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