mongo/jstests/aggregation/extras/debug.js

function assert(b, m) {
    if (!b) alert(m);
}

function ObjectId(id) {
    return id;
}

var t1result = [
    {
        "_id" : ObjectId("4dc07fedd8420ab8d0d4066d"),
        "pageViews" : 5,
        "tags" : [
            "fun",
            "good"
        ]
    },
    {
        "_id" : ObjectId("4dc07fedd8420ab8d0d4066e"),
        "pageViews" : 7,
        "tags" : [
            "fun",
            "nasty"
        ]
    },
    {
        "_id" : ObjectId("4dc07fedd8420ab8d0d4066f"),
        "pageViews" : 6,
        "tags" : [
            "nasty",
            "filthy"
        ]
    }
];