How can I use lodash to deep check the equality of two objects, ignoring undefined.
i.e.
const a = { a: 1, b: 2 };
const b = { a: 1 };
_.isEqual(a, b); // => true
You can use _.isMatch() which performs a partial deep comparison between object (a) and source (b) to determine if object contains equivalent property values to source.
const a = { a: 1, b: 2 };
const b = { a: 1 };
console.log(_.isEqual(a, b)); // false
console.log(_.isMatch(a, b)); // true
console.log(_.isMatch(b, a)); // false<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/lodash.min.js" integrity="sha512-WFN04846sdKMIP5LKNphMaWzU7YpMyCU245etK3g/2ARYbPK9Ub18eG+ljU96qKRCWh+quCY7yefSmlkQw1ANQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>This would only work if a key doesn't exist on the source. If a key exist with an explicit value of undefined, the result would be false.
const a = { a: 1, b: 2 };
const b = { a: 1, c: undefined };
console.log(_.isMatch(a, b)); // false<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/lodash.min.js" integrity="sha512-WFN04846sdKMIP5LKNphMaWzU7YpMyCU245etK3g/2ARYbPK9Ub18eG+ljU96qKRCWh+quCY7yefSmlkQw1ANQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>