require_relative '../../spec_helper' require_relative 'fixtures/classes' describe "StringIO#readpartial" do before :each do @string = StringIO.new('Stop, look, listen') end after :each do @string.close unless @string.closed? end it "raises IOError on closed stream" do @string.close lambda { @string.readpartial(10) }.should raise_error(IOError) end it "reads at most the specified number of bytes" do # buffered read @string.read(1).should == 'S' # return only specified number, not the whole buffer @string.readpartial(1).should == "t" end it "reads after ungetc with data in the buffer" do c = @string.getc @string.ungetc(c) @string.readpartial(4).should == "Stop" @string.readpartial(3).should == ", l" end it "reads after ungetc without data in the buffer" do @string = StringIO.new @string.write("f").should == 1 @string.rewind c = @string.getc c.should == 'f' @string.ungetc(c).should == nil @string.readpartial(2).should == "f" @string.rewind # now, also check that the ungot char is cleared and # not returned again @string.write("b").should == 1 @string.rewind @string.readpartial(2).should == "b" end it "discards the existing buffer content upon successful read" do buffer = "existing" @string.readpartial(11, buffer) buffer.should == "Stop, look," end it "raises EOFError on EOF" do @string.readpartial(18).should == 'Stop, look, listen' lambda { @string.readpartial(10) }.should raise_error(EOFError) end it "discards the existing buffer content upon error" do buffer = 'hello' @string.readpartial(100) lambda { @string.readpartial(1, buffer) }.should raise_error(EOFError) buffer.should be_empty end it "raises IOError if the stream is closed" do @string.close lambda { @string.readpartial(1) }.should raise_error(IOError) end it "raises ArgumentError if the negative argument is provided" do lambda { @string.readpartial(-1) }.should raise_error(ArgumentError) end it "immediately returns an empty string if the length argument is 0" do @string.readpartial(0).should == "" end end