main.js

mydb = db.getSiblingDB("cloud-docs");

var makeData = function(n) {
    var text = "";
    var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

    for (var i = 0; i < n; i++) {
        text += possible.charAt(Math.floor(Math.random() * possible.length));
    }
    return text;
};

for (var i = 0; i < 200; i++) {
    var r = {
        filename: "sheet".concat(i),
        updated_at: new Date(),
        username: makeData(5),
        data: makeData(5000)
    };

    mydb.spreadsheets.insert(r);
}