I broke up with neovim....vim is my best friend now

dot_vim/plugged/vimtex/test/test-compiler-pdfmode/test-conflict-warning/Makefile

@@ -0,0 +1,9 @@
+.PHONY: test
+
+MYVIM ?= nvim --clean --headless
+
+INMAKE := 1
+export INMAKE
+
+test:
+	@$(MYVIM) -u test.vim

dot_vim/plugged/vimtex/test/test-compiler-pdfmode/test-conflict-warning/latexmkrc

@@ -0,0 +1,3 @@
+$pdf_mode = 4;  # compile with lualatex
+
+# vim: ft=perl

dot_vim/plugged/vimtex/test/test-compiler-pdfmode/test-conflict-warning/main.tex

@@ -0,0 +1,9 @@
+% The following TeX program directive is not consistent with the value of
+% $pdf_mode in latexmkrc, therefore a warning message is expected.
+
+%! TEX program = xelatex
+
+\documentclass{minimal}
+\begin{document}
+Hello world!
+\end{document}

dot_vim/plugged/vimtex/test/test-compiler-pdfmode/test-conflict-warning/test.vim

@@ -0,0 +1,23 @@
+set nocompatible
+let &rtp = '../../..,' . &rtp
+filetype plugin on
+
+nnoremap q :qall!<cr>
+
+call vimtex#log#set_silent()
+
+if empty($INMAKE)
+  edit main.tex
+  finish
+else
+  silent edit main.tex
+endif
+
+" Get engine
+let s:engine = b:vimtex.compiler.get_engine()
+
+let s:warnings = vimtex#log#get()
+call assert_equal(len(s:warnings), 1)
+call assert_match('pdf_mode.*inconsistent', join(s:warnings[0].msg))
+
+call vimtex#test#finished()