feat(reading time): time taken to read an article

- add time taken to read an article
- add tests for time taken

[#Delivers 161254677]

authors/apps/article/serializers.py

@@ -3,6 +3,7 @@
  to be converted to
 native Python datatypes that can then
 be easily rendered into JSON, XML or other content types.'''
+import math
 
 from rest_framework import serializers
 from django.apps import apps
@@ -106,14 +107,35 @@ def update(self, instance, validated_data):
 
 
 class ArticleCreateSerializer(serializers.ModelSerializer):
+    time_to_read = serializers.CharField(required=False)
+    images = serializers.ListField(child=serializers.CharField(
+        max_length=1000), min_length=None, max_length=None, required=False)
+
     class Meta:
         model = TABLE
 
-        fields = fields
+        fields = fields + ('images', 'time_to_read',)
+
+    def get_time_to_read(self, body, images):
+        """
+        Calculates the time it takes to read a given article
+        average reading time for plain text = 200wpm
+        average reading time for images in articles = 15secs =0.25mins
+        """
+
+        image_view_time = 0
+        if images:
+            image_view_time = (len(images) * 0.25)
+        time_taken = math.ceil((len(list(body)) / 250) + image_view_time)
+        if time_taken <= 1:
+            return str(time_taken) + 'min'
+        return str(time_taken) + 'mins'
 
     def create(self, validated_data):
         instance = TABLE.objects.create(**validated_data)
         validated_data['slug'] = instance.slug
+        validated_data['time_to_read'] = self.get_time_to_read(
+            instance.body, validated_data.get('images'),)
 
         return validated_data
 

authors/apps/article/tests/test_article.py

@@ -43,11 +43,23 @@ def setUp(self):
                                self.user.token())
 
         self.namespace = 'article'
+        text = "Will it rain, Will it rain today, " \
+            "Will it rain today Will it rain today " \
+            "Will it rain today Will it rain today, " \
+            "Will it rain today Will it rain today " \
+            "Will it rain today Will it rain today " \
+            "Will it rain today Will it rain today," \
+            "Will it rain today Will it rain today Will it rain "
         self.body = {
             'title': faker.name(),
             'description': faker.text(),
             'body': faker.text(),
         }
+        self.article_body = {
+            "title": "Test reading time 300 ",
+            "description": "Is a new day again?",
+            "body": text
+        }
         self.create_url = reverse(self.namespace + ':create')
         self.list_url = reverse(self.namespace + ':list')
         self.update_url = reverse(
@@ -65,7 +77,12 @@ def setUp(self):
 
     def test_create_article_api(self):
         response = self.client.post(self.create_url, self.body, format='json')
+        response1 = self.client.post(
+            self.create_url,
+            self.article_body,
+            format='json')
         self.assertEqual(201, response.status_code)
+        self.assertIn('2mins', str(response1.data))
 
     def test_retrieve_article_api(self):
         response = self.client.get(self.retrieve_url)

authors/apps/article/tests/test_time_to_read.py

@@ -0,0 +1,47 @@
+from django.urls import reverse
+from rest_framework.test import APITestCase, APIClient
+
+
+class TestArticleComments(APITestCase):
+    def setUp(self):
+        """
+        Prepare test environment for each testcase
+        """
+        self.client = APIClient()
+        self.author_details = {
+            'user': {
+                'username': 'admin123',
+                'email': 'admin@admin.com',
+                'password': 'admin2018',
+            }
+        }
+        self.login_data = {
+            "user": {
+                'email': 'admin@admin.com',
+                'password': 'admin2018',
+            }
+        }
+
+        self.new_article = {
+            "title": "How to train your dragon",
+            "description": "Ever wonder how?",
+            "body": "You have to believe"
+        }
+
+        self.login_url = reverse('authentication:login')
+        self.signup_url = reverse('authentication:register')
+        self.articles_url = reverse('article:create')
+
+        self.client.post(
+            self.signup_url,
+            self.author_details,
+            format='json')
+
+    def login(self):
+        """login user to get the token"""
+        response = self.client.post(
+            self.login_url, self.login_data, format='json')
+        return response.data.get('token')
+
+    def test_time_to_read(self):
+        """This method tests the time taken to read an article"""