Notify & subscribe user when assigned to ticket

ticket: https://todo.sr.ht/~sircmpwn/todo.sr.ht/141

tests/test_assignment.py

@@ -1,12 +1,14 @@
 from srht.database import db
 from todosrht.tickets import assign, unassign
 
-from .factories import UserFactory, TicketFactory
+from .factories import UserFactory, TrackerFactory, TicketFactory
 
 
-def test_assignment():
-    ticket = TicketFactory()
-    assigner = UserFactory()
+def test_assignment(mailbox):
+    owner = UserFactory(username="foo")
+    tracker = TrackerFactory(owner=owner, name="bar")
+    ticket = TicketFactory(tracker=tracker, scoped_id=1, title="Hilfe!")
+    assigner = UserFactory(username="assigner")
 
     assignee1 = UserFactory()
     assignee2 = UserFactory()
@@ -18,6 +20,12 @@ def test_assignment():
     db.session.commit()
     assert set(ticket.assigned_users) == {assignee1}
 
+    assert len(mailbox) == 1
+    assert mailbox[0].to == assignee1.email
+    assert mailbox[0].subject == "~foo/bar/#1: Hilfe!"
+    assert mailbox[0].body.startswith(
+        "You were assigned to ~foo/bar/#1 by ~assigner")
+
     # Assignment is idempotent
     assign(ticket, assignee1, assigner)
     db.session.commit()
@@ -27,6 +35,12 @@ def test_assignment():
     db.session.commit()
     assert set(ticket.assigned_users) == {assignee1, assignee2}
 
+    assert len(mailbox) == 2
+    assert mailbox[1].to == assignee2.email
+    assert mailbox[1].subject == "~foo/bar/#1: Hilfe!"
+    assert mailbox[1].body.startswith(
+        "You were assigned to ~foo/bar/#1 by ~assigner")
+
     unassign(ticket, assignee1, assigner)
     db.session.commit()
     assert set(ticket.assigned_users) == {assignee2}
@@ -39,3 +53,17 @@ def test_assignment():
     unassign(ticket, assignee2, assigner)
     db.session.commit()
     assert ticket.assigned_users == []
+
+    # No more emails were sent
+    assert len(mailbox) == 2
+
+def test_email_not_sent_when_self_assigned(mailbox):
+    ticket = TicketFactory()
+    user = UserFactory()
+    db.session.commit()
+
+    assign(ticket, user, user)
+    db.session.commit()
+
+    assert set(ticket.assigned_users) == {user}
+    assert len(mailbox) == 0

todosrht/emails/ticket_assigned

@@ -0,0 +1,8 @@
+{{! vim: set ft=email }}
+You were assigned to {{ ticket_path }} by {{ assigner }}.
+
+--
+
+View on the web:
+
+{{root}}{{ticket_url}}

todosrht/tickets.py

@@ -167,6 +167,29 @@ def get_or_create_subscription(ticket, user):
 
     return subscription
 
+def notify_assignee(subscription, ticket, assigner, assignee):
+    """
+    Sends a notification email to the person who was assigned to the issue.
+    """
+    ticket_path = "{}/{}/#{}".format(
+        ticket.tracker.owner.canonical_name,
+        ticket.tracker.name,
+        ticket.scoped_id)
+    subject = "{}: {}".format(ticket_path, ticket.title)
+
+    headers = {
+        "From": "~{} <{}>".format(assigner.username, notify_from),
+        "Sender": smtp_user,
+    }
+
+    context = {
+        "assigner": assigner.canonical_name,
+        "ticket_path": ticket_path,
+        "ticket_url": ticket_url(ticket).replace("%7E", "~")  # hack
+    }
+
+    notify(subscription, "ticket_assigned", subject, headers, **context)
+
 def assign(ticket, assignee, assigner):
     role = ""  # Role is not yet implemented
 
@@ -185,6 +208,10 @@ def assign(ticket, assignee, assigner):
     )
     db.session.add(ticket_assignee)
 
+    subscription = get_or_create_subscription(ticket, assignee)
+    if assigner != assignee:
+        notify_assignee(subscription, ticket, assigner, assignee)
+
     event = Event()
     event.event_type = EventType.assigned_user
     event.user_id = assigner.id