\input regression-test.tex
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{tikzphysics.fluids,tikzphysics.elements}
\newdimen\fluidtestactual
\newdimen\fluidtesterror
\newcommand{\fluidassert}[3]{%
  \fluidtesterror=#1\relax\advance\fluidtesterror by -#2\relax
  \ifdim\fluidtesterror<0pt \fluidtesterror=-\fluidtesterror\fi
  \ifdim\fluidtesterror<.03pt\TYPE{PASS: #3}\else\TYPE{FAIL: #3}\fi}
\newcommand{\fluidx}[3]{\pgfextractx{\fluidtestactual}{\pgfpointanchor{#1}{center}}\fluidassert{\fluidtestactual}{#2}{#3}}
\newcommand{\fluidy}[3]{\pgfextracty{\fluidtestactual}{\pgfpointanchor{#1}{center}}\fluidassert{\fluidtestactual}{#2}{#3}}
\begin{document}
\START
\setbox0=\hbox{\begin{tikzpicture}
\pic (T) {fluid tank diagram={fluid={width=4cm,height=2cm,left level=.8,right level=.4},fill=blue!20}};
\fluidx{T-right-surface}{4cm}{scoped width}
\fluidy{T-left-surface}{1.6cm}{left surface fraction}
\fluidy{T-surface}{1.2cm}{surface midpoint}
\pic (A) {physics fluid tank={physics fluid width=40mm,physics fluid height=20mm,physics fluid left level=.8}};
\fluidx{A-right}{4cm}{collision safe pic and key aliases}
\pic (D) {physics fluid tank diagram={physics fluid width=40mm,physics fluid height=20mm}};
\fluidx{D-right}{4cm}{explicit collision safe diagram alias}
\pic (B) {fluid tank diagram};
\fluidx{B-right}{3cm}{geometry does not leak}
\pic[rotate=90,scale=2] (R) {fluid tank diagram={fluid width=2cm,fluid height=1cm}};
\fluidx{R-right}{-1cm}{rotated scaled x coordinate}
\fluidy{R-right}{4cm}{rotated scaled y coordinate}
\pic (U) {u tube diagram={fluid left level=.4,fluid right level=.7,fluid level=.9}};
\fluidy{U-interface}{1.6cm}{two fluid interface}
\fluidy{U-upper-surface}{3.6cm}{upper fluid surface}
\pic (V) {rotating fluid diagram={fluid height=4cm,fluid level=.4,fluid bend=.3}};
\fluidy{V-vertex}{1.6cm}{parabola vertex}
\fluidy{V-rim-surface}{2.8cm}{parabola rim}
\pic (M) {meniscus diagram={fluid height=4cm,fluid level=.6,fluid bend=-.2}};
\fluidy{M-surface}{3cm}{convex meniscus midpoint}
\pic (H) {hydraulic press};
\fluidx{H-large-piston}{.64cm}{large piston centre}
\fluidx{H-small-piston}{3.85cm}{small piston centre}
\node[minimum width=2cm,minimum height=1cm,inner sep=0pt,outer sep=0pt] (N) at (0,0) {};
\pgfextractx{\fluidtestactual}{\pgfpointanchor{N}{east}}\fluidassert{\fluidtestactual}{1cm}{native minimum width unchanged}
\end{tikzpicture}}
\makeatletter
\tikzset{every element label/.append style={execute at begin node={\fluidassert{\f@size pt}{14.4pt}{individual element label font}}}}
\setbox0=\hbox{\begin{tikzpicture}
\node[rectangular element,font=\Large,show dimensions] {};
\end{tikzpicture}}
\tikzset{every fluid label/.append style={execute at begin node={\fluidassert{\f@size pt}{12pt}{native fluid picture font}}}}
\setbox0=\hbox{\begin{tikzpicture}[font=\large]
\pic {pressure element diagram};
\end{tikzpicture}}
\makeatother

\setbox0=\hbox{\begin{tikzpicture}
\node[fluid tank,outer sep=0pt,fluid width=4cm,fluid height=2cm,
 fluid left level=.8,fluid right level=.4,pattern=north east lines] (T) {};
\pgfextractx{\fluidtestactual}{\pgfpointanchor{T}{east}}\fluidassert{\fluidtestactual}{2cm}{native node east anchor}
\pgfextracty{\fluidtestactual}{\pgfpointanchor{T}{left-surface}}\fluidassert{\fluidtestactual}{.6cm}{native node surface anchor}
\node[fluid tank,anchor=west,outer sep=0pt,minimum width=5cm] (W) at (T.east) {};
\pgfextractx{\fluidtestactual}{\pgfpointanchor{W}{east}}\fluidassert{\fluidtestactual}{7cm}{native minimum width and anchor placement}
\node[fluid tank,outer sep=0pt,rotate=90] (R) {};
\pgfextractx{\fluidtestactual}{\pgfpointanchor{R}{north}}\fluidassert{\fluidtestactual}{-1.5cm}{native node rotation}
\node[rectangle,draw,fill=red,minimum width=1cm] (plain) at (0,-5) {plain};
\makeatletter
\node[fluid tank,fill=cyan!20] (solid) {};
\csname pgf@sh@ma@solid\endcsname\tikzphysics@fluid@nodestate
\def\expected{none}\ifx\expected\tikzphysics@fluid@nodepattern\TYPE{PASS: native fill overrides default pattern}\else\TYPE{FAIL: solid fill}\fi
\node[fluid tank,pattern=horizontal lines,pattern color=blue] (patterned) {};
\csname pgf@sh@ma@patterned\endcsname\tikzphysics@fluid@nodestate
\def\expected{horizontal lines}\ifx\expected\tikzphysics@fluid@nodepattern\TYPE{PASS: native pattern override}\else\TYPE{FAIL: pattern override}\fi
\def\expected{blue}\ifx\expected\tikz@pattern@color\TYPE{PASS: native pattern color}\else\TYPE{FAIL: pattern color}\fi
\makeatother
\end{tikzpicture}}
\END
\end{document}