\input regression-test.tex
\documentclass{article}
\usepackage[columnsep=2.5mm]{kanban-board}
\begin{document}
\sbox0{\scriptsize $x$}% Load math font sizes outside captured output.
\START
\makeatletter
\ifdim\kanban@columnsep=2.5mm\relax
  \TYPE{KANBAN PACKAGE COLUMNSEP OK}
\else
  \TYPE{KANBAN PACKAGE COLUMNSEP FAILED}
\fi
\newcommand\kbexpectaccepted[2]{%
  \kanban@validatedimensionTF{#1}
    {\TYPE{#2 OK}}
    {\TYPE{#2 FAILED}}}
\newcommand\kbexpectrejected[2]{%
  \kanban@validatedimensionTF{#1}
    {\TYPE{#2 FAILED}}
    {\TYPE{#2 OK}}}
\newlength\kbtestlength
\def\kbtestgap{2mm}
\let\kbtestindent\parindent
\kbexpectaccepted{2mm}{KANBAN EXPLICIT DIMENSION ACCEPTED}
\kbexpectaccepted{2 mm}{KANBAN SPACED UNIT ACCEPTED}
\kbexpectaccepted{2truemm}{KANBAN TRUE UNIT ACCEPTED}
\kbexpectaccepted{2 true mm}{KANBAN SPACED TRUE UNIT ACCEPTED}
\kbexpectaccepted{.5em}{KANBAN FONT UNIT ACCEPTED}
\kbexpectaccepted{\parindent}{KANBAN DIMENSION PARAMETER ACCEPTED}
\kbexpectaccepted{\hsize}{KANBAN HSIZE PARAMETER ACCEPTED}
\kbexpectaccepted{\baselineskip}{KANBAN GLUE PARAMETER ACCEPTED}
\kbexpectaccepted{\parskip}{KANBAN PARSKIP PARAMETER ACCEPTED}
\kbexpectaccepted{\kbtestindent}{KANBAN LET COPY OF PARAMETER ACCEPTED}
\kbexpectaccepted{\linewidth}{KANBAN DIMENSION REGISTER ACCEPTED}
\kbexpectaccepted{\kbtestlength}{KANBAN SKIP REGISTER ACCEPTED}
\kbexpectaccepted{\kbtestgap}{KANBAN MACRO DIMENSION ACCEPTED}
\kbexpectrejected{\dimexpr 2mm\relax}{KANBAN DIMEXPR REJECTED}
\kbexpectrejected{0.5\linewidth}{KANBAN SCALED REGISTER REJECTED}
\kbexpectrejected{2}{KANBAN MISSING UNIT REJECTED}
\kbexpectrejected{mm}{KANBAN MISSING NUMBER REJECTED}
\kbexpectrejected{2trueem}{KANBAN TRUE FONT UNIT REJECTED}
\kbexpectrejected{\thinmuskip}{KANBAN MATH GLUE PARAMETER REJECTED}
\kbexpectrejected{\relax}{KANBAN RELAX REJECTED}
\kbexpectrejected{\emph{2mm}}{KANBAN ROBUST COMMAND REJECTED}
\kbexpectrejected{not-a-length}{KANBAN TEXT REJECTED}
\makeatother
\begin{kanban}[columns={One,Two},columnsep=\parindent]
  \makeatletter
  \ifdim\kanban@boardcolumnsep=\parindent
    \TYPE{KANBAN PARAMETER GAP ASSIGNED OK}
  \else
    \TYPE{KANBAN PARAMETER GAP ASSIGNED FAILED}
  \fi
  \makeatother
  \kanbantask{One}{Exercise a TeX parameter as the gap}
\end{kanban}
\kbset{columnsep=2 true mm}
\makeatletter
\ifdim\kanban@columnsep=2truemm\relax
  \TYPE{KANBAN TRUE UNIT GAP ASSIGNED OK}
\else
  \TYPE{KANBAN TRUE UNIT GAP ASSIGNED FAILED}
\fi
\makeatother
\begin{kanban}[columns={A deliberately long column heading,Done,Empty}]
  \kanbantask{A deliberately long column heading}
    {Check the package option and wrapped heading height}
  \kanbantask[completed]{Done}{Check the equal body height}
\end{kanban}
\END
\end{document}