Delegate collections to the current database

lib/mongo/client.rb

@@ -36,8 +36,8 @@ class Client
     # @return [ Hash ] options The configuration options.
     attr_reader :options
 
-    # Delegate command execution to the current database.
-    def_delegators :@database, :command
+    # Delegate command and collections execution to the current database.
+    def_delegators :@database, :command, :collections
 
     # Delegate subscription to monitoring.
     def_delegators :@monitoring, :subscribe, :unsubscribe

spec/mongo/client_spec.rb

@@ -742,4 +742,24 @@
       expect(client.dup.options).to be_a(Mongo::Options::Redacted)
     end
   end
+
+  describe '#collections' do
+
+    before do
+      authorized_client.database[:users].create
+    end
+
+    after do
+      authorized_client.database[:users].drop
+    end
+
+    let(:collection) do
+      Mongo::Collection.new(authorized_client.database, 'users')
+    end
+
+    it 'refers the current database collections' do
+      expect(authorized_client.collections).to include(collection)
+      expect(authorized_client.collections).to all(be_a(Mongo::Collection))
+    end
+  end
 end