use unless over if !

lib/voicemeeter/configs.rb

@@ -123,7 +123,7 @@ module Voicemeeter
     public
 
     def get(kind_id)
-      if @loaders.nil?
+      unless defined? @loaders
         @loaders = Kinds::ALL.to_h { |kind| [kind.name, Loader.new(kind)] }
         @loaders.each { |name, loader| loader.run }
       end

lib/voicemeeter/event.rb

@@ -81,12 +81,12 @@ module Voicemeeter
       end
 
       def add(events)
-        events = [events] if !events.respond_to? :each
+        events = [events] unless events.respond_to? :each
         events.each { |e| send("#{e}=", true) }
       end
 
       def remove(events)
-        events = [events] if !events.respond_to? :each
+        events = [events] unless events.respond_to? :each
         events.each { |e| send("#{e}=", false) }
       end
     end

lib/voicemeeter/recorder.rb

@@ -39,7 +39,7 @@ module Voicemeeter
       end
 
       def goto(timestr)
-        if !(timestr =~ /^(2[0-3]|[01]?[0-9]):([0-5]?[0-9]):([0-5]?[0-9])$/)
+        unless /^(2[0-3]|[01]?[0-9]):([0-5]?[0-9]):([0-5]?[0-9])$/.match?(timestr)
           logger.error("goto got: '#{timestr}', but expects a time string in the format 'hh:mm:ss'")
           return
         end