/**
 * Copied from the fast-deep-equal package
 * because it does not support es modules and causes optimization bailouts.
 * TODO use the npm package again when this is merged:
 * @link https://github.com/epoberezkin/fast-deep-equal/pull/105
 */
export function deepEqual(a: any, b: any): boolean {
    if (a === b) return true;

    if (a && b && typeof a == 'object' && typeof b == 'object') {
        if (a.constructor !== b.constructor) return false;

        let length;
        let i;
        if (Array.isArray(a)) {
            length = a.length;
            if (length !== b.length) return false;
            for (i = length; i-- !== 0;)
                if (!deepEqual(a[i], b[i])) return false;
            return true;
        }


        if (a.constructor === RegExp) return a.source === b.source && a.flags === b.flags;
        if (a.valueOf !== Object.prototype.valueOf) return a.valueOf() === b.valueOf();
        if (a.toString !== Object.prototype.toString) return a.toString() === b.toString();

        const keys = Object.keys(a);
        length = keys.length;
        if (length !== Object.keys(b).length) return false;

        for (i = length; i-- !== 0;)
            if (!Object.prototype.hasOwnProperty.call(b, keys[i])) return false;

        for (i = length; i-- !== 0;) {
            const key = keys[i];
            if (!deepEqual(a[key], b[key])) return false;
        }

        return true;
    }

    // true if both NaN, false otherwise
    return a !== a && b !== b;
}