[рони]

<script>
const container = [];
const push = (function(container) {

    const alreadyInContainerIndex = {};
    const checkItem = function(item) {
        return alreadyInContainerIndex.hasOwnProperty(item.id);
    };

    return function(data) {
        if (data && checkItem(data)) return;
        container.push(data)
        if (data) alreadyInContainerIndex[data.id] = true
    }
})(container);
push(null);
push(null);
push({id : 1})
push({id : 1})
document.write(JSON.stringify(container, null, 4))
  </script>