Add in-tree mspec and ruby/spec

* For easier modifications of ruby/spec by MRI developers.
* .gitignore: track changes under spec.
* spec/mspec, spec/rubyspec: add in-tree mspec and ruby/spec.
  These files can therefore be updated like any other file in MRI.
  Instructions are provided in spec/README.
  [Feature #13156] [ruby-core:79246]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58595 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/rubyspec/shared/file/size.rb

@@ -0,0 +1,124 @@
+describe :file_size, shared: true do
+  before :each do
+    @exists = tmp('i_exist')
+    touch(@exists) { |f| f.write 'rubinius' }
+  end
+
+  after :each do
+    rm_r @exists
+  end
+
+  it "returns the size of the file if it exists and is not empty" do
+    @object.send(@method, @exists).should == 8
+  end
+
+  it "accepts a String-like (to_str) parameter" do
+    obj = mock("file")
+    obj.should_receive(:to_str).and_return(@exists)
+
+    @object.send(@method, obj).should == 8
+  end
+
+  it "accepts an object that has a #to_path method" do
+    @object.send(@method, mock_to_path(@exists)).should == 8
+  end
+end
+
+describe :file_size_to_io, shared: true do
+  before :each do
+    @exists = tmp('i_exist')
+    touch(@exists) { |f| f.write 'rubinius' }
+    @file = File.open(@exists, 'r')
+  end
+
+  after :each do
+    @file.close unless @file.closed?
+    rm_r @exists
+  end
+
+  it "calls #to_io to convert the argument to an IO" do
+    obj = mock("io like")
+    obj.should_receive(:to_io).and_return(@file)
+
+    @object.send(@method, obj).should == 8
+  end
+end
+
+describe :file_size_raise_when_missing, shared: true do
+  before :each do
+    # TODO: missing_file
+    @missing = tmp("i_dont_exist")
+    rm_r @missing
+  end
+
+  after :each do
+    rm_r @missing
+  end
+
+  it "raises an error if file_name doesn't exist" do
+    lambda {@object.send(@method, @missing)}.should raise_error(Errno::ENOENT)
+  end
+end
+
+describe :file_size_nil_when_missing, shared: true do
+  before :each do
+    # TODO: missing_file
+    @missing = tmp("i_dont_exist")
+    rm_r @missing
+  end
+
+  after :each do
+    rm_r @missing
+  end
+
+  it "returns nil if file_name doesn't exist or has 0 size" do
+     @object.send(@method, @missing).should == nil
+  end
+end
+
+describe :file_size_0_when_empty, shared: true do
+  before :each do
+    @empty = tmp("i_am_empty")
+    touch @empty
+  end
+
+  after :each do
+    rm_r @empty
+  end
+
+  it "returns 0 if the file is empty" do
+    @object.send(@method, @empty).should == 0
+  end
+end
+
+describe :file_size_nil_when_empty, shared: true do
+  before :each do
+    @empty = tmp("i_am_empt")
+    touch @empty
+  end
+
+  after :each do
+    rm_r @empty
+  end
+
+  it "returns nil if file_name is empty" do
+    @object.send(@method, @empty).should == nil
+  end
+end
+
+describe :file_size_with_file_argument, shared: true do
+  before :each do
+    @exists = tmp('i_exist')
+    touch(@exists) { |f| f.write 'rubinius' }
+  end
+
+  after :each do
+    rm_r @exists
+  end
+
+  it "accepts a File argument" do
+    File.open(@exists) do |f|
+      @object.send(@method, f).should == 8
+    end
+  end
+end