From 0d7382407cf3af03ff7b82aee1dddfecb73e393d Mon Sep 17 00:00:00 2001
From: Christopher Charbonneau Wells <chris@chrxs.net>
Date: Mon, 30 Oct 2017 20:45:46 -0400
Subject: [PATCH] Refactor some utils functions sligthly and add tests.

---
 api/tests/__init__.py     |  0
 api/tests/tests_utils.py  | 35 +++++++++++++++++++++++++++++++++++
 api/utils.py              | 15 +++++++++++++++
 api/views.py              |  2 +-
 core/tests/tests_utils.py | 23 +++++++++++++++++++++++
 core/utils.py             | 11 -----------
 6 files changed, 74 insertions(+), 12 deletions(-)
 create mode 100644 api/tests/__init__.py
 create mode 100644 api/tests/tests_utils.py
 create mode 100644 api/utils.py
 create mode 100644 core/tests/tests_utils.py

diff --git a/api/tests/__init__.py b/api/tests/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/api/tests/tests_utils.py b/api/tests/tests_utils.py
new file mode 100644
index 00000000..7a30aadd
--- /dev/null
+++ b/api/tests/tests_utils.py
@@ -0,0 +1,35 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.test import TestCase
+from django.utils import timezone
+
+from rest_framework.views import APIView
+from rest_framework.test import APIRequestFactory
+
+from api.utils import filter_by_params
+from core.models import Child
+
+
+class UtilsTestCase(TestCase):
+    def test_filter_by_params(self):
+        factory = APIRequestFactory()
+
+        Child.objects.create(
+            first_name='First',
+            last_name='Child',
+            birth_date=timezone.localdate())
+        Child.objects.create(
+            first_name='Second',
+            last_name='Child',
+            birth_date=timezone.localdate())
+
+        request = factory.get('/children/')
+        request = APIView().initialize_request(request)
+        response = filter_by_params(request, Child, [])
+        self.assertTrue(response, Child.objects.all())
+
+        request = factory.get('/children/', {'first_name': 'First'})
+        request = APIView().initialize_request(request)
+        response = filter_by_params(request, Child, ['first_name'])
+        self.assertTrue(response, Child.objects.filter(first_name='First'))
diff --git a/api/utils.py b/api/utils.py
new file mode 100644
index 00000000..775b35cb
--- /dev/null
+++ b/api/utils.py
@@ -0,0 +1,15 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+
+def filter_by_params(request, model, available_params):
+    """Filters all instances of a model based on request parameters.
+    """
+    queryset = model.objects.all()
+
+    for param in available_params:
+        value = request.query_params.get(param, None)
+        if value is not None:
+            queryset = queryset.filter(**{param: value})
+
+    return queryset
diff --git a/api/views.py b/api/views.py
index e437086f..10d87fda 100644
--- a/api/views.py
+++ b/api/views.py
@@ -3,9 +3,9 @@ from __future__ import unicode_literals
 
 from rest_framework import viewsets
 
+from api.utils import filter_by_params
 from core.models import (Child, DiaperChange, Feeding, Note, Sleep, Timer,
                          TummyTime)
-from core.utils import filter_by_params
 
 from .serializers import (ChildSerializer, DiaperChangeSerializer,
                           FeedingSerializer, NoteSerializer, SleepSerializer,
diff --git a/core/tests/tests_utils.py b/core/tests/tests_utils.py
new file mode 100644
index 00000000..0b3fa98c
--- /dev/null
+++ b/core/tests/tests_utils.py
@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.test import TestCase
+from django.utils import timezone
+
+from core.utils import duration_string, duration_parts
+
+
+class UtilsTestCase(TestCase):
+    def test_duration_string(self):
+        duration = timezone.timedelta(hours=1, minutes=30, seconds=45)
+        self.assertEqual(
+            duration_string(duration),
+            '1 hour, 30 minutes, 45 seconds')
+        self.assertEqual(duration_string(duration, 'm'), '1 hour, 30 minutes')
+        self.assertEqual(duration_string(duration, 'h'), '1 hour')
+        self.assertRaises(TypeError, lambda: duration_string('1 hour'))
+
+    def test_duration_parts(self):
+        duration = timezone.timedelta(hours=1, minutes=30, seconds=45)
+        self.assertEqual(duration_parts(duration), (1, 30, 45))
+        self.assertRaises(TypeError, lambda: duration_parts('1 hour'))
diff --git a/core/utils.py b/core/utils.py
index 2efd7abf..3239e8db 100644
--- a/core/utils.py
+++ b/core/utils.py
@@ -4,17 +4,6 @@ from __future__ import unicode_literals
 from django.utils import timezone
 
 
-def filter_by_params(request, model, available_params):
-    queryset = model.objects.all()
-
-    for param in available_params:
-        value = request.query_params.get(param, None)
-        if value is not None:
-            queryset = queryset.filter(**{param: value})
-
-    return queryset
-
-
 def duration_string(duration, precision='s'):
     """Format hours, minutes and seconds as a human-friendly string (e.g. "2
     hours, 25 minutes, 31 seconds") with precision to h = hours, m = minutes or