%% test-errors.tex
%% ===============
%% The error messages of algorithmlite.
%%
%%   pdflatex -jobname=test-errors-algbefore "\def\CASE{algbefore}%
%%     \input test-errors"
%%
%% \CASE is one of
%%   algbefore  the algorithm package before algorithmlite;
%%   algafter   the algorithm package after algorithmlite;
%%   alg2e      the algorithm2e package before algorithmlite;
%%   alg2eafter the algorithm2e package after algorithmlite;
%%   defined    the counter algorithm defined before algorithmlite.
%%
%% What to check:
%%   * the error message given in the Makefile.
\ifdefined\CASE\else\def\CASE{algbefore}\fi
\def\ALGLcase#1{\def\ALGLtmp{#1}\ifx\ALGLtmp\CASE}
\documentclass{article}
\makeatletter
\ALGLcase{algbefore}\usepackage{algorithm}\fi
\ALGLcase{alg2e}\usepackage{algorithm2e}\fi
\ALGLcase{defined}\newcounter{algorithm}\fi
\usepackage{algorithmlite}
\ALGLcase{algafter}\usepackage{algorithm}\fi
\ALGLcase{alg2eafter}\usepackage{algorithm2e}\fi
\makeatother
\begin{document}
Text.
\end{document}