Add endpoint to view shared spaces of a route

(https://www.pivotaltracker.com/n/projects/2533799/stories/182134179)[#182134179]

Co-authored-by: Rebecca Roberts <[email protected]>
Co-authored-by: Michael Oleske <[email protected]>

app/controllers/v3/routes_controller.rb

@@ -152,6 +152,13 @@ def unshare_route
     unprocessable!(e.message)
   end
 
+  def relationships_shared_routes
+    FeatureFlag.raise_unless_enabled!(:route_sharing)
+
+    render status: :ok, json: Presenters::V3::ToManyRelationshipPresenter.new(
+      "routes/#{route.guid}", route.shared_spaces, 'shared_spaces', build_related: false)
+  end
+
   def index_destinations
     message = RouteShowMessage.from_params({ guid: hashed_params['guid'] })
     unprocessable!(message.errors.full_messages) unless message.valid?

config/routes.rb

@@ -159,6 +159,7 @@
   post '/routes', to: 'routes#create'
   post '/routes/:guid/relationships/shared_spaces', to: 'routes#share_routes'
   delete '/routes/:guid/relationships/shared_spaces/:space_guid', to: 'routes#unshare_route'
+  get '/routes/:guid/relationships/shared_spaces', to: 'routes#relationships_shared_routes'
   patch '/routes/:guid', to: 'routes#update'
   delete '/routes/:guid', to: 'routes#destroy'
   get '/apps/:guid/routes', to: 'routes#index_by_app'

docs/v3/source/includes/experimental_resources/_share_routes.md.erb

@@ -71,3 +71,51 @@ HTTP/1.1 204 No Content
 Admin |
 Space Developer |
 Space Supporter |
+
+
+## Lists shared spaces relationship (experimental)
+
+Lists the spaces that the route has been shared to.
+
+```
+Example Request
+```
+
+```shell
+curl "https://api.example.org/v3/routes/[guid]/relationships/shared_spaces" \
+  -H "Authorization: bearer [token]" \
+  -H "Content-type: application/json"
+```
+
+```http
+HTTP/1.1 200 OK
+Content-Type: application/json
+
+{
+  "data": {
+    [
+      "guid": "space-one-guid",
+      "guid": "space-two-guid"
+    ]
+  },
+  "links": {
+    "self": {
+      "href":"http://api.example.com/v3/routes/[guid]/relationships/shared_spaces"
+    },
+  }
+}
+```
+
+#### Permitted roles
+
+ |
+--- |
+Admin |
+Admin Read-Only |
+Global Auditor |
+Org Auditor |
+Org Manager |
+Space Auditor |
+Space Developer |
+Space Manager |
+Space Supporter

spec/request/routes_spec.rb

@@ -2864,6 +2864,72 @@
       end
     end
 
+    describe 'GET /v3/routes/:guid/relationships/shared_spaces' do
+      let(:api_call) { lambda { |user_headers| get "/v3/routes/#{guid}/relationships/shared_spaces", nil, user_headers } }
+      let(:target_space_1) { VCAP::CloudController::Space.make(organization: org) }
+      let(:route) {
+        route = VCAP::CloudController::Route.make(space: space)
+        route.add_shared_space(target_space_1)
+        route
+      }
+      let(:guid) { route.guid }
+      let(:space_dev_headers) do
+        org.add_user(user)
+        space.add_developer(user)
+        headers_for(user)
+      end
+      let!(:feature_flag) do
+        VCAP::CloudController::FeatureFlag.make(name: 'route_sharing', enabled: true, error_message: nil)
+      end
+
+      before do
+        org.add_user(user)
+        target_space_1.add_developer(user)
+      end
+
+      describe 'permissions' do
+        it_behaves_like 'permissions for single object endpoint', ALL_PERMISSIONS do
+          let(:expected_codes_and_responses) do
+            h = Hash.new(code: 200, response_object: {
+              data: [
+                {
+                  guid: target_space_1.guid
+                }
+              ],
+              links: {
+                self: { href: %r(#{Regexp.escape(link_prefix)}\/v3\/routes\/#{route.guid}\/relationships\/shared_spaces) },
+              }
+            })
+
+            h['org_billing_manager'] = { code: 404 }
+            h['no_role'] = { code: 404 }
+            h
+          end
+        end
+      end
+
+      describe 'when route_sharing flag is disabled' do
+        before do
+          feature_flag.enabled = false
+          feature_flag.save
+        end
+
+        it 'makes users unable to unshare routes' do
+          api_call.call(space_dev_headers)
+
+          expect(last_response).to have_status_code(403)
+          expect(parsed_response['errors']).to include(
+            include(
+              {
+                'detail' => 'Feature Disabled: route_sharing',
+                'title' => 'CF-FeatureDisabled',
+                'code' => 330002,
+              })
+          )
+        end
+      end
+    end
+
     describe 'errors while sharing' do
       # isolation segments?
     end