filter JS complex tree with cycles

hack.ts

const ignoreKeys = new Set([
    'parent',
    'transform',
]);

const numberKeyRgx = /^[0-9]+$/;
const simpleKeyRgx = /^[a-zA-Z_\$][a-zA-Z0-9_\$]*$/;
const getExpr = function (key: string) {
    if (numberKeyRgx.test(key)) return `[${key}]`;
    return (simpleKeyRgx.test(key)) ? `.${key}` : `['${key}']`;
}

const pathMap = new Map<any, string>();
const rawPathMap = new Map<any, string[]>();
const visited = new Set<any>();

const getFromRawPath = function getFromRawPath(root: any, arr: string[]) {
    let o = root;
    for (let key of arr) o = o[key];
    return o;
}

const process = function (root, humanReadable = false) {
    pathMap.clear();
    rawPathMap.clear();
    visited.clear();
    const s = JSON.stringify(
        root,
        function (key: string, value: any) {
            if (visited.has(value)) return humanReadable ? `<REVISIT ${pathMap.get(value)}>` : `<REVISIT ${JSON.stringify(rawPathMap.get(value))}>`;
            if (ignoreKeys.has(key)) return undefined; // '<IGNORED>';
            if (typeof value === 'object' || typeof value === 'function') {
                visited.add(value);
                const ctx = pathMap.get(this);
                const path = key === '' ? 'root' : `${ctx}${getExpr(key)}`;
                pathMap.set(value, path);
                const rawCtx = rawPathMap.get(this); // @ts-ignore
                rawPathMap.set(value, key === '' ? undefined : rawCtx === undefined ? [key] : [...rawCtx, key]);
            }
            return value;
        },
        2
    );
    return JSON.parse(s);
}