be more forgiving of bad affiliation date ranges

Scan all affiliations and take the latest one that has a start date
that makes it valid for the date in question. This works around the
fact that there is a bug in the web UI for the foundation site making
it difficult for users to modify their existing affiliations.

Change-Id: I369d777e0ef2064fc728f9042d9b0e3eca84d350
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

goal_tools/foundation.py

@@ -104,9 +104,14 @@ class Member:
                 return affiliation
 
     def find_affiliation(self, when):
-        for affiliation in self.affiliations:
-            if affiliation.active(when):
-                return affiliation
+        candidates = [
+            affiliation
+            for affiliation in self.affiliations
+            if affiliation.active(when)
+        ]
+        if candidates:
+            return candidates[-1]
+        return None
 
 
 def lookup_member(email):

goal_tools/tests/test_foundation.py

@@ -95,6 +95,32 @@ class TestFoundationMember(base.TestCase):
             a.organization,
         )
 
+    def test_find_affiliation_two_open_date_ranges(self):
+        # Insert another affiliation at the end of the list without
+        # including an end_date so that two records match the date.
+        self.m._data['affiliations'].append({
+            "created": 1525022430,
+            "start_date": 1458518400,
+            "owner_id": 359,
+            "last_edited": 1525022430,
+            "id": 156410,
+            "is_current": True,
+            "job_title": "Super Hacker",
+            "organization": {
+                "id": 7297,
+                "created": 1422355350,
+                "name": "Hackers 'R Us",
+                "last_edited": 1422355350
+            },
+            "end_date": None,
+        })
+
+        a = self.m.find_affiliation(datetime.datetime(2016, 4, 17))
+        self.assertEqual(
+            "Hackers 'R Us",
+            a.organization,
+        )
+
 
 class TestFetchMember(base.TestCase):