Find a needle in a heystack in Typescript (walk object and find path of a structure)

heystack.ts

export function find(hayStack: any, magnifier: (path: string[], key: string, value: any) => boolean) {
  const foundPaths: { path: string[], key: string, value: unknown }[] = [];

  function walk(obj: any, path: string[]) {

    // console.log(path.join('.'), obj)

    if (magnifier(path, path[path.length - 1], obj)) {
      foundPaths.push({
        path: path.slice(0, path.length - 1),
        key: path[path.length - 1],
        value: obj
      })
    }

    if (typeof obj === 'object' && obj !== null) {
      for (const [k, v] of Object.entries(obj)) {
        walk(v, path.concat(k));
      }
    }

  }

  walk(hayStack, []);

  return foundPaths;
}

export function walkObjectByPath<T>(obj: any, path: string[]):T|undefined {
  let cursor = obj;
  for (const key of path) {
    cursor = cursor?.[key];
  }

  return cursor;
}
  
// example 

const hey = {
  this: {
    is: {
      an: {
        unknown: {
          object: {
            a : 1
          }
        }
      }
    }
  }
}

const needles = find(hey, (path, key, value) => key === 'a' && value ===1);
console.log(needles);
/*
[
  {
    path: [ 'this', 'is', 'an', 'unknown', 'object' ],
    key: 'a',
    value: 1
  }
]
*/

const data = walkObjectByPath(hey, needles[0].path)
console.log(data)
// { a: 1 }