package iotest

import (
	"bytes"
	"errors"
	"fmt"
	"io"
)

// OneByteReader returns a Reader that implements
// each non-empty Read by reading one byte from r.
func OneByteReader(r io.Reader) io.Reader { return &oneByteReader{r} }

type oneByteReader struct {
	r io.Reader
}

func (r *oneByteReader) Read(p []byte) (int, error) {
	if len(p) == 0 {
		return 0, nil
	}
	return r.r.Read(p[0:1])
}

import (
	"bytes"
	"errors"
	"io"
	"strings"
	"testing"
)

func TestOneByteReader_nonEmptyReader(t *testing.T) {
	msg := "Hello, World!"
	buf := new(bytes.Buffer)
	buf.WriteString(msg)

	obr := OneByteReader(buf)
	var b []byte
	n, err := obr.Read(b)
	if err != nil || n != 0 {
		t.Errorf("Empty buffer read returned n=%d err=%v", n, err)
	}

	b = make([]byte, 3)
	// Read from obr until EOF.

		t.Errorf("Read into empty buffer returned unexpected n of %d", n)
	}
}

func TestReadByOneByte(t *testing.T) {
	r := New(NewSource(1))
	b1 := make([]byte, 100)
	_, err := io.ReadFull(iotest.OneByteReader(r), b1)
	if err != nil {
		t.Errorf("read by one byte: %v", err)
	}
	r = New(NewSource(1))
	b2 := make([]byte, 100)
	_, err = r.Read(b2)
	if err != nil {
		t.Errorf("read: %v", err)
	}

		return strings.NewReader(s)
	}},
	{"ReaderOnly", func(s string) io.Reader {
		return struct{ io.Reader }{strings.NewReader(s)}
	}},
	{"OneByteReader", func(s string) io.Reader {
		return iotest.OneByteReader(strings.NewReader(s))
	}},
	{"DataErrReader", func(s string) io.Reader {
		return iotest.DataErrReader(strings.NewReader(s))
	}},
}

	}
}

type readMaker struct {
	name string
	fn   func(io.Reader) io.Reader
}

var readMakers = []readMaker{
	{"full", func(r io.Reader) io.Reader { return r }},
	{"byte", iotest.OneByteReader},
	{"half", iotest.HalfReader},
	{"data+err", iotest.DataErrReader},
	{"timeout", iotest.TimeoutReader},
}

// Call ReadString (which ends up calling everything else)
// to accumulate the text of a file.

		t.Errorf("transcript incorrect: got %x, want %x", got, chacha8hash)
	}

	p.Seed(chacha8seed)
	h.Reset()

	buf = make([]byte, chacha8outlen)
	if _, err := io.ReadFull(iotest.OneByteReader(p), buf); err != nil {
		t.Errorf("one byte reads: %v", err)
	}
	h.Write(buf)
	if got := h.Sum(nil); !bytes.Equal(got, chacha8hash) {
		t.Errorf("transcript incorrect (one byte reads): got %x, want %x", got, chacha8hash)

		{"DataErrReader", Func, 0},
		{"ErrReader", Func, 16},
		{"ErrTimeout", Var, 0},
		{"HalfReader", Func, 0},
		{"NewReadLogger", Func, 0},
		{"NewWriteLogger", Func, 0},
		{"OneByteReader", Func, 0},
		{"TestReader", Func, 16},
		{"TimeoutReader", Func, 0},
		{"TruncateWriter", Func, 0},
	},
	"testing/quick": {
		{"(*CheckEqualError).Error", Method, 0},

pkg testing/iotest, func HalfReader(io.Reader) io.Reader
pkg testing/iotest, func NewReadLogger(string, io.Reader) io.Reader
pkg testing/iotest, func NewWriteLogger(string, io.Writer) io.Writer
pkg testing/iotest, func OneByteReader(io.Reader) io.Reader
pkg testing/iotest, func TimeoutReader(io.Reader) io.Reader
pkg testing/iotest, func TruncateWriter(io.Writer, int64) io.Writer
pkg testing/iotest, var ErrTimeout error