Subscription initial response should be nil

guides/subscriptions/subscription_classes.md

@@ -137,11 +137,11 @@ subscription($roomId: ID!) {
 
 If you remove `null: false`, then you can return different data in the initial subscription and the subsequent updates. (See lifecycle methods below.)
 
-Instead of a generated type, you can provide an already-configured type with `payload_type`:
+Instead of a generated type, you can provide an already-configured type with `type` just like mutations and resolvers:
 
 ```ruby
 # Just return a message
-payload_type Types::MessageType
+type Types::MessageType
 ```
 
 (In that case, don't return a hash from `#subscribe` or `#update`, return a `message` object instead.)

lib/graphql/schema/subscription.rb

@@ -15,9 +15,6 @@ class Subscription < GraphQL::Schema::Resolver
       extend GraphQL::Schema::Resolver::HasPayloadType
       extend GraphQL::Schema::Member::HasFields
       NO_UPDATE = :no_update
-      # The generated payload type is required; If there's no payload,
-      # propagate null.
-      null false
 
       # @api private
       def initialize(object:, context:, field:)
@@ -69,7 +66,7 @@ def resolve(**args)
       def resolve_subscribe(**args)
         ret_val = !args.empty? ? subscribe(**args) : subscribe
         if ret_val == :no_response
-          context.skip
+          @null ? nil : context.skip
         else
           ret_val
         end

spec/graphql/schema/subscription_spec.rb

@@ -118,7 +118,7 @@ class UsersJoinedManualPayload < GraphQL::Schema::Object
           description: "Includes newly-created users, or all users on the initial load"
       end
 
-      payload_type UsersJoinedManualPayload
+      type UsersJoinedManualPayload
 
       def subscribe
         { users: USERS.values }
@@ -137,13 +137,51 @@ class NewUsersJoined < BaseSubscription
         description: "Includes newly-created users, or all users on the initial load"
     end
 
+    # The newer API changes using type and not needing to implement the "subscribe" method
+    # which aligns with how relay or apollo digest the payload.
+    class UserChanged < BaseSubscription
+      type User
+
+      argument :handle, String, loads: User, as: :user, camelize: false
+
+      # don't need to implement the subscribe method. Returns an empty payload as
+      # the initial subscribe action shouldn't need to load any data, only when the event happens
+
+      def update(user:)
+        user
+      end
+
+      def self.visible?(context)
+        !context[:legacy_schema]
+      end
+    end
+
+    # The newer API changes using type and not needing to implement the "subscribe" method
+    # which aligns with how relay or apollo digest the payload.
+    class LegacyUserChanged < BaseSubscription
+      null true
+      payload_type User
+
+      argument :handle, String, loads: User, as: :user, camelize: false
+
+      def update(user:)
+        user
+      end
+
+      def self.visible?(context)
+        !!context[:legacy_schema]
+      end
+    end
+
     class Subscription < GraphQL::Schema::Object
       field :toot_was_tooted, subscription: TootWasTooted, extras: [:path, :query]
       field :toot_was_tooted, subscription: LegacyTootWasTooted, extras: [:path, :query]
       field :direct_toot_was_tooted, subscription: DirectTootWasTooted
       field :direct_toot_was_tooted_with_optional_scope, subscription: DirectTootWasTootedWithOptionalScope
       field :users_joined, subscription: UsersJoined
       field :new_users_joined, subscription: NewUsersJoined
+      field :user_changed, subscription: UserChanged
+      field :user_changed, subscription: LegacyUserChanged
     end
 
     class Mutation < GraphQL::Schema::Object
@@ -254,13 +292,13 @@ def in_memory_subscription_count
   end
 
   it "generates a return type" do
-    return_type = SubscriptionFieldSchema::TootWasTooted.payload_type
+    return_type = SubscriptionFieldSchema::TootWasTooted.type
     assert_equal "TootWasTootedPayload", return_type.graphql_name
     assert_equal ["toot", "user"], return_type.fields.keys
   end
 
-  it "can use a premade `payload_type`" do
-    return_type = SubscriptionFieldSchema::UsersJoined.payload_type
+  it "can use a premade `type`" do
+    return_type = SubscriptionFieldSchema::UsersJoined.type
     assert_equal "UsersJoinedManualPayload", return_type.graphql_name
     assert_equal ["users"], return_type.fields.keys
     assert_equal SubscriptionFieldSchema::UsersJoined::UsersJoinedManualPayload, return_type
@@ -304,7 +342,7 @@ def in_memory_subscription_count
       GRAPHQL
 
       expected_response = {
-        "data"=>nil,
+        "data"=> { "tootWasTooted" => nil },
         "errors"=>[
           {
             "message"=>"You don't have permission to subscribe",
@@ -328,7 +366,7 @@ def in_memory_subscription_count
       GRAPHQL
 
       expected_response = {
-        "data" => nil,
+        "data" => { "tootWasTooted" => nil },
         "errors" => [
           {
             "message"=>"No object found for `handle: \"jack\"`",
@@ -350,7 +388,7 @@ def in_memory_subscription_count
       }
       GRAPHQL
       expected_response = {
-        "data"=>nil,
+        "data"=> { "tootWasTooted" => nil },
         "errors"=>[
           {
             "message"=>"Can't subscribe to private user ([\"tootWasTooted\"])",
@@ -376,6 +414,34 @@ def in_memory_subscription_count
       assert_equal 1, in_memory_subscription_count
     end
 
+    it "sends a minimal initial response if :no_response is returned when using type instead of payload_type, which is the default" do
+      assert_equal 0, in_memory_subscription_count
+
+      res = exec_query <<-GRAPHQL
+      subscription {
+        userChanged(handle: "matz") {
+          handle
+        }
+      }
+      GRAPHQL
+      assert_equal({"data" => { "userChanged" => nil }}, res)
+      assert_equal 1, in_memory_subscription_count
+    end
+
+    it "sends no initial response if :no_response is returned when using legacy payload_type" do
+      assert_equal 0, in_memory_subscription_count
+
+      res = exec_query <<-GRAPHQL, context: { legacy_schema: true }
+      subscription {
+        userChanged(handle: "matz") {
+          handle
+        }
+      }
+      GRAPHQL
+      assert_equal({"data" => nil}, res)
+      assert_equal 1, in_memory_subscription_count
+    end
+
     it "works when there are no arguments" do
       assert_equal 0, in_memory_subscription_count
 
@@ -411,6 +477,23 @@ def in_memory_subscription_count
       assert_equal "I am a C programmer", update_payload["data"]["tootWasTooted"]["toot"]["body"]
     end
 
+    it "updates with the returned value but no initial subscription value" do
+      res = exec_query <<-GRAPHQL
+      subscription {
+        userChanged(handle: "matz") {
+          handle
+        }
+      }
+      GRAPHQL
+
+      assert_equal({"data" => { "userChanged" => nil }}, res)
+      assert_equal 1, in_memory_subscription_count
+      SubscriptionFieldSchema.subscriptions.trigger(:user_changed, { handle: "matz" }, {handle: "matz", private: false })
+
+      update = res.context[:subscription_mailbox].first
+      assert_equal "matz", update["data"]["userChanged"]["handle"]
+    end
+
     it "updates with the returned value" do
       res = exec_query <<-GRAPHQL
       subscription {