normalize-ts

normalize-ts

Lenses for transformations between nexted and normalized objects.

Installation

Please note that fp-ts and monocle-ts are peer dependencies.

yarn add normalize-ts fp-ts monocle-ts

npm install normalize-ts fp-ts monocle-ts

Why?

There are a few out in the community already, with normalizr being the most popular. The problem with these are that the Typescript support could be improved and they're imperative by design. With the many users shifting to a more functional paradigm, we need something more suited.

Next in line

Here are some goals for the future, in order.

• Allow objects to have any id like {uuid: number}, not just { id: string}
• Allow own merge strategies. Currently it overwrites old data with new data.
• Allow custom types in values, instead of just arrays and objects with other lenses.
• Allow nested types with an unfold of some sort.

Example

// // Create a schema with entities

type User = {
  id: string;
  name: string;
  posts: Post[];
};

type Post = {
  id: string;
  title: string;
  description: string;
  author: User;
  collaborators: User[];
};

// ENTITIES
const user: Entity<User,'posts'> =  createEntity(() => ({
  posts: [post]
}))

const post: Entity<Post, 'author'|'collaborators'> = createEntity(() => ({
  author: user
  collaborators: [user]
}))

// SCHEMA
const schema = {
  users: user,
  posts: post
}

// GET THE MAGIC
const normalize = normalization(schema)

// NOW LET'S USE IT

const denormalized = {
  posts: {
    "99": {
      id: "99",
      title: "swampville",
      description: "shrek living happily ever after with his misses",
      author: {
        id: "11",
        name: "shrek",
        posts: ["99"],
      },
      collaborators: [
        {
          id: "22",
          name: "fiona",
          posts: ["99"],
        },
      ],
    },
  },
};

const normalized = {
  users: {
    "11": {
      id: "11",
      name: "shrek",
      posts: ["99"],
    },
    "22": {
      id: "22",
      name: "fiona",
      posts: ["99"],
    },
  },
  posts: {
    "99": {
      id: "99",
      title: "swampville",
      description: "shrek living happily ever after with his misses",
      author: "11",
      collaborators: ["22"],
    },
  },
};

expect(normalize.posts.getOption(normalized)).toStrictEqual(denormalized.posts)

// set the posts using denormalized data,
// transforming it into normalized dataa
expect(normalize.users.set(normalized.posts)).toStrictEqual(normalized)