Merge pull request #299 from gustaphe/renderlog

Informative error messages for failed renders

src/Latexify.jl

@@ -13,6 +13,7 @@ using Markdown
 using MacroTools: postwalk
 import MacroTools
 using Format
+import Base.showerror
 
 export latexify, md, copy_to_clipboard, auto_display, set_default, get_default,
     reset_default, @latexrecipe, render, @latexify, @latexrun, @latexdefine

src/utils.jl

@@ -36,11 +36,18 @@ function _compile(s::LaTeXString, cmd::Cmd, ext::String;
         open=true,
         kw...
     )
+    name = abspath(name)
     mktempdir() do source_dir
         cd(source_dir) do
             _writetex(s; name="main", kw...)
             debug || (cmd = pipeline(cmd, devnull))
-            run(cmd)
+            try
+                run(cmd)
+            catch err
+                isa(err, ProcessFailedException) || rethrow(err)
+                mv("$source_dir/main.log", "$name.log"; force=true)
+                rethrow(LatexifyRenderError("$name.log"))
+            end
         end
         mv("$source_dir/main.$ext", "$name.$ext"; force=true)
     end
@@ -226,3 +233,23 @@ end
 
 _packagename(x::AbstractString) = "{$x}"
 _packagename(x::Tuple) = "[$(join(x[2:end], ", "))]{$(first(x))}"
+
+struct LatexifyRenderError <: Exception
+    logfilename::String
+end
+function Base.showerror(io::IO, e::LatexifyRenderError)
+    isfile(e.logfilename) || return println(io, "an error occured while rendering LaTeX, no log file available.")
+    println(io, "an error occured while rendering LaTeX: ")
+    secondline = false
+    for l = eachline(e.logfilename)
+        if secondline
+            println(io, "\t", l)
+            break;
+        end
+        m = match(r"^! (.*)$", l)
+        isnothing(m) && continue
+        println(io, "\t", m[1])
+        secondline = true
+    end
+    println(io, "Check the log file at ", e.logfilename, " for more information")
+end

test/utils_test.jl

@@ -74,3 +74,29 @@ tex = read(filename, String)
 
 @test occursin("MathJax", Latexify.html_wrap(latexify(:(sin(α)))))
 @test Latexify.best_displayable() isa MIME
+
+#@test_throws Latexify.LatexifyRenderError render(L"x^2^3") # Does not run on Windows and Mac CI
+logfile = tempname()
+open(logfile, "w") do io
+    println(io, raw"""
+            This is LuaHBTeX, Version 1.18.0 (TeX Live 2024/Arch Linux)  (format=lualatex 2024.4.3)  7 AUG 2024 14:19
+            restricted system commands enabled.
+            ** Skipping many files **
+            LaTeX Font Info:    Trying to load font information for U+msb on input line 5.
+            (/usr/share/texmf-dist/tex/latex/amsfonts/umsb.fd
+            File: umsb.fd 2013/01/14 v3.01 AMS symbols B
+            )
+            ! Double superscript.
+            l.8     $x^2^
+            3$
+            I treat `x^1^2' essentially like `x^1{}^2'.
+            ** More lines skipped **
+            """)
+end
+e = Latexify.LatexifyRenderError(logfile)
+@test sprint(showerror, e) == """
+an error occured while rendering LaTeX: \n\tDouble superscript.
+\tl.8     \$x^2^
+Check the log file at $logfile for more information
+"""
+