Merge pull request #222 from tarnfeld/empty-ssl-consistency

SSL consistency renderer cannot call max() with no arguments

ripe/atlas/tools/renderers/ssl_consistency.py

@@ -64,6 +64,8 @@ def get_nprobes_ofpopular_cert(self):
         Gets the number of probes that have seen the most popular
         (in terms of probes) cert.
         """
+        if not self.uniqcerts:
+            return 0
         return max(
             [self.uniqcerts[cert_id]["cnt"] for cert_id in self.uniqcerts]
         )

tests/renderers/ssl_consistency.py

@@ -189,6 +189,18 @@ def test_get_nprobes_ofpopular_cert(self):
             renderer.gather_unique_certs(sagans)
             self.assertEquals(renderer.get_nprobes_ofpopular_cert(), 11)
 
+    def test_get_nprobes_ofpopular_cert_empty(self):
+        """Tests that getting the number of probes for popular certs does not
+        throw an error when there are no valid certificates."""
+
+        path = 'ripe.atlas.tools.helpers.rendering.Probe.get_many'
+        with mock.patch(path) as mock_get_many:
+            mock_get_many.return_value = self.probes.values()
+            sagans = SaganSet([])
+            renderer = Renderer()
+            renderer.gather_unique_certs(sagans)
+            self.assertEquals(renderer.get_nprobes_ofpopular_cert(), 0)
+
     def test_render_certificate(self):
         """Tests rendering of single certificate."""
         expected_output = (