Object path manipulators: simple get & set via a path w/o exceptions. Also works with numbered indecies (and nested arrays);

README.md

fromPath

const obj = {
  2: 3,
  very: {
    nested: {
      object: {
        here: '!'
      }
    }
  }
};

fromPath(obj, ''); // returns the obj itself
fromPath(obj, 'very.nested.object.here'); // '!'
fromPath(obj, 'very.nested.object'); // { here: '!' }
fromPath(obj, 2); // 3
fromPath(obj, 'very.bad.path.that.does.not.exist'); // undefined

fromPath(obj, ''); // returns the obj itself

assignToPath

const obj = {
  2: 3,
  very: {
    nested: {
      object: {
        here: '!'
      }
    }
  }
};

fromPath(obj, 2); // 3
assignToPath(obj, 2, 12); // obj[2] === 12 now
fromPath(obj, 2); // 12

assignToPath(obj, 'very.nested.object.here', '.');
fromPath(obj, 'very.nested.object.here'); // '.'

fromPath(obj, 'very.nested.object'); // { here: '.' }
assignToPath(obj, 'very.nested.object', '!');
fromPath(obj, 'very.nested.object'); // '!'

fromPath(obj, 'very.bad.path.that.does.not.exist'); // undefined
assignToPath(obj, 'very.bad.path.that.does.not.exist', 'really?');
console.log(obj); /* {
  2: 3,
  very: {
    bad: {
      path: {
        that: {
          does: {
            not: {
              exitst: 'really?'
            }
          }
        }
      }
    },
    nested: {
      object: '!'
    }
  }
} */

assignToPath.js

/**
 * assignToPath
 * Assigns a value to an object by a given path (usually string).
 * If the path is invalid, silently creates the required path and assigns a value
 *
 * @param obj an object to get a value from.
 * @param path to get a value by.
 * @param value a value to assign.
 * @param splitter to split the path by. Default is '.' ('obj.path.example')
 */
 export function assignToPath(obj, path, value, splitter = '.') {
  if (!path)
    return obj;

  const pathArr = (typeof path === 'string'  && ~path.indexOf(splitter)) ? path.split(splitter) : [path];
  const key = pathArr.pop()!;

  const final = pathArr.length === 0 ?
    obj : pathArr.reduce((o, i) => {
      if (o === Object(o)) {
        if (o[i] === undefined)
          o[i] = {};

        return o[i];
      }

      return o = {};
    }, obj);

  final[key] = value;
}

fromPath.js

/**
 * fromPath
 * Returns a value from an object by a given path (usually string).
 *
 * @param obj an object to get a value from.
 * @param path to get a value by.
 * @param splitter to split the path by. Default is '.' ('obj.path.example')
 * @returns a value from a given path. If a path is invalid - returns undefined.
 */
export function fromPath(obj, path, splitter = '.') {
  if (!path)
    return obj;

  if (typeof path === 'number' || !~path.indexOf(splitter))
    return obj[path];

  return path.split(splitter).reduce((o, i) => (o === Object(o) ? o[i] : o), obj);
}