Bump utils to 40.2.1

Brings in:
- re-usable `SerialisedModel`
- speed improvements to processing CSVs against email templates

I chose not to rename `JSONModel` or `ModelList` to keep the diff nice
and small.

app/models/__init__.py

@@ -1,12 +1,13 @@
-from abc import ABC, abstractmethod
-from collections.abc import Sequence
+from abc import abstractmethod
 
 from flask import abort
+from notifications_utils.serialised_model import (
+    SerialisedModel,
+    SerialisedModelCollection,
+)
 
 
-class JSONModel():
-
-    ALLOWED_PROPERTIES = set()
+class JSONModel(SerialisedModel):
 
     def __init__(self, _dict):
         # in the case of a bad request _dict may be `None`
@@ -25,6 +26,8 @@ class JSONModel():
         return self.id == other.id
 
     def __getattribute__(self, attr):
+        # Eventually we should remove this custom implementation in
+        # favour of looping over self.ALLOWED_PROPERTIES in __init__
 
         try:
             return super().__getattribute__(attr)
@@ -54,29 +57,12 @@ class JSONModel():
             abort(404)
 
 
-class ModelList(ABC, Sequence):
+class ModelList(SerialisedModelCollection):
 
     @property
     @abstractmethod
     def client_method(self):
         pass
 
-    @property
-    @abstractmethod
-    def model(self):
-        pass
-
     def __init__(self, *args):
         self.items = self.client_method(*args)
-
-    def __getitem__(self, index):
-        return self.model(self.items[index])
-
-    def __len__(self):
-        return len(self.items)
-
-    def __add__(self, other):
-        return list(self) + list(other)
-
-    def __radd__(self, other):
-        return list(other) + list(self)

requirements-app.txt

@@ -23,7 +23,7 @@ notifications-python-client==5.6.0
 awscli-cwlogs>=1.4,<1.5
 itsdangerous==1.1.0
 
-git+https://github.com/alphagov/notifications-utils.git@40.1.0#egg=notifications-utils==40.1.0
+git+https://github.com/alphagov/notifications-utils.git@40.2.1#egg=notifications-utils==40.2.1
 git+https://github.com/alphagov/govuk-frontend-jinja.git@v0.5.1-alpha#egg=govuk-frontend-jinja==0.5.1-alpha
 
 # gds-metrics requires prometheseus 0.2.0, override that requirement as later versions bring significant performance gains

requirements.txt

@@ -25,7 +25,7 @@ notifications-python-client==5.6.0
 awscli-cwlogs>=1.4,<1.5
 itsdangerous==1.1.0
 
-git+https://github.com/alphagov/notifications-utils.git@40.1.0#egg=notifications-utils==40.1.0
+git+https://github.com/alphagov/notifications-utils.git@40.2.1#egg=notifications-utils==40.2.1
 git+https://github.com/alphagov/govuk-frontend-jinja.git@v0.5.1-alpha#egg=govuk-frontend-jinja==0.5.1-alpha
 
 # gds-metrics requires prometheseus 0.2.0, override that requirement as later versions bring significant performance gains
@@ -33,10 +33,10 @@ prometheus-client==0.8.0
 gds-metrics==0.2.0
 
 ## The following requirements were added by pip freeze:
-awscli==1.18.91
+awscli==1.18.93
 bleach==3.1.4
 boto3==1.10.38
-botocore==1.17.14
+botocore==1.17.16
 cachetools==4.1.0
 certifi==2020.6.20
 chardet==3.0.4

tests/app/models/test_base_model.py

@@ -30,14 +30,17 @@ def test_prefers_property_to_dict():
 ))
 def test_model_raises_for_unknown_attributes(json_response):
 
-    model = JSONModel(json_response)
+    class Custom(JSONModel):
+        ALLOWED_PROPERTIES = set()
+
+    model = Custom(json_response)
     assert model.ALLOWED_PROPERTIES == set()
 
     with pytest.raises(AttributeError) as e:
         model.foo
 
     assert str(e.value) == (
-        "'JSONModel' object has no attribute 'foo' and 'foo' is not a "
+        "'Custom' object has no attribute 'foo' and 'foo' is not a "
         "field in the underlying JSON"
     )
 
@@ -60,6 +63,7 @@ def test_model_raises_keyerror_if_item_missing_from_dict():
 def test_model_doesnt_swallow_attribute_errors(json_response):
 
     class Custom(JSONModel):
+        ALLOWED_PROPERTIES = set()
         @property
         def foo(self):
             raise AttributeError('Something has gone wrong')