Package Exports

mutative
mutative/dist/index.js
mutative/dist/mutative.esm.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (mutative) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

mutative

Efficient creation of immutable state

10x faster than immer

Motivation

TBD

Performance

TBD

Features

apply patches
Supports optional freezing
Custom shallow copy
immutable and mutable markable
Strict mode for safer mutable data access

Difference between Immer and Mutative

-	Mutative	Immer
Best performance	✅	❌
Default common data structure	✅	❌(auto freeze)
Non-invasive marking	✅	❌
Automatic type inference	✅	❌
Complete freeze data	✅	❌

Installation

yarn install mutative # npm install mutative

Examples

const baseState = {
  foo: 'bar',
  list: [{ text: 'coding' }],
};

const state = create(baseState, (draft) => {
  draft.foo = 'foobar';
  draft.list.push({ text: 'learning' });
});

Migration from Immer to Mutative

TBD

APIs

create()

const baseState = {
  foo: 'bar',
  list: [{ text: 'todo' }],
};

const state = create(baseState, (draft) => {
  draft.foo = 'foobar';
  draft.list.push({ text: 'learning' });
});

apply()

const baseState = {
  foo: 'bar',
  list: [{ text: 'todo' }],
};

const [state, patches, inversePatches] = create(
  baseState,
  (draft) => {
    draft.foo = 'foobar';
    draft.list.push({ text: 'learning' });
  },
  {
    enablePatches: true,
  }
);

const nextState = apply(baseState, patches);
expect(nextState).toEqual(state);
const prevState = apply(state, inversePatches);
expect(prevState).toEqual(baseState);

current()

const baseState = {
  foo: 'bar',
  list: [{ text: 'todo' }],
};

const state = create(baseState, (draft) => {
  draft.foo = 'foobar';
  draft.list.push({ text: 'learning' });
  expect(current(draft.list)).toEqual([{ text: 'todo' }, { text: 'learning' }]);
});

original()

const baseState = {
  foo: 'bar',
  list: [{ text: 'todo' }],
};

const state = create(baseState, (draft) => {
  draft.foo = 'foobar';
  draft.list.push({ text: 'learning' });
  expect(original(draft.list)).toEqual([{ text: 'todo' }]);
});

isDraft()
unsafe()
castDraft()
castImmutable()
Mutable<T>
Immutable<T>
Patches
Patch

FAQs

TBD