Improve empty stream responses deserialization

Author: godric

lib/redis.rb

@@ -3518,7 +3518,7 @@ def method_missing(command, *args) # rubocop:disable Style/MissingRespondToMissi
 
   HashifyStreamEntries = lambda { |reply|
     reply.compact.map do |entry_id, values|
-      [entry_id, values.each_slice(2).to_h]
+      [entry_id, values&.each_slice(2)&.to_h]
     end
   }
 

test/streams_test.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+require_relative "helper"
+
+class TestStreams < Minitest::Test
+  include Helper::Client
+
+  def test_read_a_trimmed_entry
+    r.xgroup(:create, 'k1', 'g1', '0', mkstream: true)
+    entry_id = r.xadd('k1', { value: 'v1' })
+
+    assert_equal r.xreadgroup('g1', 'c1', 'k1', '>'), { 'k1' => [[entry_id, { 'value' => 'v1' }]] }
+    assert_equal r.xreadgroup('g1', 'c1', 'k1', '0'), { 'k1' => [[entry_id, { 'value' => 'v1' }]] }
+    r.xtrim('k1', 0)
+
+    assert_equal r.xreadgroup('g1', 'c1', 'k1', '0'), { 'k1' => [[entry_id, { 'value' => nil }]] }
+  end
+end