text: #!/usr/bin/env python
  # edit 1
  from datetime import datetime, timedelta
  import unittest
  from app import create_app, db
  from app.models import User, Post
  from config import Config
  
  
  class TestConfig(Config):
      TESTING = True
      SQLALCHEMY_DATABASE_URI = 'sqlite://'
      ELASTICSEARCH_URL = None
  
  
  class UserModelCase(unittest.TestCase):
      def setUp(self):
          self.app = create_app(TestConfig)
          self.app_context = self.app.app_context()
          self.app_context.push()
          db.create_all()
  
      def tearDown(self):
          db.session.remove()
          db.drop_all()
          self.app_context.pop()
  
      def test_password_hashing(self):
          u = User(username='susan')
          u.set_password('cat')
          self.assertFalse(u.check_password('dog'))
          self.assertTrue(u.check_password('cat'))
  
      def test_avatar(self):
          u = User(username='john', email='john@example.com')
          self.assertEqual(u.avatar(128), ('https://www.gravatar.com/avatar/'
                                           'd4c74594d841139328695756648b6bd6'
                                           '?d=identicon&s=128'))
  
      def test_follow(self):
          u1 = User(username='john', email='john@example.com')
          u2 = User(username='susan', email='susan@example.com')
          db.session.add(u1)
          db.session.add(u2)
          db.session.commit()
          self.assertEqual(u1.followed.all(), [])
          self.assertEqual(u1.followers.all(), [])
  
          u1.follow(u2)
          db.session.commit()
          self.assertTrue(u1.is_following(u2))
          self.assertEqual(u1.followed.count(), 1)
          self.assertEqual(u1.followed.first().username, 'susan')
          self.assertEqual(u2.followers.count(), 1)
          self.assertEqual(u2.followers.first().username, 'john')
  
          u1.unfollow(u2)
          db.session.commit()
          self.assertFalse(u1.is_following(u2))
          self.assertEqual(u1.followed.count(), 0)
          self.assertEqual(u2.followers.count(), 0)
  
      def test_follow_posts(self):
          # create four users
          u1 = User(username='john', email='john@example.com')
          u2 = User(username='susan', email='susan@example.com')
          u3 = User(username='mary', email='mary@example.com')
          u4 = User(username='david', email='david@example.com')
          db.session.add_all([u1, u2, u3, u4])
  
          # create four posts
          now = datetime.utcnow()
          p1 = Post(body="post from john", author=u1,
                    timestamp=now + timedelta(seconds=1))
          p2 = Post(body="post from susan", author=u2,
                    timestamp=now + timedelta(seconds=4))
          p3 = Post(body="post from mary", author=u3,
                    timestamp=now + timedelta(seconds=3))
          p4 = Post(body="post from david", author=u4,
                    timestamp=now + timedelta(seconds=2))
          db.session.add_all([p1, p2, p3, p4])
          db.session.commit()
  
          # setup the followers
          u1.follow(u2)  # john follows susan
          u1.follow(u4)  # john follows david
          u2.follow(u3)  # susan follows mary
          u3.follow(u4)  # mary follows david
          db.session.commit()
  
          # check the followed posts of each user
          f1 = u1.followed_posts().all()
          f2 = u2.followed_posts().all()
          f3 = u3.followed_posts().all()
          f4 = u4.followed_posts().all()
          self.assertEqual(f1, [p2, p4, p1])
          self.assertEqual(f2, [p2, p3])
          self.assertEqual(f3, [p3, p4])
          self.assertEqual(f4, [p4])
  
  
  if __name__ == '__main__':
      unittest.main(verbosity=2)
  