Visual regression test

Project.toml

@@ -40,6 +40,8 @@ OffsetArrays = "6fe1bfb0-de20-5000-8ca7-80f57d26f881"
 SymEngine = "123dc426-2d89-5057-bbad-38513e3affd8"
 SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+VisualRegressionTests = "34922c18-7c2a-561c-bac1-01e79b2c4c92"
+Gtk = "4c0ca9eb-093a-5379-98c5-f87ac0bbbf44"
 
 [targets]
-test = ["DataFrames", "OffsetArrays", "SymEngine", "SparseArrays", "Test"]
+test = ["DataFrames", "OffsetArrays", "SymEngine", "SparseArrays", "VisualRegressionTests", "Gtk", "Test"]

src/utils.jl

@@ -145,6 +145,7 @@ function render(s::LaTeXString, mime::MIME"image/png";
  callshow=true,
  open=true,
  dpi=DEFAULT_DPI[],
+ transparent=true,
  kw...
  )
  ext = "png"
@@ -154,11 +155,13 @@ function render(s::LaTeXString, mime::MIME"image/png";
  # prefer tex -> pdf -> png instead
  if convert === :gs
  aux_mime = MIME("application/pdf")
- cmd = `gs -sDEVICE=pngalpha -dTextAlphaBits=4 -r$dpi -o $name.$ext $aux_name.pdf`
+ device = transparent ? "pngalpha" : "png16m"
+ cmd = `gs -sDEVICE=$device -dTextAlphaBits=4 -r$dpi -o $name.$ext $aux_name.pdf`
  elseif convert === :dvipng
  aux_mime = MIME("application/x-dvi")
+ background = transparent ? "Transparent" : "white"
  deb = debug ? [] : ["-q"]
- cmd = `dvipng $(deb...) -bg Transparent -D $dpi -T tight $aux_name.dvi -o $name.$ext`
+ cmd = `dvipng $(deb...) -bg $background -D $dpi -T tight $aux_name.dvi -o $name.$ext`
  else
  error("$convert program not understood")
  end

test/runtests.jl

@@ -6,7 +6,9 @@ using LaTeXStrings
 using Test
 
 # Run tests
-
+if Sys.MACHINE == "x86_64-linux-gnu"
+ @testset "visual regression tests" begin include("visualregression_tests.jl") end
+end
 @testset "macro test" begin include("macros.jl") end
 @testset "recipe test" begin include("recipe_test.jl") end
 @testset "latexify tests" begin include("latexify_test.jl") end

test/visualregression_tests.jl

@@ -0,0 +1,9 @@
+using Latexify, VisualRegressionTests, Gtk
+
+function latexify_VRT(filename, args...; kwargs...)
+ testfun(fname) = render(latexify(args...; kwargs...), MIME"image/png"(); name=replace(fname, r".png$"=>""), transparent=false)
+ @visualtest testfun joinpath("visualreferences", filename)
+end
+
+latexify_VRT("simpleequation.png", :(x^2-2y_a*exp(3)∈[1,2,3]); cdot=false)
+