require_relative '../../spec_helper' require_relative 'fixtures/classes' require_relative 'shared/sprintf' require "stringio" describe "Kernel#printf" do it "is a private method" do Kernel.should have_private_instance_method(:printf) end end describe "Kernel.printf" do before :each do @stdout = $stdout @name = tmp("kernel_puts.txt") $stdout = new_io @name end after :each do $stdout.close $stdout = @stdout rm_r @name end it "writes to stdout when a string is the first argument" do $stdout.should_receive(:write).with("string") Kernel.printf("%s", "string") end it "calls write on the first argument when it is not a string" do object = mock('io') object.should_receive(:write).with("string") Kernel.printf(object, "%s", "string") end describe "formatting" do context "io is specified" do it_behaves_like :kernel_sprintf, -> (format, *args) { io = StringIO.new printf(io, format, *args) io.string } end context "io is not specified" do it_behaves_like :kernel_sprintf, -> (format, *args) { stdout = $stdout begin $stdout = io = StringIO.new printf(format, *args) io.string ensure $stdout = stdout end } end end end