Merge remote-tracking branch 'lest/file-realpath'

kernel/common/file19.rb

@@ -66,6 +66,27 @@ def self.world_writable?(path)
   end
 
   alias_method :to_path, :path
+
+  def self.realpath(path, basedir = nil)
+    path = expand_path(path, basedir || Dir.pwd)
+    real = ''
+    while !path.empty?
+      pos = path.index(SEPARATOR, 1)
+
+      if pos
+        name = path[0...pos]
+        path = path[pos..-1]
+      else
+        name = path
+        path = ''
+      end
+
+      real = join(real, name)
+      real = realpath(readlink(real)) if symlink?(real)
+    end
+
+    real
+  end
 end
 
 class File::Stat

spec/ruby/core/file/realpath_spec.rb

@@ -2,6 +2,46 @@
 
 ruby_version_is "1.9" do
   describe "File.realpath" do
-    it "needs to be reviewed for spec completeness"
+    before do
+      @real_dir = tmp('dir_realpath_real')
+      @link_dir = tmp('dir_realpath_link')
+
+      mkdir_p @real_dir
+      File.symlink(@real_dir, @link_dir)
+
+      @file = File.join(@real_dir, 'file')
+      @link = File.join(@link_dir, 'link')
+
+      touch @file
+      File.symlink(@file, @link)
+    end
+
+    after do
+      File.unlink @link
+      File.unlink @link_dir
+      rm_r @file, @real_dir
+    end
+
+    it "returns root for root" do
+      File.realpath('/').should == '/'
+    end
+
+    it "returns the real (absolute) pathname not containing symlinks" do
+      File.realpath(@link).should == @file
+    end
+
+    it "uses base directory for interpreting relative pathname" do
+      File.realpath(File.basename(@link), @link_dir).should == @file
+    end
+
+    it "uses current directory for interpreting relative pathname" do
+      old_dir = Dir.pwd
+      begin
+        Dir.chdir @link_dir
+        File.realpath(File.basename(@link)).should == @file
+      ensure
+        Dir.chdir old_dir
+      end
+    end
   end
 end