Recursive Object to Dot Notation Helper

objectToDotNotation.js

const isObject = value => typeof value === 'object' && value !== null && !Array.isArray(value);

const getDottedKey = (current, parent = null) => (parent ? `${parent}.${current}` : current);

const objectToDotNotation = (value, key = null, carry = {}) => {
  if (!isObject(value) && !key) {
    return value;
  }

  if (!isObject(value)) {
    return { ...carry, [key]: value };
  }

  return Object.entries(value).reduce((childCarry, [childKey, childValue]) => (
    objectToDotNotation(childValue, getDottedKey(childKey, key), childCarry)
  ), carry);
};

objectToDotNotation_example.js

// => { foo: 'bar' }
objectToDotNotation({
  foo: 'bar'
});

// => { foo: 'bar', 'bar.baz' => 'foo' }
objectToDotNotation({
  foo: 'bar',
  bar: {
    baz: 'foo'
  }
});

// => { 'foo.bar.baz.hello': 'world!' }
objectToDotNotation({
  foo: { bar: { baz: { hello: 'world!' } } }
});

objectToDotNotation(''); // => ''
objectToDotNotation(null); // => null
objectToDotNotation(['one', 'two', 'three']) // => ['one', 'two', 'three']