AutoPath for object keys

[kbromwich]

The AutoPath function is quite cool, but it's not clear (to me) if it's possible to use/implement the AutoPath function such that it applies to the keys of an object.

For example, Mongo allows you to perform an update with the "$set" operator, such as:

MyTable.update(id, { $set: {
  'data.subfield.value1': false,
  'data.subfield.value2': 2,
  'data.value': 'example',
} });

I'd like to add typing to a function that mimics that behaviour (and also to a function that will execute a Mongo update using the "$set" operator, but we'll stick with the mimic functionality example for now):

const indexCreate = (obj: any, key: string) => {
  let val = obj[key];
  if (val === undefined || val === null) {
    val = {};
    obj[key] = val;
  }
  return val;
};
const updateObj = <T, K extends Record<string, any>>(obj: T, dottedKeyVals: K): T => {
  const result = Array.isArray(obj) ? [...obj] : { ...obj };
  Object.entries(dottedKeyVals).forEach(([dotPath, value]) => {
    const parts = dotPath.split('.');
    const penult = parts.slice(0, -1).reduce(indexCreate, result);
    penult[parts[parts.length - 1]] = value;
  });
  return result;
};

interface SampleInterface {
  a: {
    b: number;
  };
  c: string;
}
const inputObj: SampleInterface = { a: { b: 1}, c: 'str' };
const result = updateObj(inputObj, {
  'a.b': 2,
  'c': 'newStr',
});

In the above example, is it possible to use AutoPath (or something else) to type the keys (and values) of the dottedKeyVals object (and maybe the updated obj return type as well? Though I guess that should just be T)?

Maybe this asking a bit much, though. Maybe it's a "more trouble than it's worth" situation. 😅