Add spec for String#size

spec/core/string/shared/length.rb

@@ -0,0 +1,40 @@
+# encoding: utf-8
+
+describe :string_length, shared: true do
+  it "returns the length of self" do
+    "".send(@method).should == 0
+    "\x00".send(@method).should == 1
+    "one".send(@method).should == 3
+    "two".send(@method).should == 3
+    "three".send(@method).should == 5
+    "four".send(@method).should == 4
+  end
+
+  # NATFIXME
+  xit "returns the length of a string in different encodings" do
+    utf8_str = 'こにちわ' * 100
+    utf8_str.size.should == 400
+    utf8_str.encode(Encoding::UTF_32BE).size.should == 400
+    utf8_str.encode(Encoding::SHIFT_JIS).size.should == 400
+  end
+
+  it "returns the length of the new self after encoding is changed" do
+    str = 'こにちわ'
+    str.send(@method)
+
+    str.force_encoding('BINARY').send(@method).should == 12
+  end
+
+  it "returns the correct length after force_encoding(BINARY)" do
+    utf8 = "あ"
+    ascii = "a"
+    concat = utf8 + ascii
+
+    concat.encoding.should == Encoding::UTF_8
+    concat.bytesize.should == 4
+
+    concat.size.should == 2
+    concat.force_encoding(Encoding::ASCII_8BIT)
+    concat.size.should == 4
+  end
+end

spec/core/string/size_spec.rb

@@ -0,0 +1,7 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+require_relative 'shared/length'
+
+describe "String#size" do
+  it_behaves_like :string_length, :size
+end