Rework Latex test for nbconvert Python API

Also, skip it if pandoc is not available

IPython/nbconvert/exporters/tests/test_latex.py

@@ -1,71 +1,101
-"""
-Module with tests for latex.py
-"""
+"""Tests for Latex exporter"""
 
-#-----------------------------------------------------------------------------
-# Copyright (c) 2013, the IPython Development Team.
-#
+# Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
-#
-# The full license is in the file COPYING.txt, distributed with this software.
-#-----------------------------------------------------------------------------
 
-#-----------------------------------------------------------------------------
-# Imports
-#-----------------------------------------------------------------------------
+import os.path
+import textwrap
 
 from .base import ExportersTestsBase
 from ..latex import LatexExporter
+from IPython.nbformat import current
 from IPython.testing.decorators import onlyif_cmds_exist
+from IPython.utils.tempdir import TemporaryDirectory
 
-#-----------------------------------------------------------------------------
-# Class
-#-----------------------------------------------------------------------------
 
 class TestLatexExporter(ExportersTestsBase):
     """Contains test functions for latex.py"""
 
     exporter_class = LatexExporter
     should_include_raw = ['latex']
 
     def test_constructor(self):
         """
         Can a LatexExporter be constructed?
         """
         LatexExporter()
 
 
     @onlyif_cmds_exist('pandoc')
     def test_export(self):
         """
         Can a LatexExporter export something?
         """
         (output, resources) = LatexExporter().from_filename(self._get_notebook())
         assert len(output) > 0
 
 
     @onlyif_cmds_exist('pandoc')
     def test_export_book(self):
         """
         Can a LatexExporter export using 'report' template?
         """
         (output, resources) = LatexExporter(template_file='report').from_filename(self._get_notebook())
         assert len(output) > 0
 
 
     @onlyif_cmds_exist('pandoc')
     def test_export_basic(self):
         """
         Can a LatexExporter export using 'article' template?
         """
         (output, resources) = LatexExporter(template_file='article').from_filename(self._get_notebook())
         assert len(output) > 0
 
 
     @onlyif_cmds_exist('pandoc')
     def test_export_article(self):
         """
         Can a LatexExporter export using 'article' template?
         """
         (output, resources) = LatexExporter(template_file='article').from_filename(self._get_notebook())
         assert len(output) > 0
+
+    @onlyif_cmds_exist('pandoc')
+    def test_very_long_cells(self):
+        """
+        Torture test that long cells do not cause issues
+        """
+        lorem_ipsum_text = textwrap.dedent("""\
+          Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec
+          dignissim, ipsum non facilisis tempus, dui felis tincidunt metus,
+          nec pulvinar neque odio eget risus. Nulla nisi lectus, cursus
+          suscipit interdum at, ultrices sit amet orci. Mauris facilisis
+          imperdiet elit, vitae scelerisque ipsum dignissim non. Integer
+          consequat malesuada neque sit amet pulvinar. Curabitur pretium
+          ut turpis eget aliquet. Maecenas sagittis lacus sed lectus
+          volutpat, eu adipiscing purus pulvinar. Maecenas consequat
+          luctus urna, eget cursus quam mollis a. Aliquam vitae ornare
+          erat, non hendrerit urna. Sed eu diam nec massa egestas pharetra
+          at nec tellus. Fusce feugiat lacus quis urna sollicitudin volutpat.
+          Quisque at sapien non nibh feugiat tempus ac ultricies purus.
+           """)
+        lorem_ipsum_text = lorem_ipsum_text.replace("\n"," ") + "\n\n"
+        large_lorem_ipsum_text = "".join([lorem_ipsum_text]*3000)
+
+        notebook_name = "lorem_ipsum_long.ipynb"
+        nb = current.new_notebook(
+            worksheets=[
+                current.new_worksheet(cells=[
+                    current.new_text_cell('markdown',source=large_lorem_ipsum_text)
+                ])
+            ]
+        )
+
+        with TemporaryDirectory() as td:
+            nbfile = os.path.join(td, notebook_name)
+            with open(nbfile, 'w') as f:
+                current.write(nb, f, 'ipynb')
+
+            (output, resources) = LatexExporter(template_file='article').from_filename(nbfile)            
+            assert len(output) > 0