Decode fails when input stream ends with a newline #698

import (
	"bytes"
	"encoding/json"
	"io"
	"testing"

	jsoniter "github.com/json-iterator/go"

	"github.com/stretchr/testify/require"
)

func TestJsonIterator(t *testing.T) {
	// encode jsons using the built in package
	buf := new(bytes.Buffer)
	enc := json.NewEncoder(buf)
	err := enc.Encode(map[string]string{"key": "value"})
	require.NoError(t, err)
	err = enc.Encode(map[string]string{"key2": "value2"})
	require.NoError(t, err)

	// after the last value, \n is added
	var nl byte = '\n'
	require.Equal(t, nl, buf.Bytes()[buf.Len()-1])

	// the build in package can decode the values as expected
	reader1 := bytes.NewReader(buf.Bytes())
	dec1 := json.NewDecoder(reader1)

	var res map[string]string

	err = dec1.Decode(&res)
	require.NoError(t, err)
	require.Equal(t, map[string]string{"key": "value"}, res)

	res = nil
	err = dec1.Decode(&res)
	require.NoError(t, err)
	require.Equal(t, map[string]string{"key2": "value2"}, res)

	res = nil
	err = dec1.Decode(&res)
	require.Equal(t, io.EOF, err)

	reader2 := bytes.NewReader(buf.Bytes())
	// if the last \n is removed from the input, everything works as expected
	//reader2 := bytes.NewReader(buf.Bytes()[:buf.Len()-1])

	dec2 := jsoniter.ConfigDefault.NewDecoder(reader2)

	err = dec2.Decode(&res)
	require.NoError(t, err)
	require.Equal(t, map[string]string{"key": "value"}, res)

	res = nil
	err = dec2.Decode(&res)
	require.NoError(t, err)
	require.Equal(t, map[string]string{"key2": "value2"}, res)

	res = nil
	err = dec2.Decode(&res)
	// this check fails
	// the actual error is:
	// &errors.errorString{s:"ReadMapCB: expect { or n, but found \x00, error found in #10 byte of ...|:\"value2\"}\n|..., bigger context ...|{\"key\":\"value\"}\n{\"key2\":\"value2\"}\n|..."}
	require.Equal(t, io.EOF, err)
}