test latex css (#41)

.flake8

@@ -1,2 +1,4 @@
 [flake8]
 max_line_length = 120
+per-file-ignores =
+    tests/test/test_latex.py:E501

fixture/latex2.md

@@ -0,0 +1,5 @@
+# Title
+
+test some math formula
+
+write some $$\sum_1^n x_n$$

tests/test/test_latex.py

@@ -2,8 +2,14 @@
 
 make test T=test_latex.py
 """
+# pylint: disable=line-too-long
 from . import TestBase
 
+LATEX_CSS = """
+<script type="text/javascript" src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
+<script type="text/x-mathjax-config"> MathJax.Hub.Config({ tex2jax: {inlineMath: [['$', '$']]}, messageStyle: "none" });</script>
+"""
+
 
 class TestLatex(TestBase):
     """Latex content."""
@@ -17,3 +23,14 @@ def test_latex(self):
         html = pdf.add_section(Section(text))
         # print(html)
         assert "$$" in html
+
+    def test_latex_css(self):
+        """Convert latext content to pdf with css."""
+        from markdown_pdf import Section, MarkdownPdf
+
+        pdf = MarkdownPdf()
+        pdf.add_section(
+          Section(open(self.fixture("latex2.md"), "rt", encoding='utf-8').read()),
+          user_css=LATEX_CSS
+        )
+        pdf.save(self.build("latex2.pdf"))