Object utility functions

my_object.ts

interface Indexable {
  [key: string]: any;
}

function isObject(val: any): boolean {
  return Object.prototype.toString.call(val) === "[object Object]";
}

function isObjectLike(val: any): boolean {
  return val != null && typeof val === "object";
}

function isObjectEmpty(obj: Indexable): boolean {
  for (const prop in obj) {
    if (obj.hasOwnProperty(prop)) {
      return false;
    }
  }
  return true;
}

function isNullish(val: any): boolean {
  return val === null || val === undefined;
}

/*
 * { foo: { bar: "bar", baz: null } } // { foo: { bar: "bar" } }
 */
function removeNullishValues(obj) {
  for (const [key, value] of Object.entries(obj)) {
    if (isNullish(value)) {
      delete obj[key];
    } else if (isObject(value)) {
      removeNullishValues(value);
    }
  }
}

/*
 * ({ foo: "bar" }, "foo.baz") // undefined
 * ({ foo: { bar: "baz" } }, "foo.bar.baz") // undefined
 * ({ foo: { bar: "baz" } }, "foo.bar") // baz
 * ({ foo: { bar: ["baz"] } }, "foo.bar.0") // baz
 * ({ foo: { bar: null } }, "foo.bar") // null
 */
function returnValuePerFieldPath(objOrArr: any, strPath: string): any {
  function helper(struct: any, paths: string[]) {
    const p = paths.shift();
    const v = struct[p];
    if (isObjectLike(v) && paths.length) {
      return helper(v, paths);
    } else if (paths.length) {
      return undefined;
    } else {
      return v;
    }
  }
  return helper(objOrArr, strPath.split("."));
}