[editor] Add new moderator:read:followers scope and pin follow subscription version

refs https://discuss.dev.twitch.tv/t/follows-endpoints-and-eventsub-subscription-type-are-now-available-in-open-beta/43322

Signed-off-by: Knut Ahlers <knut@ahlers.me>

pkg/twitch/eventsub.go

@@ -52,6 +52,10 @@ const (
 	EventSubEventTypeChannelPointCustomRewardRedemptionAdd = "channel.channel_points_custom_reward_redemption.add"
 
 	EventSubEventTypeUserAuthorizationRevoke = "user.authorization.revoke"
+
+	EventSubTopicVersion1    = "1"
+	EventSubTopicVersion2    = "2"
+	EventSubTopicVersionBeta = "beta"
 )
 
 type (
@@ -340,7 +344,11 @@ func (e *EventSubClient) PreFetchSubscriptions(ctx context.Context) error {
 	return nil
 }
 
-func (e *EventSubClient) RegisterEventSubHooks(event string, condition EventSubCondition, callback func(json.RawMessage) error) (func(), error) {
+func (e *EventSubClient) RegisterEventSubHooks(event, version string, condition EventSubCondition, callback func(json.RawMessage) error) (func(), error) {
+	if version == "" {
+		version = EventSubTopicVersion1
+	}
+
 	condHash, err := condition.Hash()
 	if err != nil {
 		return nil, errors.Wrap(err, "hashing condition")
@@ -379,7 +387,7 @@ func (e *EventSubClient) RegisterEventSubHooks(event string, condition EventSubC
 
 	newSub, err := e.twitchClient.createEventSubSubscription(ctx, eventSubSubscription{
 		Type:      event,
-		Version:   "1",
+		Version:   version,
 		Condition: condition,
 		Transport: eventSubTransport{
 			Method:   "webhook",

pkg/twitch/scopes.go

@@ -17,6 +17,7 @@ const (
 	ScopeModeratorManageChatMessages = "moderator:manage:chat_messages"
 	ScopeModeratorManageChatSettings = "moderator:manage:chat_settings"
 	ScopeModeratorManageShoutouts    = "moderator:manage:shoutouts"
+	ScopeModeratorReadFollowers      = "moderator:read:followers"
 	ScopeUserManageChatColor         = "user:manage:chat_color"
 
 	// Deprecated v5 scope but used in chat

scopes.go

@@ -11,6 +11,7 @@ var (
 		twitch.ScopeChannelManageRaids:       "start raids",
 		twitch.ScopeChannelManageVIPS:        "manage VIPs",
 		twitch.ScopeChannelReadRedemptions:   "see channel-point redemptions",
+		twitch.ScopeModeratorReadFollowers:   "see who follows this channel",
 	}
 
 	botDefaultScopes = []string{

twitchWatcher.go

@@ -18,6 +18,7 @@ type (
 		RequiredScopes []string
 		AnyScope       bool
 		Hook           func(json.RawMessage) error
+		Version        string
 	}
 
 	twitchChannelState struct {
@@ -124,8 +125,9 @@ func (t *twitchWatcher) getTopicRegistrations(userID string) []topicRegistration
 		},
 		{
 			Topic:          twitch.EventSubEventTypeChannelFollow,
+			Version:        twitch.EventSubTopicVersion1, // DEPRECATED, to be removed August 3, 2023
 			Condition:      twitch.EventSubCondition{BroadcasterUserID: userID},
-			RequiredScopes: nil,
+			RequiredScopes: nil, // Switch to []string{twitch.ScopeModeratorReadFollowers} after August 3, 2023
 			Hook:           t.handleEventSubChannelFollow,
 		},
 		{
@@ -331,7 +333,7 @@ func (t *twitchWatcher) registerEventSubCallbacks(channel string) (func(), error
 			}
 		}
 
-		uf, err := twitchEventSubClient.RegisterEventSubHooks(tr.Topic, tr.Condition, tr.Hook)
+		uf, err := twitchEventSubClient.RegisterEventSubHooks(tr.Topic, tr.Version, tr.Condition, tr.Hook)
 		if err != nil {
 			logger.WithError(err).Error("Unable to register topic")
 
@@ -356,6 +358,7 @@ func (t *twitchWatcher) registerEventSubCallbacks(channel string) (func(), error
 func (t *twitchWatcher) registerGlobalHooks() error {
 	_, err := twitchEventSubClient.RegisterEventSubHooks(
 		twitch.EventSubEventTypeUserAuthorizationRevoke,
+		twitch.EventSubTopicVersion1,
 		twitch.EventSubCondition{ClientID: cfg.TwitchClient},
 		t.handleEventUserAuthRevoke,
 	)