1 files changed, 36 insertions, 0 deletions
diff --git a/spec/ruby/library/stringio/pos_spec.rb b/spec/ruby/library/stringio/pos_spec.rb
new file mode 100644
index 0000000000..16f068b049
--- /dev/null
+++ b/spec/ruby/library/stringio/pos_spec.rb
@@ -0,0 +1,36 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "StringIO#pos" do
+  before :each do
+    @io = StringIOSpecs.build
+  end
+
+  it "returns the current byte offset" do
+    @io.getc
+    @io.pos.should == 1
+    @io.read(7)
+    @io.pos.should == 8
+  end
+end
+
+describe "StringIO#pos=" do
+  before :each do
+    @io = StringIOSpecs.build
+  end
+
+  it "updates the current byte offset" do
+    @io.pos = 26
+    @io.read(1).should == "r"
+  end
+
+  it "raises an EINVAL if given a negative argument" do
+    -> { @io.pos = -10 }.should.raise(Errno::EINVAL)
+  end
+
+  it "updates the current byte offset after reaching EOF" do
+    @io.read
+    @io.pos = 26
+    @io.read(1).should == "r"
+  end
+end