Firestore REST SerDes

The Firestore REST API has a unique way of representing Documents and this module is here to provide a serializer and a deserializer that convert between ordinary JSON objects and those compatible with the Firestore REST API.

Why bother with the REST API at all?

It is not possible for the Node.js Admin SDK to make Firestore requests on behalf of a user (that is, using the ID token of a user and triggering the security rules).

In a typical scenario where

• Firestore security rules have been set up as a means of authorization
• making Firestore requests at the front end is not appropriate

we can call the Firestore REST API at the back end (e.g. Cloud Functions), with the ID token of a user and hence triggering the security rules.

How to use this module

const { serialize, deserialize } = require("firestore-rest-serdes");

Deserialization

Suppose the response of a read request contains a document like:

{
  // Other key-value pairs that we don't care
  fields: {
    hello: {
      stringValue: "world"
    },
    zero: {
      integerValue: "0"
    }
  }
}

Calling deserialize on the value of fields gives us:

{
  hello: "world",
  zero: 0
}

Serialization

Suppose we want to save the following object as a document:

{
  hello: "world",
  zero: 0
}

Calling serialize on this object gives us:

{
  hello: {
    stringValue: "world"
  },
  zero: {
    integerValue: "0"
  }
}

And then we can put the resultative object in the body of a write request.