Added following

added unfollowing
added followed posts
added unit tests for User

.vscode/launch.json

@@ -11,8 +11,6 @@
             "module": "flask",
             "env": {
                 "FLASK_APP": "dvdcollection.py",
-                "MAIL_SERVER":"localhost",
-                "MAIL_PORT":8025
             },
             "args": [
                 "run",

app/models.py

@@ -42,6 +42,30 @@ def avatar(self, size):
         backref = db.backref("followers", lazy = "dynamic"), lazy="dynamic"
     )
 
+    def follow(self, user):
+        if not self.is_following(user):
+            self.followed.append(user)
+
+    def unfollow(self, user):
+        if self.is_following(user):
+            self.followed.remove(user)
+
+    def is_following(self, user):
+        return self.followed.filter(
+            followers.c.followed_id == user.id ).count() > 0
+
+    def followed_posts(self):
+        followed = Post.query.join(
+            followers, (followers.c.followed_id == Post.user_id )
+            ).filter(
+                followers.c.follower_id == self.id
+            )
+
+        own = Post.query.filter_by(user_id = self.id)
+        return followed.union(own).order_by(
+                Post.timestamp.desc()
+            )
+
 
 
 class Post(db.Model):

app/tests.py

@@ -0,0 +1,87 @@
+from datetime import datetime, timedelta
+import unittest
+
+from app import app, db
+from app.models import User, Post
+
+
+class UserModelCase(unittest.TestCase):
+    def setUp(self):
+        app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite://"
+        db.create_all()
+
+    def tearDown(self):
+        db.session.remove()
+        db.drop_all()
+
+    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 = "[email protected]")
+        self.assertEqual(u.avatar(128),('https://www.gravatar.com/avatar/'
+                                         'd4c74594d841139328695756648b6bd6'
+                                         '?d=identicon&s=128'))
+
+    def test_follow(self):
+        u1 = User(username = "john", email = "[email protected]")
+        u2 = User(username = "susan", email = "[email protected]")
+        db.session.add(u1)
+        db.session.add(u2)
+        db.session.commit()
+        self.assertEqual(u1.followed.all(), [])
+        self.assertEqual(u2.followed.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):
+        u1 = User(username = "john", email = "[email protected]")
+        u2 = User(username = "susan", email = "[email protected]")
+        u3 = User(username = "mary", email = "[email protected]")
+        u4 = User(username = "david", email = "[email protected]")
+        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])
+
+        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()
+
+        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)