fix: race condition for command cache (#145)

Author: supercaracal

lib/redis_client/cluster/normalized_cmd_name.rb

@@ -57,11 +57,12 @@ def extract_name_from_array(command, index:)
       end
 
       def normalize(name)
-        return @cache[name] if @cache.key?(name)
+        return @cache[name] || name.to_s.downcase if @cache.key?(name)
         return name.to_s.downcase if @mutex.locked?
 
-        @mutex.synchronize { @cache[name] = name.to_s.downcase }
-        @cache[name]
+        str = name.to_s.downcase
+        @mutex.synchronize { @cache[name] = str }
+        str
       end
     end
   end

test/redis_client/cluster/test_normalized_cmd_name.rb

@@ -63,19 +63,20 @@ def test_get_by_name
       end
 
       def test_thread_safety
-        attempts = Array.new(100, true)
+        attempts = Array.new(100, 'dummy')
+
         threads = attempts.each_with_index.map do |_, i|
           Thread.new do
             Thread.pass
             Thread.current.thread_variable_set(:index, i)
             got = if i.even?
-                    @subject.get_by_command(%w[SET foo bar]) == 'set'
+                    @subject.get_by_command(%w[SET foo bar])
                   else
-                    @subject.clear
+                    @subject.clear ? 'set' : 'clear failed'
                   end
             Thread.current.thread_variable_set(:got, got)
-          rescue StandardError
-            Thread.current.thread_variable_set(:got, false)
+          rescue StandardError => e
+            Thread.current.thread_variable_set(:got, "#{e.class.name}: #{e.message}")
           end
         end
 
@@ -84,8 +85,7 @@ def test_thread_safety
           attempts[t.thread_variable_get(:index)] = t.thread_variable_get(:got)
         end
 
-        refute_includes(attempts, false)
-        refute_includes(attempts, nil)
+        attempts.each { |got| assert_equal('set', got) }
       end
     end
   end