require_relative '../../spec_helper' require_relative 'fixtures/classes' require_relative '../../core/kernel/shared/sprintf' 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 describe "formatting" do it_behaves_like :kernel_sprintf, -> format, *args { io = StringIO.new(+"") io.printf(format, *args) io.string } 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") -> { io.printf("test") }.should raise_error(IOError) io = StringIO.new("test") io.close_write -> { io.printf("test") }.should raise_error(IOError) end end