Merge pull request #5203 from dimagi/opm

don't crash on mothers with edd's way in the future

custom/opm/beneficiary.py

@@ -147,7 +147,12 @@ def preg_month(self):
             if not self.edd:
                 raise InvalidRow('No edd found for pregnant mother.')
             base_window_start = add_months_to_date(self.edd, -9)
-            non_adjusted_month = len(months_between(base_window_start, self.reporting_window_start)) - 1
+            try:
+                non_adjusted_month = len(months_between(base_window_start, self.reporting_window_start)) - 1
+            except AssertionError:
+                raise InvalidRow('Mother LMP ({}) was after the reporting window date ({})'.format(
+                    base_window_start, self.reporting_window_start
+                ))
 
             # the date to check one month after they first become eligible,
             # aka the end of their fourth month of pregnancy

custom/opm/tests/test_windows_and_months.py

@@ -41,6 +41,14 @@ def test_not_yet_in_range(self):
         )
         self.assertRaises(InvalidRow, MockCaseRow, case, self.report)
 
+    def test_not_yet_in_range_by_a_lot(self):
+        # 12 or more months in the future you also don't count
+        case = OPMCase(
+            forms=[],
+            edd=self._offset_date(12),
+        )
+        self.assertRaises(InvalidRow, MockCaseRow, case, self.report)
+
     def test_past_range(self):
         # anytime after the period you don't count
         case = OPMCase(