Make sure data is available for finding exchange rates

logic.py

@@ -144,11 +144,19 @@ def get_base_band(level=None):
             return get_base_band()
     else:
         try:
-            return models.Band.objects.filter(
-                base=True
-            ).latest()
+            default_level = utils.get_standard_support_level()
+            if default_level:
+                return models.Band.objects.filter(
+                    base=True,
+                    level=default_level,
+                ).latest()
+            else:
+                return models.Band.objects.filter(
+                    base=True,
+                ).latest()
+
         except models.Band.DoesNotExist:
-            logger.warning('No base band found')
+            logger.warning('No default base band found.')
 
 
 def latest_multiplier_for_indicator(

models.py

@@ -197,7 +197,7 @@ def exchange_rate(self, base_band=None) -> Tuple[decimal.Decimal, str]:
             base_band = logic.get_base_band()
 
         if base_band:
-            base_key = base_band.country.alpha3
+            base_key = base_band.currency.region
         else:
             # This is needed during initial configuration
             base_key = '---'

tests/test_logic.py

@@ -44,24 +44,53 @@ def test_get_indicator_by_country(self):
             data = logic.get_indicator_by_country(self.fake_indicator, 2050)
             self.assertEqual(data['NLD'], 12345)
 
-    def test_get_base_band(self):
-
+    def test_get_base_band_base_level(self):
         base_band = logic.get_base_band(self.level_base)
         self.assertEqual(
             self.band_base,
             base_band,
         )
+
+    def test_get_base_band_other_level(self):
         other_base_band = logic.get_base_band(self.level_other)
         self.assertEqual(
             self.band_base_level_other,
             other_base_band,
         )
 
+    def test_get_base_band_no_args(self):
+        base_band = logic.get_base_band()
+        self.assertEqual(
+            self.band_base,
+            base_band,
+        )
+
+    def test_get_base_band_no_args_no_default_level(self):
+
+        # Make it so there is no default level
+        self.level_base.default = False
+        self.level_base.save()
+
+        base_band = logic.get_base_band()
+
+        # Restore data
+        self.level_base.default = True
+        self.level_base.save()
+
+        self.assertEqual(
+            self.band_base,
+            base_band,
+        )
+
     def test_get_base_bands(self):
 
         base_bands = logic.get_base_bands()
         self.assertListEqual(
-            [self.band_base_level_other, self.band_base],
+            [
+                self.band_base_country_other,
+                self.band_base_level_other,
+                self.band_base
+            ],
             base_bands,
         )
 

tests/test_models.py

@@ -11,6 +11,7 @@
 from django.http import HttpRequest
 
 from plugins.consortial_billing import models, plugin_settings
+from plugins.consortial_billing import utils
 from utils.testing import helpers
 from press import models as press_models
 from cms.models import Page
@@ -66,6 +67,10 @@ def setUpClass(cls):
             name='Higher',
             order=1,
         )
+        cls.level_third = models.SupportLevel.objects.create(
+            name='Even Higher',
+            order=0,
+        )
         cls.currency_base = models.Currency.objects.create(
             code='GBP',
             region='GBR',
@@ -94,6 +99,15 @@ def setUpClass(cls):
             billing_agent=cls.agent_default,
             base=True,
         )
+        cls.band_base_country_other = models.Band.objects.create(
+            size=cls.size_other,
+            country='DE',
+            currency=cls.currency_other,
+            level=cls.level_third,
+            fee=5000,
+            billing_agent=cls.agent_default,
+            base=True,
+        )
         cls.band_other_one = models.Band.objects.create(
             size=cls.size_base,
             country='GB',
@@ -174,9 +188,12 @@ def tearDownClass(cls):
         cls.supporter_one.delete()
         cls.band_other_two.delete()
         cls.band_other_one.delete()
+        cls.band_base_country_other.delete()
+        cls.band_base_level_other.delete()
         cls.band_base.delete()
         cls.currency_other.delete()
         cls.currency_base.delete()
+        cls.level_third.delete()
         cls.level_other.delete()
         cls.level_base.delete()
         cls.size_other.delete()
@@ -224,23 +241,33 @@ def test_billing_agent_save(self):
         self.assertFalse(other_has_country)
         self.assertFalse(default_still_default)
 
-    def test_currency_exchange_rate(self):
-        with patch(
-            'plugins.consortial_billing.logic.latest_multiplier_for_indicator'
-        ) as latest_multiplier:
-            self.currency_other.exchange_rate()
-            self.assertIn(
-                plugin_settings.RATE_INDICATOR,
-                latest_multiplier.call_args.args,
-            )
-            self.assertIn(
-                self.currency_other.region,
-                latest_multiplier.call_args.args,
-            )
-            self.assertIn(
-                self.currency_other.region,
-                latest_multiplier.call_args.args,
-            )
+    @patch('plugins.consortial_billing.logic.latest_multiplier_for_indicator')
+    def test_currency_exchange_rate_with_typical_args(self, latest_multiplier):
+        self.currency_base.exchange_rate(base_band=self.band_base_country_other)
+        expected_args = (
+            plugin_settings.RATE_INDICATOR,
+            self.currency_base.region,  # Target currency
+            self.currency_other.region, # Specified base currency
+            utils.setting('missing_data_exchange_rate')
+        )
+        self.assertTupleEqual(
+            expected_args,
+            latest_multiplier.call_args.args,
+        )
+
+    @patch('plugins.consortial_billing.logic.latest_multiplier_for_indicator')
+    def test_currency_exchange_rate_with_no_args(self, latest_multiplier):
+        self.currency_other.exchange_rate()
+        expected_args = (
+            plugin_settings.RATE_INDICATOR,
+            self.currency_other.region,  # Target currency
+            self.currency_base.region, # Default base currency
+            utils.setting('missing_data_exchange_rate')
+        )
+        self.assertTupleEqual(
+            expected_args,
+            latest_multiplier.call_args.args,
+        )
 
     def test_band_economic_disparity(self):
         with patch(

tests/test_views.py

@@ -52,7 +52,11 @@ def test_manager_context_essential(self, latest_multiplier):
             response.context['plugin'],
         )
         self.assertListEqual(
-            [self.band_base_level_other, self.band_base],
+            [
+                self.band_base_country_other,
+                self.band_base_level_other,
+                self.band_base
+            ],
             response.context['base_bands'],
         )
         self.assertEqual(

utils.py

@@ -170,6 +170,12 @@ def get_standard_support_level():
     try:
         return models.SupportLevel.objects.get(default=True)
     except models.SupportLevel.DoesNotExist:
+        logger.error(
+            'No default support level found. '
+            'Using the support level ordered last, '
+            'but that may produce unintended results. '
+            'For best results, set a level as the default.'
+        )
         return models.SupportLevel.objects.all().last()