Usage

$3

interface IExample {
one: number;
two: string;
nested: IExample;
collection: IExample[];
}

const p = createProxy();

getPath(p.one); // returns ['one']
getPath(p.nested.one); // returns ['nested', 'one']
getPath(p.collection[5].nested.two); // returns ['collection', 5, 'nested', 'two']
getPath(p.three); // compilation error (no such property)

interface IExample {
one?: number;
two?: string;
nested?: IExample;
collection?: IExample[];
}

const o: IExample = {
one: 777;
collection: [
null,
{ two: 'Hello' }
]
};

get(o, p=> p.one); // returns 777
get(o, p=> p.nested.one); // returns undefined
get(o, p=> p.collection[1].two); // returns 'Hello'
get(o, p=> p.collection[0].two, 'default'); // returns 'default'
get(o, p=> p.collection[0].one, 'default'); // compilation error (property and default value types don't match)
get(o, p=> p.three); // compilation error (no such property)
const val: number = get(o, p=> p.collection[1].two); // compilation error (string is not assignable to number)

interface IExample {
one?: number;
two?: string;
nested?: IExample;
collection?: IExample[];
}

const o: IExample = {
one: 1;
};

set(o, p=> p.one, 777); // o === { one: 777 }
set(o, p=> p.nested.one, 3); // o === { one: 777, nested: { one: 3 } }
set(o, p=> p.collection[1].two, 'hello'); // o === { one: 777, nested: { one: 3 }, collection: [undefined, { two: 'hello'}] }