style: add Styles.__len__()

Steve Canny · Steve Canny · commit bb948db06f0d · 2015-02-08T00:00:31.000-08:00
diff --git a/docx/styles/styles.py b/docx/styles/styles.py
@@ -19,3 +19,6 @@ class Styles(ElementProxy):
     """
 
     __slots__ = ()
+
+    def __len__(self):
+        return len(self._element.style_lst)
diff --git a/tests/styles/__init__.py b/tests/styles/__init__.py
diff --git a/tests/styles/test_styles.py b/tests/styles/test_styles.py
@@ -0,0 +1,35 @@
+# encoding: utf-8
+
+"""
+Test suite for the docx.styles module
+"""
+
+from __future__ import (
+    absolute_import, division, print_function, unicode_literals
+)
+
+import pytest
+
+from docx.styles.styles import Styles
+
+from ..unitutil.cxml import element
+
+
+class DescribeStyles(object):
+
+    def it_knows_its_length(self, len_fixture):
+        styles, expected_value = len_fixture
+        assert len(styles) == expected_value
+
+    # fixture --------------------------------------------------------
+
+    @pytest.fixture(params=[
+        ('w:styles',                           0),
+        ('w:styles/w:style',                   1),
+        ('w:styles/(w:style,w:style)',         2),
+        ('w:styles/(w:style,w:style,w:style)', 3),
+    ])
+    def len_fixture(self, request):
+        styles_cxml, expected_value = request.param
+        styles = Styles(element(styles_cxml))
+        return styles, expected_value
