switch Listen::Record::SymlinkDetector::Error to use Listen::Error

lib/listen/error.rb

@@ -1,7 +1,10 @@
 # frozen_string_literal: true
 
+# Besides programming error exceptions like ArgumentError,
+# all public interface exceptions should be declared here and inherit from Listen::Error.
 module Listen
   class Error < RuntimeError
     class NotStarted < Error; end
+    class SymlinkLoop < Error; end
   end
 end

lib/listen/event/loop.rb

@@ -12,7 +12,7 @@ module Event
     class Loop
       include Listen::FSM
 
-      class Error < RuntimeError
+      module Error
         NotStarted = ::Listen::Error::NotStarted # for backward compatibility
       end
 

lib/listen/record/symlink_detector.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'set'
+require 'listen/error'
 
 module Listen
   # @private api
@@ -18,23 +19,22 @@ class SymlinkDetector
         MORE INFO: #{WIKI}
       EOS
 
-      class Error < RuntimeError
-      end
+      Error = ::Listen::Error # for backward compatibility
 
       def initialize
         @real_dirs = Set.new
       end
 
       def verify_unwatched!(entry)
         real_path = entry.real_path
-        @real_dirs.add?(real_path) || _fail(entry.sys_path, real_path)
+        @real_dirs.add?(real_path) or _fail(entry.sys_path, real_path)
       end
 
       private
 
       def _fail(symlinked, real_path)
         warn(format(SYMLINK_LOOP_ERROR, symlinked, real_path))
-        raise Error, 'Failed due to looped symlinks'
+        raise ::Listen::Error::SymlinkLoop, 'Failed due to looped symlinks'
       end
     end
   end