static fixupPattern(pattern, homedir) {
        // Empty
        assert_1.default(pattern, 'pattern cannot be empty');
        // Must not contain `.` segment, unless first segment
        // Must not contain `..` segment
        const literalSegments = new internal_path_1.Path(pattern).segments.map(x => Pattern.getLiteral(x));
        assert_1.default(literalSegments.every((x, i) => (x !== '.' || i === 0) && x !== '..'), `Invalid pattern '${pattern}'. Relative pathing '.' and '..' is not allowed.`);
        // Must not contain globs in root, e.g. Windows UNC path \\foo\b*r
        assert_1.default(!pathHelper.hasRoot(pattern) || literalSegments[0], `Invalid pattern '${pattern}'. Root segment must not contain globs.`);
        // Normalize slashes
        pattern = pathHelper.normalizeSeparators(pattern);
        // Replace leading `.` segment
        if (pattern === '.' || pattern.startsWith(`.${path.sep}`)) {
            pattern = Pattern.globEscape(process.cwd()) + pattern.substr(1);
        }
        // Replace leading `~` segment
        else if (pattern === '~' || pattern.startsWith(`~${path.sep}`)) {
            homedir = homedir || os.homedir();
            assert_1.default(homedir, 'Unable to determine HOME directory');
            assert_1.default(pathHelper.hasAbsoluteRoot(homedir), `Expected HOME directory to be a rooted path. Actual '${homedir}'`);
            pattern = Pattern.globEscape(homedir) + pattern.substr(1);
        }
        // Replace relative drive root, e.g. pattern is C: or C:foo
        else if (IS_WINDOWS &&
            (pattern.match(/^[A-Z]:$/i) || pattern.match(/^[A-Z]:[^\\]/i))) {
            let root = pathHelper.ensureAbsoluteRoot('C:\\dummy-root', pattern.substr(0, 2));
            if (pattern.length > 2 && !root.endsWith('\\')) {
                root += '\\';
            }
            pattern = Pattern.globEscape(root) + pattern.substr(2);
        }
        // Replace relative root, e.g. pattern is \ or \foo
        else if (IS_WINDOWS && (pattern === '\\' || pattern.match(/^\\[^\\]/))) {
            let root = pathHelper.ensureAbsoluteRoot('C:\\dummy-root', '\\');
            if (!root.endsWith('\\')) {
                root += '\\';
            }
            pattern = Pattern.globEscape(root) + pattern.substr(1);
        }
        // Otherwise ensure absolute root
        else {
            pattern = pathHelper.ensureAbsoluteRoot(Pattern.globEscape(process.cwd()), pattern);
        }
        return pathHelper.normalizeSeparators(pattern);
    }
Normalizes slashes and ensures absolute root