How to properly initialize documents in mongoose collection

Why don't you use something like this.

//Category schema//Store all the categories available in this collectionvar categorySchema=new Schema({     _id:String,//name of category     description:String     //other stuff goes here})mongoose.model(categorySchema, 'Category')//blog post schemavar postSchema=new Schema({    //all the relevant stuff    categories:[{type:String,ref:'Category'}]})

Now whenever posting a blog post, check if the categories given are already present in the Category collection. This will be fast as we are using the category name(_id) as the index itself. So for every new category you should insert in the Category collection and then insert the blog post. This way you can populate the categories array if required.

To initialise the categories, it can be done by parsing a JSON file which is more readable . The file should be parsed only when we set off with an empty database i.e when we drop the Categories collection

Create a Categories.json file. Contents of Categories.json:

[    {      _id:'Category1',//name of category     description:'description1'     ...    },    {      _id:'Category2',//name of category     description:'description2'     ...    },{      _id:'Category3',//name of category     description:'description3'     ...    }    ...]

To read the data from file

fs=require('fs');var buildCategories=fs.readFile(<path to Categories.json>,'utf8',function(err,data){              if (err) {        //logger.error(err);        return ;    }    var datafromfile=JSON.parse(data);    data.forEach(function(obj){       var catOb=new Category(obj)       obj.save(function(err,doc){..});    })});//To initialize when the Category collection is emptyCategory.findOne({},function(err,doc){    if(!doc){       //Collection is empty       //build fomr file       buildCategories();    }});//Or you can just manually call the function whenever required when server startsbuildCategories();

You could argue that you can import a csv file. But this was how I did for my project.

In my case instead of buildCategories - I've added schema method and just import initialData from json file (no need to fs.readFile).

Category.methods = {async setInitialData() {    return this.collection.insertMany(initialData, err => {        if (err){            return console.error(err);        }        console.log("Initial documents inserted to Category Collection");    });}}

Then in the controller:

Category.findOne({}, async (err,doc) => {if(!doc){    const category = new Category();    await category.setInitialData();}});