javascript compare operators

function coercing_equal(left, right) {
    if (left === right) {
        return true ;
    }
    if (left === null) {
        return right === undefined;
    }
    if (right === null) {
        return left === undefined;
    }
    if (typeof left === 'number' && typeof right === 'string') {
        return left === +right;
    }
    if (typeof left === 'string' && typeof right === 'number') {
        return +left === right;
    }
    if (typeof left === 'boolean') {
        return coercing_equal(+left, right);
    }
    if (typeof right === 'boolean') {
        return coercing_equal(left, +right);
    }
    if
        (typeof left === 'object' &&
        (
            left.constructor === Number ||
            left.constructor === String ||
            left.constructor === Boolean
        ) &&
        (typeof right === 'string' || typeof right === 'number')
    ) {
        return coercing_equal(left.valueOf(), right);
    }
    if (
        (typeof left === 'string' || typeof left === 'number') &&
        typeof right === 'object' &&
        (
            right.constructor === Number ||
            right.constructor === String ||
            right.constructor === Boolean
        )
    ) {
        return coercing_equal(left, right.valueOf());
    }
    return false ;
}