def test_empty(self):
"""
If passed an empty input file, L{filter} writes a I{pre} tag containing
only an end marker to the output file.
"""
input = StringIO("")
output = StringIO()
filter(input, output)
self.assertEqual(output.getvalue(), '<pre><span class="py-src-endmarker"></span></pre>\n')
def test_variable(self):
"""
If passed an input file containing a variable access, L{filter} writes
a I{pre} tag containing a I{py-src-variable} span containing the
variable.
"""
input = StringIO("foo\n")
output = StringIO()
filter(input, output)
self.assertEqual(
output.getvalue(),
'<pre><span class="py-src-variable">foo</span><span class="py-src-newline">\n'
'</span><span class="py-src-endmarker"></span></pre>\n')