feat: add RestClient#batchPresence specs

textile/features.textile

@@ -160,6 +160,7 @@ h3(#restclient). RestClient
 ** @(RSC20e)@ Failures to log exceptions to the @errors.ably.io@ endpoint must be handled gracefully. This includes for example DNS failures, TCP/HTTP requests rejected, slow requests and internal failure errors. Additionally, as specified in @RSC20b2@, a failure to log an exception is logged with log level @info@ i.e. an exception reporting failure is not consider a client library @error@ or @warning@
 ** @(RSC20f)@ Any errors emitted by the library as a result of an internal failure must contain a status code @500@, an error code in the range @51000@ to @51999@ and a suitable error message. The error code must match one of "our common error codes":https://github.com/ably/ably-common/blob/main/protocol/errors.json
 * @(RSC22)@ @RestClient#batchPublish@ function takes a @BatchPublishSpec@ or an array of @BatchPublishSpec@s and sends then in a POST request to @/messages@ with the @newBatchResponse@ query param set to "true". When called with an array of @BatchPublishSpec@s it should return an array of @BatchResult<BatchPublishResult>@s. When called with a single @BatchPublishSpec@, the REST response will be an array containing a single @BatchResult<BatchPublishResult>@ which should be returned without the enclosing array.
+* @(RSC23)@ @RestClient#batchPresence@ function takes an array of channel name strings and sends them as a comma separated string in the @channels@ query parameter in a GET request to @/presence@ with the @newBatchResponse@ query param set to "true", returning a @BatchResult<BatchPresenceResult>@ object.
 
 h3(#rest-auth). Auth
 
@@ -1523,6 +1524,14 @@ h4. BatchPublishResult
 ** @(BPR2b)@ @messageId@ string - an optional string containing the @messageId@ prefix for the published message(s), if successful
 ** @(BPR2c)@ @error@ @ErrorInfo@ - an optional @ErrorInfo@ indicating the reason the message(s) failed to publish, if unsuccessful
 
+h4. BatchPresenceResult
+
+* @(BGR1)@ Contains information about the result of a batch presence request for a single channel
+* @(BGR2)@ The attributes of @BatchPublishChannelResult@ consist of:
+** @(BGR2a)@ @channel@ string - the name of the channel
+** @(BGR2b)@ @presence@ @PresenceMessage[]@ - an optional array containing all members present on the channel if the request succeeded
+** @(BGR2c)@ @error@ @ErrorInfo@ - an optional @ErrorInfo@ indicating the reason the presence request failed for the given channel, if unsuccessful
+
 h4. MessageFilter
 * @(MFI1)@ Supplies filter options to subscribe as defined in #RTL22
 * @(MFI2)@ Contains the following attributes:
@@ -1740,6 +1749,7 @@ class RestClient: // RSC*
   time() => io Time // RSC16
   batchPublish(BatchPublishSpec) => io BatchResult<BatchPublishResult> // RSC22
   batchPublish(BatchPublishSpec[]) => io BatchResult<BatchPublishResult>[] // RSC22
+  batchPresence(string[]) => io BatchResult<BatchPresenceResult> // RSC23
 
 class RealtimeClient: // RTC*
   constructor(keyOrTokenStr: String) // RTC12
@@ -2367,6 +2377,11 @@ class BatchPublishResult:
   channel: string // BPR2a
   messageId?: string // BPR2b
   error?: ErrorInfo // BPR2c
+
+class BatchPresenceResult:
+  channel: string // BGR2a
+  presence?: [PresenceMessage] // BGR2b
+  error?: ErrorInfo // BGR2c
 </pre>
 
 h2(#old-specs). Old specs