1 files changed, 51 insertions, 0 deletions
diff --git a/spec/ruby/library/stringio/each_byte_spec.rb b/spec/ruby/library/stringio/each_byte_spec.rb
new file mode 100644
index 0000000000..1be0081c1e
--- /dev/null
+++ b/spec/ruby/library/stringio/each_byte_spec.rb
@@ -0,0 +1,51 @@
+require_relative '../../spec_helper'
+require 'stringio'
+
+describe "StringIO#each_byte" do
+  before :each do
+    @io = StringIO.new("xyz")
+  end
+
+  it "yields each character code in turn" do
+    seen = []
+    @io.each_byte { |b| seen << b }
+    seen.should == [120, 121, 122]
+  end
+
+  it "updates the position before each yield" do
+    seen = []
+    @io.each_byte { |b| seen << @io.pos }
+    seen.should == [1, 2, 3]
+  end
+
+  it "does not yield if the current position is out of bounds" do
+    @io.pos = 1000
+    seen = nil
+    @io.each_byte { |b| seen = b }
+    seen.should == nil
+  end
+
+  it "returns self" do
+    @io.each_byte {}.should.equal?(@io)
+  end
+
+  it "returns an Enumerator when passed no block" do
+    enum = @io.each_byte
+    enum.instance_of?(Enumerator).should == true
+
+    seen = []
+    enum.each { |b| seen << b }
+    seen.should == [120, 121, 122]
+  end
+end
+
+describe "StringIO#each_byte when self is not readable" do
+  it "raises an IOError" do
+    io = StringIO.new(+"xyz", "w")
+    -> { io.each_byte { |b| b } }.should.raise(IOError)
+
+    io = StringIO.new("xyz")
+    io.close_read
+    -> { io.each_byte { |b| b } }.should.raise(IOError)
+  end
+end