public static String normalize()

in core/src/main/java/hudson/FilePath.java [320:375]

• 46 lines of code
• 23 McCabe index (conditional complexity)

    public static String normalize(@NonNull String path) {
        StringBuilder buf = new StringBuilder();
        // Check for prefix designating absolute path
        Matcher m = ABSOLUTE_PREFIX_PATTERN.matcher(path);
        if (m.find()) {
            buf.append(m.group(1));
            path = path.substring(m.end());
        }
        boolean isAbsolute = buf.length() > 0;
        // Split remaining path into tokens, trimming any duplicate or trailing separators
        List<String> tokens = new ArrayList<>();
        int s = 0, end = path.length();
        for (int i = 0; i < end; i++) {
            char c = path.charAt(i);
            if (c == '/' || c == '\\') {
                tokens.add(path.substring(s, i));
                s = i;
                // Skip any extra separator chars
                //noinspection StatementWithEmptyBody
                while (++i < end && ((c = path.charAt(i)) == '/' || c == '\\'))
                    ;
                // Add token for separator unless we reached the end
                if (i < end) tokens.add(path.substring(s, s+1));
                s = i;
            }
        }
        if (s < end) tokens.add(path.substring(s));
        // Look through tokens for "." or ".."
        for (int i = 0; i < tokens.size();) {
            String token = tokens.get(i);
            if (token.equals(".")) {
                tokens.remove(i);
                if (tokens.size() > 0)
                    tokens.remove(i > 0 ? i - 1 : i);
            } else if (token.equals("..")) {
                if (i == 0) {
                    // If absolute path, just remove: /../something
                    // If relative path, not collapsible so leave as-is
                    tokens.remove(0);
                    if (tokens.size() > 0) token += tokens.remove(0);
                    if (!isAbsolute) buf.append(token);
                } else {
                    // Normalize: remove something/.. plus separator before/after
                    i -= 2;
                    for (int j = 0; j < 3; j++) tokens.remove(i);
                    if (i > 0) tokens.remove(i-1);
                    else if (tokens.size() > 0) tokens.remove(0);
                }
            } else
                i += 2;
        }
        // Recombine tokens
        for (String token : tokens) buf.append(token);
        if (buf.length() == 0) buf.append('.');
        return buf.toString();
    }