implement membership

gratipay/models/team/__init__.py

@@ -33,7 +33,7 @@ def slugize(name):
     return slug
 
 
-class Team(Model, mixins.Takes, mixins.TipMigration):
+class Team(Model, mixins.Takes, mixins.TipMigration, mixins.Membership):
     """Represent a Gratipay team.
     """
 

gratipay/models/team/mixins/__init__.py

@@ -1,4 +1,5 @@
+from .membership import MembershipMixin as Membership
 from .takes import TakesMixin as Takes
 from .tip_migration import TipMigrationMixin as TipMigration
 
-__all__ = ['Takes', 'TipMigration']
+__all__ = ['Membership', 'Takes', 'TipMigration']

gratipay/models/team/mixins/membership.py

@@ -0,0 +1,54 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
+from gratipay.models.team.mixins.takes import ZERO, PENNY
+
+
+class MembershipMixin(object):
+    """Teams may have zero or more members.
+    """
+
+
+    @property
+    def nmembers(self):
+        """The number of members. Read-only and computed (not in the db); equal to
+        :py:attr:`~gratipay.models.team.mixins.takes.ndistributing_to`.
+        """
+        return self.ndistributing_to
+
+
+    def get_memberships(self, cursor=None):
+        """Return a list of membership records for this team.
+        """
+        return (cursor or self.db).all("""
+
+            SELECT ct.*
+                 , (SELECT p.*::participants
+                      FROM participants p
+                     WHERE p.id=participant_id) AS participant
+              FROM current_takes ct
+              JOIN teams t
+                ON t.id = ct.team_id
+             WHERE t.id = %s
+               AND ct.amount > 0
+
+        """, (self.id,))
+
+
+    def add_member(self, participant, recorder):
+        """Add a participant to this team.
+
+        :param Participant participant: the participant to add
+        :param Participant recorder: the participant making the change
+
+        """
+        self.set_take_for(participant, PENNY, recorder)
+
+
+    def remove_member(self, participant, recorder):
+        """Remove a participant from this team.
+
+        :param Participant participant: the participant to remove
+        :param Participant recorder: the participant making the change
+
+        """
+        self.set_take_for(participant, ZERO, recorder)

tests/py/test_team_membership.py

@@ -0,0 +1,72 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
+from test_team_takes import TeamTakesHarness
+from gratipay.models.team import mixins
+
+
+class Tests(TeamTakesHarness):
+
+    def setUp(self):
+        TeamTakesHarness.setUp(self)
+
+    def assert_memberships(self, *expected):
+        actual = self.enterprise.get_memberships()
+        assert [m.participant.username for m in actual] == list(expected)
+
+
+    def test_team_object_subclasses_takes_mixin(self):
+        assert isinstance(self.enterprise, mixins.Membership)
+
+
+    # gm - get_memberships
+
+    def test_gm_returns_an_empty_list_when_there_are_no_members(self):
+        assert self.enterprise.get_memberships() == []
+
+    def test_gm_returns_memberships_when_there_are_members(self):
+        self.enterprise.add_member(self.crusher, self.picard)
+        assert len(self.enterprise.get_memberships()) == 1
+
+    def test_gm_returns_more_memberships_when_there_are_more_members(self):
+        self.enterprise.add_member(self.crusher, self.picard)
+        self.enterprise.add_member(self.bruiser, self.picard)
+        assert len(self.enterprise.get_memberships()) == 2
+
+
+    # am - add_member
+
+    def test_am_adds_a_member(self):
+        self.enterprise.add_member(self.crusher, self.picard)
+        self.assert_memberships('crusher')
+
+    def test_am_adds_another_member(self):
+        self.enterprise.add_member(self.crusher, self.picard)
+        self.enterprise.add_member(self.bruiser, self.picard)
+        self.assert_memberships('crusher', 'bruiser')
+
+    def test_am_affects_computed_values_as_expected(self):
+        self.enterprise.add_member(self.crusher, self.picard)
+        self.enterprise.add_member(self.bruiser, self.picard)
+        assert self.enterprise.nmembers == 2
+
+
+    # rm - remove_member
+
+    def test_rm_removes_a_member(self):
+        self.enterprise.add_member(self.crusher, self.picard)
+        self.enterprise.add_member(self.bruiser, self.picard)
+        self.enterprise.remove_member(self.crusher, self.crusher)
+        self.assert_memberships('bruiser')
+
+    def test_rm_removes_another_member(self):
+        self.enterprise.add_member(self.crusher, self.picard)
+        self.enterprise.add_member(self.bruiser, self.picard)
+        self.enterprise.remove_member(self.crusher, self.crusher)
+        self.enterprise.remove_member(self.bruiser, self.picard)
+        self.assert_memberships()
+
+    def test_rm_affects_computed_values_as_expected(self):
+        self.enterprise.add_member(self.crusher, self.picard)
+        self.enterprise.add_member(self.bruiser, self.picard)
+        self.enterprise.remove_member(self.crusher, self.crusher)
+        assert self.enterprise.nmembers == 1