Function stringInsertionPoints

json_fuzz_test.go:782–797

stringInsertionPoints returns the byte positions of all unescaped closing '"' chars that terminate a string body in data. Used by mutation operators that need to inject bytes inside a JSON string. The simple scanner does not track `\\` sequences perfectly (e.g. `\\"`), but it is good enough for fuzz

(data []byte)

// not track `\\` sequences perfectly (e.g. `\\"`), but it is good enough
// for fuzz-targeted injection.
func stringInsertionPoints(data []byte) []int {
	var pos []int
	inStr := false
	for i := 1; i < len(data); i++ {
		if data[i] != '"' || data[i-1] == '\\' {
			continue
		}
		if !inStr {
			inStr = true
		} else {
			pos = append(pos, i) // just before the closing quote
			inStr = false
		}
	}
	return pos
}

// injectInvalidUTF8 inserts a raw invalid-UTF-8 byte sequence inside a JSON
// string value. Targets the parser's UTF-8 validation path: the parser must