// PeekToken returns a token at index from current position.
func (tokenizer *Tokenizer) PeekToken(index int) (token.Token, error) {
err := tokenizer.queueTokensTo(index)
if err == io.EOF {
return token.NewTokenEOF(), nil
}
if err != nil {
return token.NewEmptyToken(), err
}
return tokenizer.buffer.peek(index), nil
}
func TestTokenizerNextToken(t *testing.T) {
testData := `
{
"key": [
{
"inner1": "stringValue",
"inner2": true,
"inner3": false,
"inner4": null,
"inner5": {
"nested": -2.5e-3
}
}
]
}
`
target := tokenizer.NewTokenizer(strings.NewReader(testData))
expectedTokens := []token.Token{
token.NewToken(token.KindBeginObject, string(token.KindBeginObject)),
token.NewToken(token.KindString, "key"),
token.NewToken(token.KindSeparator, string(token.KindSeparator)),
token.NewToken(token.KindBeginArray, string(token.KindBeginArray)),
token.NewToken(token.KindBeginObject, string(token.KindBeginObject)),
token.NewToken(token.KindString, "inner1"),
token.NewToken(token.KindSeparator, string(token.KindSeparator)),
token.NewToken(token.KindString, "stringValue"),
token.NewToken(token.KindComma, string(token.KindComma)),
token.NewToken(token.KindString, "inner2"),
token.NewToken(token.KindSeparator, string(token.KindSeparator)),
token.NewToken(token.KindTrue, string(token.KindTrue)),
token.NewToken(token.KindComma, string(token.KindComma)),
token.NewToken(token.KindString, "inner3"),
token.NewToken(token.KindSeparator, string(token.KindSeparator)),
token.NewToken(token.KindFalse, string(token.KindFalse)),
token.NewToken(token.KindComma, string(token.KindComma)),
token.NewToken(token.KindString, "inner4"),
token.NewToken(token.KindSeparator, string(token.KindSeparator)),
token.NewToken(token.KindNull, string(token.KindNull)),
token.NewToken(token.KindComma, string(token.KindComma)),
token.NewToken(token.KindString, "inner5"),
token.NewToken(token.KindSeparator, string(token.KindSeparator)),
token.NewToken(token.KindBeginObject, string(token.KindBeginObject)),
token.NewToken(token.KindString, "nested"),
token.NewToken(token.KindSeparator, string(token.KindSeparator)),
token.NewToken(token.KindNumber, "-2.5e-3"),
token.NewToken(token.KindEndObject, string(token.KindEndObject)),
token.NewToken(token.KindEndObject, string(token.KindEndObject)),
token.NewToken(token.KindEndArray, string(token.KindEndArray)),
token.NewToken(token.KindEndObject, string(token.KindEndObject)),
}
for expectedIndex, expected := range expectedTokens {
actual, err := target.NextToken()
if err != nil {
t.Error(err)
}
if !expected.IsEqualTo(actual) {
t.Errorf("expected[%d] = %#v, actual = %#v\n", expectedIndex, expected, actual)
}
}
lastToken, err := target.NextToken()
if err != nil {
t.Error(err)
}
if !token.NewTokenEOF().IsEqualTo(lastToken) {
t.Error("EOF is expected")
}
}