Function watch

Wraps the value into a proxy and returns a WatchResult to track the property (and sub-property) access of the object and compare objects.

See

WatchResult

Returns

WatchResult object that holds the proxy for the value and watcher object that tracks property access and does the comparison.

Example

Here's an example with different objects, but unchanged accessed properties:

import { watch } from '@indutny/sneequals';

const value = { a: { b: 1 } };
const { proxy, watcher } = watch(value);
const derived = watcher.unwrap({ b: proxy.a.b });

// Further access to `proxy` (or its sub-proxies) would throw.
watcher.stop();

// Prints `{ b: 1 }`
console.log(derived);

const sameProperties = { a: { b: 1 } };

// Prints `false` because these are different objects.
console.log(sameProperties === value);

// Prints `false` because the tracked `value.a.b` didn't change.
console.log(watcher.isChanged(value, sameProperties));