package shell

import (
	"bufio"
	"strings"
	"testing"

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

type CharIteratorTest struct {
	suite.Suite
}

func (t *CharIteratorTest) TestNextAndBacktrack() {
	charIterator, err := NewCharIterator(bufio.NewReader(strings.NewReader("abcdefg")))
	t.NoError(err)

	t.Equal(string('a'), string(charIterator.Current()))

	err = charIterator.Next()
	t.NoError(err)

	t.Equal(string('b'), string(charIterator.Current()))

	err = charIterator.Previous()
	t.NoError(err)

	t.Equal(string('a'), string(charIterator.Current()))

	err = charIterator.Previous()
	t.Error(err)
	t.Equal("Chariterator can only go back once", err.Error())

	err = charIterator.Next()
	t.NoError(err)

	t.Equal(string('b'), string(charIterator.Current()))

}

func TestCharIteratorTest(t *testing.T) {
	suite.Run(t, new(CharIteratorTest))
}