Writing clean, efficient, and readable code is crucial for the maintainability and scalability of any software project. Immer is a powerful library that helps developers manage immutable state in a more ergonomic and efficient way. In this blog post, we will explore some useful tips for writing efficient and readable code with Immer.

1. Use the produce function for complex updates

Immer provides a produce function that allows you to apply immutable updates to a draft state. This function takes a function as an argument and provides a mutable draft of the original state within that function. You can make any changes to the draft state as you would with mutable data, and Immer will produce a new immutable state based on these changes.

import produce from 'immer';

const state = {
  counter: 0,
  users: [],
};

const newState = produce(state, draft => {
  draft.counter += 1;
  draft.users.push({ name: 'John' });
});

console.log(newState);

Using the produce function instead of manual immutable updates not only makes the code more readable but also helps improve performance by minimizing unnecessary object cloning.

2. Apply updates in a single immer call

When working with Immer, it’s best to apply updates in a single produce call whenever possible. This ensures that Immer can optimize the immutable updates and minimize unnecessary object cloning. Applying updates within nested produce calls can lead to unnecessary performance overhead.

import produce from 'immer';

const state = {
  todos: [
    { id: 1, text: 'Buy groceries', completed: false },
    { id: 2, text: 'Clean the house', completed: true },
  ],
};

// Good: apply updates in a single immer call
const newState = produce(state, draft => {
  draft.todos[0].completed = true;
  // more updates...
});

// Avoid: applying updates within nested produce calls
const updatedState = produce(state, draft => {
  produce(draft.todos[0], todo => {
    todo.completed = true;
  });
  // more updates...
});

By applying updates in a single Immer call, the library can optimize the immutability updates and improve performance.

Conclusion

Immer is a powerful library for managing immutable state in a more efficient and readable way. By following these tips, you can write cleaner and more performant code with Immer. Remember to use the produce function for complex updates and apply updates in a single immer call whenever possible. Happy coding!

#Immer #JavaScript