}
% \START
% \ExplSyntaxOn
% \box_new:N \l_tmp_box
% \hbox_set:Nn \l_tmp_box {hello~ \emph{world}~ $a=b+c$}
% \box_show:N \l_tmp_box
% \ExplSyntaxOff
% \END
% \end{Verbatim}
% The output from this test is shown in Figure~\ref{fig:box-log} (right side).
% There is marginal difference (mostly related to font selection and different logging settings in \LaTeX) between the plain and \pkg{expl3} versions.
%
% When examples are not self-contained enough to be typeset into boxes, it is possible to ask \TeX{} to output the entire contents of a page.
% Insert \cs{showoutput} for \LaTeX{} or set \cs{tracingoutput} positive for plain \TeX{}; ensure that the test ends with \cs{newpage} or equivalent because \TeX{} waits until the entire page is finished before outputting it.
%
% TODO: should we add something like \cs{TRACEPAGES} to be format-agnostic here? Should this perhaps even be active by default?
%
% \begin{figure}
% \hspace*{-3cm}
% \begin{BVerbatim}[fontsize=\small]
% > \box0=
% \hbox(6.94444+0.83333)x90.56589
% .\tenrm h
% .\tenrm e
% .\tenrm l
% .\tenrm l
% .\tenrm o
% .\glue 3.33333 plus 1.66666 minus 1.11111
% .\tenit w
% .\tenit o
% .\tenit r
% .\tenit l
% .\tenit d
%
% .\glue 3.57774 plus 1.53333 minus 1.0222
% .\mathon
% .\teni a
% .\glue(\thickmuskip) 2.77771 plus 2.77771
% .\tenrm =
% .\glue(\thickmuskip) 2.77771 plus 2.77771
% .\teni b
% .\glue(\medmuskip) 2.22217 plus 1.11108 minus 2.22217
% .\tenrm +
% .\glue(\medmuskip) 2.22217 plus 1.11108 minus 2.22217
% .\teni c
% .\mathoff
%
% ! OK.
% l.9 \showbox0
%
%
% \end{BVerbatim}
% \qquad
% \begin{BVerbatim}[fontsize=\small]
% > \box71=
% \hbox(6.94444+0.83333)x91.35481
% .\OT1/cmr/m/n/10 h
% .\OT1/cmr/m/n/10 e
% .\OT1/cmr/m/n/10 l
% .\OT1/cmr/m/n/10 l
% .\OT1/cmr/m/n/10 o
% .\glue 3.33333 plus 1.66666 minus 1.11111
% .\OT1/cmr/m/it/10 w
% .\OT1/cmr/m/it/10 o
% .\OT1/cmr/m/it/10 r
% .\OT1/cmr/m/it/10 l
% .\OT1/cmr/m/it/10 d
% .\kern 1.03334
% .\glue 3.33333 plus 1.66666 minus 1.11111
% .\mathon
% .\OML/cmm/m/it/10 a
% .\glue(\thickmuskip) 2.77771 plus 2.77771
% .\OT1/cmr/m/n/10 =
% .\glue(\thickmuskip) 2.77771 plus 2.77771
% .\OML/cmm/m/it/10 b
% .\glue(\medmuskip) 2.22217 plus 1.11108 minus 2.22217
% .\OT1/cmr/m/n/10 +
% .\glue(\medmuskip) 2.22217 plus 1.11108 minus 2.22217
% .\OML/cmm/m/it/10 c
% .\mathoff
%
% ! OK.
% <argument> \l_tmp_box
%
% l.12 \box_show:N \l_tmp_box
% \end{BVerbatim}
% \caption{Output from displaying the contents of a simple box to the log file, using plain \TeX{} (left) and \pkg{expl3} (right). Some blank lines have been added to the plain \TeX{} version to help with the comparison.}
% \label{fig:box-log}
% \end{figure}
%
% \subsection{Testing entire pages}
%
% There may be occasions where creating entire test pages is necessary
% to observe the test output required. That is best achieved by applying
% \cs{showoutput} and forcing a complete page to be produced, for example
% \begin{Verbatim}[frame=single,fontsize=\small]
% \input{regression-test.tex}
% \documentclass{article}
% \usepackage{expl3}
% \START
% \showoutput
% % Test content here
% \vfil\break
% \END
% \end{Verbatim}
%
% \subsection{Additional test tasks}
%
% A standard test will run the file \texttt{\meta{name}.lvt} using one
% or more engines, but will not carry out any additional processing. For
% some tests, for example bibliography generation, it may be desirable to
% call one or more tools in addition to the engine. This can be arranged
% by defining |runtest_tasks|, a function taking one argument, the name
% of the current test (this is equivalent to \TeX{}'s \cs{jobname},
% \emph{i.e.}~it lacks an extension). The function |runtest_tasks|
% is is into a call to the system to run the engine. As such, it
% should take return a string with the appropriate command(s)
% and option(s). If more than one task is required, these should be separated
% by use of |os_concat|, a string variable defined by \pkg{l3build} as the
% correct concatenation marker for the system. An example of |runtest_tasks|
% suitable for calling Biber is shown in Listing~\ref{fig:test-tasks}.
% \begin{figure}
% \begin{lstlisting}[frame=single,language={[5.2]Lua},gobble = 6]
% function runtest_tasks(name)
% return "biber " .. name
% end
% \end{lstlisting}
% \caption{Example \texttt{runtest_tasks} function.}
% \label{fig:test-tasks}
% \end{figure}
%
% \subsection{Epoch setting}
%
% To produce predictable output when suing dates, the test system offers the