1 files changed, 69 insertions, 0 deletions
diff --git a/spec/ruby/core/string/getbyte_spec.rb b/spec/ruby/core/string/getbyte_spec.rb
new file mode 100644
index 0000000000..b46ab1ab64
--- /dev/null
+++ b/spec/ruby/core/string/getbyte_spec.rb
@@ -0,0 +1,69 @@
+# -*- encoding: utf-8 -*-
+require File.expand_path('../../../spec_helper', __FILE__)
+
+describe "String#getbyte" do
+  it "returns an Integer if given a valid index" do
+    "a".getbyte(0).should be_kind_of(Integer)
+  end
+
+  it "starts indexing at 0" do
+    "b".getbyte(0).should == 98
+
+    # copy-on-write case
+    _str1, str2 = "fooXbar".split("X")
+    str2.getbyte(0).should == 98
+  end
+
+  it "counts from the end of the String if given a negative argument" do
+    "glark".getbyte(-1).should == "glark".getbyte(4)
+
+    # copy-on-write case
+    _str1, str2 = "fooXbar".split("X")
+    str2.getbyte(-1).should == 114
+  end
+
+  it "returns an Integer between 0 and 255" do
+    "\x00".getbyte(0).should == 0
+    [0xFF].pack('C').getbyte(0).should == 255
+    256.chr('utf-8').getbyte(0).should == 196
+    256.chr('utf-8').getbyte(1).should == 128
+  end
+
+  it "regards a multi-byte character as having multiple bytes" do
+    chr = "\u{998}"
+    chr.bytesize.should == 3
+    chr.getbyte(0).should == 224
+    chr.getbyte(1).should == 166
+    chr.getbyte(2).should == 152
+  end
+
+  it "mirrors the output of #bytes" do
+    xDE = [0xDE].pack('C').force_encoding('utf-8')
+    str = "UTF-8 (\u{9865}} characters and hex escapes (#{xDE})"
+    str.bytes.to_a.each_with_index do |byte, index|
+      str.getbyte(index).should == byte
+    end
+  end
+
+  it "interprets bytes relative to the String's encoding" do
+    str = "\u{333}"
+    str.encode('utf-8').getbyte(0).should_not == str.encode('utf-16le').getbyte(0)
+  end
+
+  it "returns nil for out-of-bound indexes" do
+    "g".getbyte(1).should be_nil
+  end
+
+  it "regards the empty String as containing no bytes" do
+    "".getbyte(0).should be_nil
+  end
+
+  it "raises an ArgumentError unless given one argument" do
+    lambda { "glark".getbyte     }.should raise_error(ArgumentError)
+    lambda { "food".getbyte(0,0) }.should raise_error(ArgumentError)
+  end
+
+  it "raises a TypeError unless its argument can be coerced into an Integer" do
+    lambda { "a".getbyte('a') }.should raise_error(TypeError)
+  end
+end