Enable name-to-id translation for private channels

Author: eizengan

lib/slack/web/api/mixins/conversations.id.rb

@@ -14,9 +14,13 @@ module Conversations
           #   Channel to get ID for, prefixed with #.
           # @option options [integer] :id_limit
           #   The page size used for conversations_list calls required to find the channel's ID
+          # @option options [string] :id_types
+          #   The types of conversations to use when searching for the ID. A comma-separated list
+          #   containing one or more of public_channel, private_channel, mpim, im
           def conversations_id(options = {})
             name = options[:channel]
             limit = options.fetch(:id_limit, Slack::Web.config.conversations_id_page_size)
+            types = options.fetch(:id_types, nil)
 
             raise ArgumentError, 'Required arguments :channel missing' if name.nil?
 
@@ -26,7 +30,7 @@ def conversations_id(options = {})
               prefix: '#',
               enum_method: :conversations_list,
               list_method: :channels,
-              options: { limit: limit }.compact
+              options: { limit: limit, types: types }.compact
             )
           end
         end

spec/slack/web/api/mixins/conversations_spec.rb

@@ -42,6 +42,11 @@
       conversations.conversations_id(channel: '#general', id_limit: 1234)
     end
 
+    it 'forwards a provided types to the underlying conversations_list calls' do
+      expect(conversations).to receive(:conversations_list).with(types: 'public_channel,private_channel')
+      conversations.conversations_id(channel: '#general', id_types: 'public_channel,private_channel')
+    end
+
     it 'fails with an exception' do
       expect { conversations.conversations_id(channel: '#invalid') }.to(
         raise_error(Slack::Web::Api::Errors::SlackError, 'channel_not_found')