Fix Redis#exists? to return boolean value for multiple key match.

Author: tgxworld

lib/redis.rb

@@ -584,7 +584,9 @@ def _exists(*keys)
   # @return [Boolean]
   def exists?(*keys)
     synchronize do |client|
-      client.call([:exists, *keys], &Boolify)
+      client.call([:exists, *keys]) do |value|
+        value > 0
+      end
     end
   end
 

test/lint/value_types.rb

@@ -40,6 +40,10 @@ def test_exists?
       r.set("{1}foo", "s1")
 
       assert_equal true, r.exists?("{1}foo")
+
+      r.set("{1}bar", "s1")
+
+      assert_equal true, r.exists?("{1}foo", "{1}bar")
     end
 
     def test_type