Add GET membership API

Add an API for getting a single membership.

docs/_extra/api-reference/hypothesis-v1.yaml

@@ -880,6 +880,30 @@ paths:
                   $ref: '#/components/schemas/User'
 
   /groups/{id}/members/{user}:
+    # ----------------------------------------------------------
+    # GET groups/{id}/members/{user} - Get group member
+    # ----------------------------------------------------------
+    get:
+      tags:
+        - groups
+      summary: Get group member
+      description: Get a user's membership of a group.
+        Authenticated user must have read access to the group.
+        Does not require authentication for reading members of public groups.
+      security:
+        - ApiKey: []
+        - {}
+      parameters:
+        - $ref: '#/components/parameters/GroupID'
+        - $ref: '#/components/parameters/UserID'
+      responses:
+        '200':
+          description: Success
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Membership'
+
     # ----------------------------------------------------------
     # POST groups/{id}/members/{user} - Add user to group
     # ----------------------------------------------------------

docs/_extra/api-reference/hypothesis-v2.yaml

@@ -862,7 +862,7 @@ paths:
         Fetch a list of all members (users) in a group. Returned user resource only
         contains public-facing user data. Authenticated user must have read access
         to the group. Does not require authentication for reading members of
-        public groups. Returned members are unsorted.
+        public groups.
       security:
         - AuthClient: []
         - ApiKey: []
@@ -878,6 +878,30 @@ paths:
                   $ref: '#/components/schemas/User'
 
   /groups/{id}/members/{user}:
+    # ----------------------------------------------------------
+    # GET groups/{id}/members/{user} - Get group member
+    # ----------------------------------------------------------
+    get:
+      tags:
+        - groups
+      summary: Get group member
+      description: Fetch a user's membership of a group.
+        Authenticated user must have read access to the group.
+        Does not require authentication for reading members of public groups.
+      security:
+        - ApiKey: []
+        - {}
+      parameters:
+        - $ref: '#/components/parameters/GroupID'
+        - $ref: '#/components/parameters/UserID'
+      responses:
+        '200':
+          description: Success
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Membership'
+
     # ----------------------------------------------------------
     # POST groups/{id}/members/{user} - Add user to group
     # ----------------------------------------------------------

docs/_extra/api-reference/schemas/membership.yaml

@@ -38,4 +38,3 @@ Membership:
       format: date-time
       description: "When this membership was last updated (for example to change the role)"
       example: "1970-01-01T00:00:00.000000+00:00"
-

h/views/api/group_members.py

@@ -71,6 +71,18 @@ def list_members(context: GroupContext, request):
     return {"meta": {"page": {"total": total}}, "data": membership_dicts}
 
 
+@api_config(
+    versions=["v1", "v2"],
+    route_name="api.group_member",
+    request_method="GET",
+    link_name="group.member.read",
+    description="Fetch a group membership",
+    permission=Permission.Group.READ,
+)
+def get_member(context: GroupMembershipContext, request):
+    return GroupMembershipJSONPresenter(request, context.membership).asdict()
+
+
 @api_config(
     versions=["v1", "v2"],
     route_name="api.group_member",

tests/functional/api/groups/members_test.py

@@ -260,6 +260,119 @@ def test_it_returns_an_error_if_offset_and_limit_are_invalid(
         }
 
 
+class TestGetMember:
+    def test_it(self, app, db_session, do_request, group, target_user):
+        response = do_request()
+
+        assert response.json == {
+            "authority": group.authority,
+            "userid": target_user.userid,
+            "username": target_user.username,
+            "display_name": target_user.display_name,
+            "roles": [GroupMembershipRoles.MEMBER],
+            "actions": [
+                "delete",
+                "updates.roles.member",
+                "updates.roles.moderator",
+                "updates.roles.admin",
+                "updates.roles.owner",
+            ],
+            "created": f"1970-01-01T00:00:00.000000+00:00",
+            "updated": f"1970-01-01T00:00:01.000000+00:00",
+        }
+
+    def test_it_when_group_doesnt_exist(self, do_request):
+        response = do_request(pubid="doesnt_exist", status=404)
+
+    def test_it_when_target_user_doesnt_exist(self, do_request):
+        response = do_request(userid="doesnt_exist", status=404)
+
+    def test_it_when_authenticated_user_isnt_a_member_of_the_group(
+        self, do_request, factories, headers
+    ):
+        headers.update(
+            **token_authorization_header(
+                factories.DeveloperToken(user=factories.User())
+            )
+        )
+
+        do_request(status=404)
+
+    def test_it_when_not_authenticated(self, do_request, headers):
+        del headers["Authorization"]
+
+        do_request(status=404)
+
+    def test_it_with_an_open_group(self, do_request, factories, headers, target_user):
+        group = factories.OpenGroup(memberships=[GroupMembership(user=target_user)])
+        # Non-group members and unauthenticated requests can read the
+        # memberships of open groups.
+        del headers["Authorization"]
+
+        do_request(pubid=group.pubid)
+
+    def test_it_with_a_restricted_group(
+        self, do_request, factories, headers, target_user
+    ):
+        group = factories.RestrictedGroup(
+            memberships=[GroupMembership(user=target_user)]
+        )
+        # Non-group members and unauthenticated requests can read the
+        # memberships of restricted groups.
+        del headers["Authorization"]
+
+        do_request(pubid=group.pubid)
+
+    @pytest.fixture(autouse=True)
+    def group(self, factories):
+        return factories.Group()
+
+    @pytest.fixture(autouse=True)
+    def target_user(self, factories, group):
+        target_user = factories.User()
+        group.memberships.append(
+            GroupMembership(
+                user=target_user,
+                created=datetime(1970, 1, 1, 0, 0, 0),
+                updated=datetime(1970, 1, 1, 0, 0, 1),
+            )
+        )
+        return target_user
+
+    @pytest.fixture(autouse=True)
+    def authenticated_user(self, factories, group):
+        authenticated_user = factories.User()
+        group.memberships.append(
+            GroupMembership(
+                user=authenticated_user,
+                roles=[GroupMembershipRoles.OWNER],
+                created=datetime(1971, 1, 1, 0, 0, 0),
+                updated=datetime(1971, 1, 1, 0, 0, 1),
+            )
+        )
+        return authenticated_user
+
+    @pytest.fixture(autouse=True)
+    def token(self, factories, authenticated_user):
+        return factories.DeveloperToken(user=authenticated_user)
+
+    @pytest.fixture
+    def headers(self, factories, token):
+        return token_authorization_header(token)
+
+    @pytest.fixture
+    def do_request(self, app, db_session, group, target_user, headers):
+        def do_request(
+            pubid=group.pubid, userid=target_user.userid, headers=headers, status=200
+        ):
+            db_session.commit()
+            return app.get(
+                f"/api/groups/{pubid}/members/{userid}", headers=headers, status=status
+            )
+
+        return do_request
+
+
 class TestAddMember:
     def test_it(self, do_request, group, user):
         do_request()

tests/unit/h/views/api/group_members_test.py

@@ -122,6 +122,23 @@ def context(self, factories):
         )
 
 
+class TestGetMember:
+    def test_it(self, context, pyramid_request, GroupMembershipJSONPresenter):
+        response = views.get_member(context, pyramid_request)
+
+        GroupMembershipJSONPresenter.assert_called_once_with(
+            pyramid_request, sentinel.membership
+        )
+        GroupMembershipJSONPresenter.return_value.asdict.assert_called_once_with()
+        assert response == GroupMembershipJSONPresenter.return_value.asdict.return_value
+
+    @pytest.fixture
+    def context(self):
+        return GroupMembershipContext(
+            group=sentinel.group, user=sentinel.user, membership=sentinel.membership
+        )
+
+
 class TestRemoveMember:
     def test_it(self, context, pyramid_request, group_members_service):
         response = views.remove_member(context, pyramid_request)