Check if two objects are deeply equal

Bun.deepEquals() checks if two objects are deeply equal. expect().toEqual() in Bun’s test runner uses it internally.

index.ts

const a = { a: 1, b: 2, c: { d: 3 } };
const b = { a: 1, b: 2, c: { d: 3 } };

Bun.deepEquals(a, b); // true

Pass true as a third argument to enable strict mode. expect().toStrictEqual() uses strict mode. The following examples return true in non-strict mode but false in strict mode.

index.ts

// undefined values
Bun.deepEquals({}, { a: undefined }, true); // false

// undefined in arrays
Bun.deepEquals(["asdf"], ["asdf", undefined], true); // false

// sparse arrays
Bun.deepEquals([, 1], [undefined, 1], true); // false

// object literals vs instances w/ same properties
class Foo {
  a = 1;
}
Bun.deepEquals(new Foo(), { a: 1 }, true); // false

See Utils.