Modified src/0dev.org/ioutil/ioutil.go from [c11fdb5a53] to [83fc64874b].

    16     16   // An function alias type that implements io.Reader.
    17     17   type ReaderFunc func([]byte) (int, error)
    18     18   
    19     19   // Delegates the call to the WriterFunc while implementing io.Reader.
    20     20   func (r ReaderFunc) Read(b []byte) (int, error) {
    21     21   	return r(b)
    22     22   }
           23  +
           24  +// Reads a single byte from the provided io.Reader
           25  +func ReadByte(reader io.Reader) (byte, error) {
           26  +	var (
           27  +		arr [1]byte
           28  +		err error
           29  +	)
           30  +	_, err = reader.Read(arr[:])
           31  +	return arr[0], err
           32  +}
    23     33   
    24     34   // Returns a writer that delegates calls to Write(...) while ensuring
    25     35   // that it is never called with less bytes than the specified amount.
    26     36   //
    27     37   // Calls with fewer bytes are buffered while a call with a nil slice
    28     38   // causes the buffer to be flushed to the underlying writer.
    29     39   func SizedWriter(writer io.Writer, size int) io.Writer {

Modified src/0dev.org/ioutil/ioutil_test.go from [91aaac4713] to [514a112f00].

    43     43   	// Diff the result against the initial input
    44     44   	delta := diff.Diff(diff.D{len(input), len(output),
    45     45   		func(i, j int) bool { return input[i] == output[j] }})
    46     46   	if len(delta.Added) > 0 || len(delta.Removed) > 0 {
    47     47   		t.Error("Differences detected ", delta)
    48     48   	}
    49     49   }
           50  +
           51  +func TestReadByte(t *testing.T) {
           52  +	var (
           53  +		input  []byte        = []byte{255}
           54  +		reader *bytes.Reader = bytes.NewReader(input)
           55  +	)
           56  +
           57  +	result, err := ReadByte(reader)
           58  +	if result != input[0] {
           59  +		t.Error("Unexpected read result from ReadByte", result)
           60  +	}
           61  +	if err != nil {
           62  +		t.Error("Unexpected error from ReadByte", err)
           63  +	}
           64  +
           65  +	result, err = ReadByte(reader)
           66  +	if err != io.EOF {
           67  +		t.Error("Unexpected nil error from ReadByte, read value:", result)
           68  +	}
           69  +}
    50     70   
    51     71   func TestSizedWriter(t *testing.T) {
    52     72   	var (
    53     73   		buffer bytes.Buffer
    54     74   		writer io.Writer = SizedWriter(&buffer, 4)
    55     75   	)
    56     76