1 files changed, 31 insertions, 0 deletions
diff --git a/spec/ruby/library/stringio/close_write_spec.rb b/spec/ruby/library/stringio/close_write_spec.rb
new file mode 100644
index 0000000000..c86c3f9826
--- /dev/null
+++ b/spec/ruby/library/stringio/close_write_spec.rb
@@ -0,0 +1,31 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "StringIO#close_write" do
+  before :each do
+    @io = StringIO.new(+"example")
+  end
+
+  it "returns nil" do
+    @io.close_write.should be_nil
+  end
+
+  it "prevents further writing" do
+    @io.close_write
+    -> { @io.write('x') }.should raise_error(IOError)
+  end
+
+  it "allows further reading" do
+    @io.close_write
+    @io.read(1).should == 'e'
+  end
+
+  it "raises an IOError when in read-only mode" do
+    io = StringIO.new(+"example", "r")
+    -> { io.close_write }.should raise_error(IOError)
+
+    io = StringIO.new(+"example")
+    io.close_write
+    io.close_write.should == nil
+  end
+end