ZipFsDir was in the wrong module. ZipFileSystem now has a ctor that creates ZipFsDir and ZipFsFile instances, instead of creating them lazily. It then passes the dir instance to the file instance and vice versa

zipfilesystem.rb

@@ -5,16 +5,26 @@ require 'zip'
 module Zip
   module ZipFileSystem
 
+    def initialize
+      @zipFsDir  = ZipFsDir.new(self)
+      @zipFsFile = ZipFsFile.new(self)
+      @zipFsDir.file = @zipFsFile
+      @zipFsFile.dir = @zipFsDir
+    end
+
     def dir
-      @zipFsDir ||= ZipFsDir.new(self)
+      @zipFsDir
     end
     
     def file
-      @zipFsFile ||= ZipFsFile.new(self)
+      @zipFsFile
     end
     
     class ZipFsFile
 
+      attr_writer :dir
+#      protected :dir
+
       class ZipFsStat
         def initialize(zipFsFile, entryName)
           @zipFsFile = zipFsFile
@@ -78,7 +88,7 @@ module Zip
       end
       
       def exists?(fileName)
-        expand_path(fileName) == "/" || @zipFile.find_entry(@zipFile.dir.expand_to_entry(fileName)) != nil
+        expand_path(fileName) == "/" || @zipFile.find_entry(@dir.expand_to_entry(fileName)) != nil
       end
       alias :exist? :exists?
       
@@ -113,12 +123,12 @@ module Zip
       end
 
       def directory?(fileName)
-	entry = @zipFile.find_entry(@zipFile.dir.expand_to_entry(fileName))
+	entry = @zipFile.find_entry(@dir.expand_to_entry(fileName))
 	expand_path(fileName) == "/" || (entry != nil && entry.directory?)
       end
       
       def open(fileName, openMode = "r", &block)
-        entryName = @zipFile.dir.expand_to_entry(fileName)
+        entryName = @dir.expand_to_entry(fileName)
         case openMode
         when "r" 
           @zipFile.get_input_stream(entryName, &block)
@@ -285,8 +295,7 @@ module Zip
       alias :unlink :delete
 
       def expand_path(aPath)
-        @zipFile.dir.expand_path(aPath)
-      end
+        @dir.expand_path(aPath)
       end
     end
 
@@ -294,10 +303,12 @@ module Zip
       
       def initialize(zipFile)
         @zipFile = zipFile
-      @file = @zipFile.file
         @pwd = "/"
       end
       
+      attr_writer :file
+#      protected :file
+      
       attr_reader :pwd
       alias getwd pwd
       
@@ -322,7 +333,7 @@ module Zip
       end
       
       def delete(entryName)
-      unless @zipFile.file.stat(entryName).directory?
+        unless @file.stat(entryName).directory?
           raise Errno::EINVAL, "Invalid argument - #{entryName}"
         end
         @zipFile.remove(entryName)
@@ -345,6 +356,7 @@ module Zip
         expand_path(aPath).lchop
       end
     end
+  end
 
   class ZipFile
     include ZipFileSystem