function escapeString()

in escodegen.js [450:490]

• 35 lines of code
• 21 McCabe index (conditional complexity)

    function escapeString(str) {
        var result = '', i, len, code, singleQuotes = 0, doubleQuotes = 0, single, quote;

        for (i = 0, len = str.length; i < len; ++i) {
            code = str.charCodeAt(i);
            if (code === 0x27  /* ' */) {
                ++singleQuotes;
            } else if (code === 0x22  /* " */) {
                ++doubleQuotes;
            } else if (code === 0x2F  /* / */ && json) {
                result += '\\';
            } else if (esutils.code.isLineTerminator(code) || code === 0x5C  /* \ */) {
                result += escapeDisallowedCharacter(code);
                continue;
            } else if (!esutils.code.isIdentifierPartES5(code) && (json && code < 0x20  /* SP */ || !json && !escapeless && (code < 0x20  /* SP */ || code > 0x7E  /* ~ */))) {
                result += escapeAllowedCharacter(code, str.charCodeAt(i + 1));
                continue;
            }
            result += String.fromCharCode(code);
        }

        single = !(quotes === 'double' || (quotes === 'auto' && doubleQuotes < singleQuotes));
        quote = single ? '\'' : '"';

        if (!(single ? singleQuotes : doubleQuotes)) {
            return quote + result + quote;
        }

        str = result;
        result = quote;

        for (i = 0, len = str.length; i < len; ++i) {
            code = str.charCodeAt(i);
            if ((code === 0x27  /* ' */ && single) || (code === 0x22  /* " */ && !single)) {
                result += '\\';
            }
            result += String.fromCharCode(code);
        }

        return result + quote;
    }