function scanString()

in src/impl/scanner.ts [101:178]
75 lines of code
19 McCabe index (conditional complexity)

	function scanString(): string {

		let result = '',
			start = pos;

		while (true) {
			if (pos >= len) {
				result += text.substring(start, pos);
				scanError = ScanError.UnexpectedEndOfString;
				break;
			}
			const ch = text.charCodeAt(pos);
			if (ch === CharacterCodes.doubleQuote) {
				result += text.substring(start, pos);
				pos++;
				break;
			}
			if (ch === CharacterCodes.backslash) {
				result += text.substring(start, pos);
				pos++;
				if (pos >= len) {
					scanError = ScanError.UnexpectedEndOfString;
					break;
				}
				const ch2 = text.charCodeAt(pos++);
				switch (ch2) {
					case CharacterCodes.doubleQuote:
						result += '\"';
						break;
					case CharacterCodes.backslash:
						result += '\\';
						break;
					case CharacterCodes.slash:
						result += '/';
						break;
					case CharacterCodes.b:
						result += '\b';
						break;
					case CharacterCodes.f:
						result += '\f';
						break;
					case CharacterCodes.n:
						result += '\n';
						break;
					case CharacterCodes.r:
						result += '\r';
						break;
					case CharacterCodes.t:
						result += '\t';
						break;
					case CharacterCodes.u:
						const ch3 = scanHexDigits(4, true);
						if (ch3 >= 0) {
							result += String.fromCharCode(ch3);
						} else {
							scanError = ScanError.InvalidUnicode;
						}
						break;
					default:
						scanError = ScanError.InvalidEscapeCharacter;
				}
				start = pos;
				continue;
			}
			if (ch >= 0 && ch <= 0x1f) {
				if (isLineBreak(ch)) {
					result += text.substring(start, pos);
					scanError = ScanError.UnexpectedEndOfString;
					break;
				} else {
					scanError = ScanError.InvalidCharacter;
					// mark as error but continue with string
				}
			}
			pos++;
		}
		return result;
	}