test: add minimal example for markdown

refer: #2874, #2978

.gitignore

@@ -4,3 +4,7 @@ test/test-compiler/latexrun
 test/test-syntax/syntax/
 test/test-textobj-targets/targets.vim/
 test/issues
+test/test-completion-bibtex/test_parser_*
+test/test-quickfix-fix-path/test_hbox*
+
+*.log

test/example-markdown/after/syntax/markdown.vim

@@ -0,0 +1,12 @@
+if exists('b:_loaded_markdown_vimtex')
+  finish
+endif
+let b:_loaded_markdown_vimtex = 1
+
+unlet b:current_syntax
+syntax include @tex syntax/tex.vim
+let b:current_syntax = 'markdown'
+
+syntax region mkdMath start="\\\@<!\$" end="\$" skip="\\\$" contains=@tex keepend
+syntax region mkdMath start="\\\@<!\$\$" end="\$\$" skip="\\\$" contains=@tex keepend
+syntax region mkdMath start="\\\@<!\\(" end="\\\@<!\\)" contains=@tex keepend

test/example-markdown/syntax/markdown.vim

@@ -0,0 +1,16 @@
+if exists('b:_loaded_markdown_vimtex')
+  finish
+endif
+let b:_loaded_markdown_vimtex = 1
+
+if !exists('b:current_syntax')
+  runtime! syntax/markdown.vim
+endif
+
+unlet! b:current_syntax
+syntax include @tex syntax/tex.vim
+let b:current_syntax = 'markdown'
+
+syntax region mkdMath start="\\\@<!\$" end="\$" skip="\\\$" contains=@tex keepend
+syntax region mkdMath start="\\\@<!\$\$" end="\$\$" skip="\\\$" contains=@tex keepend
+syntax region mkdMath start="\\\@<!\\(" end="\\\@<!\\)" contains=@tex keepend

test/example-markdown/test.lua

@@ -0,0 +1,31 @@
+vim.opt.runtimepath:prepend "~/.local/plugged/vimtex"
+vim.opt.runtimepath:append "~/.local/plugged/vimtex/after"
+-- vim.opt.runtimepath:prepend "."
+vim.opt.runtimepath:append "./after"
+
+vim.cmd [[filetype plugin indent on]]
+vim.cmd [[syntax enable]]
+
+vim.keymap.set("n", "q", "<cmd>qall!<cr>")
+
+vim.g.vimtex_cache_root = "."
+vim.g.vimtex_cache_persistent = false
+
+vim.cmd.colorscheme "morning"
+
+vim.api.nvim_set_hl(0, "Conceal", { bg = "NONE", fg = "blue" })
+vim.api.nvim_set_hl(0, "texCmdRef", { fg = "cyan" })
+
+local au_group = vim.api.nvim_create_augroup("init", {})
+vim.api.nvim_create_autocmd("CursorMoved", {
+  pattern = "*",
+  group = au_group,
+  command = [[echo join(vimtex#syntax#stack(), ' -> ')]],
+})
+vim.api.nvim_create_autocmd("FileType", {
+  pattern = "markdown",
+  group = au_group,
+  command = [[call vimtex#init()]],
+})
+
+vim.cmd.edit "test.md"

test/example-markdown/test.md

@@ -0,0 +1,7 @@
+# Title
+
+math here $f(x) = 1$
+
+math here \(f(x) = 1\)
+
+**bold text** _italic text_