Fix default_tags, replace += with <<

lib/datadog/tracing/contrib/patcher.rb

@@ -66,15 +66,15 @@ def on_patch_error(e)
             Datadog.health_metrics.error_instrumentation_patch(1, tags: tags)
           end
 
-          private
-
           def default_tags
             ["patcher:#{patch_name}"].tap do |tags|
               tags << "target_version:#{target_version}" if respond_to?(:target_version) && !target_version.nil?
-              tags += super if defined?(super)
+              super.each { |t| tags << t } if defined?(super)
             end
           end
 
+          private
+
           def patch_only_once
             # NOTE: This is not thread-safe
             @patch_only_once ||= Core::Utils::OnlyOnce.new

spec/datadog/tracing/contrib/redis/patcher_spec.rb

@@ -0,0 +1,23 @@
+# typed: ignore
+
+require 'datadog/tracing/contrib/support/spec_helper'
+
+require 'datadog/tracing/contrib/redis/patcher'
+
+RSpec.describe Datadog::Tracing::Contrib::Redis::Patcher do
+  describe '.default_tags' do
+    it do
+      result = described_class.default_tags
+
+      expect(result).to include(start_with('patcher:'))
+
+      if Datadog::Tracing::Contrib::Redis::Integration.redis_version
+        expect(result).to include(start_with('target_redis_version:'))
+      end
+
+      if Datadog::Tracing::Contrib::Redis::Integration.redis_client_version
+        expect(result).to include(start_with('target_redis_client_version:'))
+      end
+    end
+  end
+end