@ymgn9314/ferret v0.2.1

Ferret

Ferret is a model serialization library for the Firebase JavaScript SDK.

Serialize / Deserialize

let model = new Sample();
model.id = '1';
model.name = 'sample_name';
model.createdAt = undefined;
model.updatedAt = undefined;

// Serialize
const json = serialize(model);

console.log(json);
// {
//   id: '1',
//   name: 'sample_name',
//   createdAt: FieldValue.serverTimestamp(),
//   updatedAt: FieldValue.serverTimestamp(),
// }

// Deserialize
const instance = deserialize(
  { id: '1', name: 'sample_name', createdAt: Timestamp.now(), updatedAt: Timestamp.now() },
  Sample,
);

console.log(instance);
// Sample {
//   id: '1',
//   name: 'sample_name',
//   createdAt: 2022-03-27T08:06:11.170Z, // Date
//   updatedAt: 2022-03-27T08:06:11.170Z // Date
// }

Decorators

CreatedAt

Decorator that converts to serverTimestamp() if the property is undefined when serializing. It also automatically performs normal Date⇄Timestamp conversions.

class Sample {
    @CreatedAt
    createdAt?: Date;
}

UpdatedAt

Decorator that converts to serverTimestamp each time when serializing. It also automatically performs normal Date⇄Timestamp conversions.

class Sample {
    @UpdatedAt
    updatedAt?: Date;
}

UserDefined

To have your own defined type as a property, use the UserDefined decorator. You can serialize your own types even if they use other decorators internally.

export class Child {
  id?: string;

  name?: string;

  @UpdatedAt
  updatedAt?: Date;
}

export class Parent {
  id?: string;

  @UpdatedAt
  updatedAt?: Date;

  @UserDefined(Child)
  child: Child;
}

Geo

Decorator for serializing GeoPoint in Firestore.

class Sample {
    @Geo
    geoPoint?: GeoPoint;
}

Array type support

The above decorators also support array type properties. There is no need to change any code, just make it an array type.

Attension

As of March 2022, Firestore does not support FieldValue.serverTimestamp() inside an array. Serialization itself is possible, but please design your data structure to avoid such a data structure when saving to Firestore.

export class Parent {
  id?: string;

  @UpdatedAt
  updatedAt?: Date;

  @UserDefined(Child)
  children: Child[];
}

const model = new Parent();
...
const json = serialize(model);
console.log(json);
// {
//   id: '2',
//   updatedAt: FieldValue.serverTimestamp(),
//   children: [
//     {
//       id: '0',
//       name: 'sample_name0',
//       createdAt: FieldValue.serverTimestamp(),
//       updatedAt: FieldValue.serverTimestamp(),
//     },
//     {
//       id: '1',
//       name: 'sample_name1',
//       createdAt: FieldValue.serverTimestamp(),
//       updatedAt: FieldValue.serverTimestamp(),
//     }
//   ]
// }

TODO

• Support for nested properties
• Support for Array type properties
• Implementation of additional decorators