Add testcase for graphviz

tests/roots/test-ext-graphviz/conf.py

@@ -0,0 +1,4 @@
+# -*- coding: utf-8 -*-
+
+extensions = ['sphinx.ext.graphviz']
+master_doc = 'index'

tests/roots/test-ext-graphviz/index.rst

@@ -0,0 +1,7 @@
+graphviz
+========
+
+.. digraph:: foo
+   :caption: caption of graph
+
+   bar -> baz

tests/test_ext_graphviz.py

@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+"""
+    test_ext_graphviz
+    ~~~~~~~~~~~~~~~~~
+
+    Test sphinx.ext.graphviz extension.
+
+    :copyright: Copyright 2007-2015 by the Sphinx team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+import re
+from util import with_app
+
+
+@with_app('html', testroot='ext-graphviz')
+def test_graphviz(app, status, warning):
+    app.builder.build_all()
+    if "dot command 'dot' cannot be run" not in warning.getvalue():
+        content = (app.outdir / 'index.html').text()
+        html = ('<p class="graphviz">\s*<img .*?/>\s*</p>\s*'
+                '<p class="caption"><span class="caption-text">caption of graph</span>')
+        assert re.search(html, content, re.S)