1 files changed, 61 insertions, 0 deletions
diff --git a/spec/rubyspec/library/stringio/printf_spec.rb b/spec/rubyspec/library/stringio/printf_spec.rb
new file mode 100644
index 0000000000..0309480a9a
--- /dev/null
+++ b/spec/rubyspec/library/stringio/printf_spec.rb
@@ -0,0 +1,61 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "StringIO#printf" do
+  before :each do
+    @io = StringIO.new('example')
+  end
+
+  it "returns nil" do
+    @io.printf("%d %04x", 123, 123).should be_nil
+  end
+
+  it "pads self with \\000 when the current position is after the end" do
+    @io.pos = 10
+    @io.printf("%d", 123)
+    @io.string.should == "example\000\000\000123"
+  end
+
+  it "performs format conversion" do
+    @io.printf("%d %04x", 123, 123)
+    @io.string.should == "123 007b"
+  end
+
+  it "updates the current position" do
+    @io.printf("%d %04x", 123, 123)
+    @io.pos.should eql(8)
+
+    @io.printf("%d %04x", 123, 123)
+    @io.pos.should eql(16)
+   end
+end
+
+describe "StringIO#printf when in append mode" do
+  before :each do
+    @io = StringIO.new("example", "a")
+  end
+
+  it "appends the passed argument to the end of self" do
+    @io.printf("%d %04x", 123, 123)
+    @io.string.should == "example123 007b"
+
+    @io.printf("%d %04x", 123, 123)
+    @io.string.should == "example123 007b123 007b"
+  end
+
+  it "correctly updates self's position" do
+    @io.printf("%d %04x", 123, 123)
+    @io.pos.should eql(15)
+  end
+end
+
+describe "StringIO#printf when self is not writable" do
+  it "raises an IOError" do
+    io = StringIO.new("test", "r")
+    lambda { io.printf("test") }.should raise_error(IOError)
+
+    io = StringIO.new("test")
+    io.close_write
+    lambda { io.printf("test") }.should raise_error(IOError)
+  end
+end