1 files changed, 56 insertions, 0 deletions
diff --git a/spec/ruby/core/string/length_spec.rb b/spec/ruby/core/string/length_spec.rb
new file mode 100644
index 0000000000..a723babdbc
--- /dev/null
+++ b/spec/ruby/core/string/length_spec.rb
@@ -0,0 +1,56 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "String#length" do
+  it "returns the length of self" do
+    "".length.should == 0
+    "\x00".length.should == 1
+    "one".length.should == 3
+    "two".length.should == 3
+    "three".length.should == 5
+    "four".length.should == 4
+  end
+
+  it "returns the length of a string in different encodings" do
+    utf8_str = 'こにちわ' * 100
+    utf8_str.length.should == 400
+    utf8_str.encode(Encoding::UTF_32BE).length.should == 400
+    utf8_str.encode(Encoding::SHIFT_JIS).length.should == 400
+  end
+
+  it "returns the length of the new self after encoding is changed" do
+    str = +'こにちわ'
+    str.length
+
+    str.force_encoding('BINARY').length.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.length.should == 2
+    concat.force_encoding(Encoding::ASCII_8BIT)
+    concat.length.should == 4
+  end
+
+  it "adds 1 for every invalid byte in UTF-8" do
+    "\xF4\x90\x80\x80".length.should == 4
+    "a\xF4\x90\x80\x80b".length.should == 6
+    "é\xF4\x90\x80\x80è".length.should == 6
+  end
+
+  it "adds 1 (and not 2) for a incomplete surrogate in UTF-16" do
+    "\x00\xd8".dup.force_encoding("UTF-16LE").length.should == 1
+    "\xd8\x00".dup.force_encoding("UTF-16BE").length.should == 1
+  end
+
+  it "adds 1 for a broken sequence in UTF-32" do
+    "\x04\x03\x02\x01".dup.force_encoding("UTF-32LE").length.should == 1
+    "\x01\x02\x03\x04".dup.force_encoding("UTF-32BE").length.should == 1
+  end
+end