reducer

Declares a section of state to be calculated via a "standard" reducer function - as is typical in Redux.

This API specifically exists to help with integrations against existing Redux based libraries, and to help with gradual migration from legacy Redux code.

For example redux-first-history, requires you to attach a reducer that they provide to your store.

reducer((state = 1, action) => {
  switch (action.type) {
    case 'INCREMENT': state + 1;
    default: return state;
  }
})

Arguments

• reducer (Function, required)

  The reducer function. It receives the following arguments.

  • state (Object, required)

    The current value of the property that the reducer was attached to.

  • action (Object, required)

    The action object, typically with the following shape.

    • type (string, required)

      The name of the action.

    • payload (any)

      Any payload that was provided to the action.

Example

import { createStore, reducer, useStoreState, useStoreDispatch } from 'easy-peasy';

const store = createStore({
  counter: reducer((state = 1, action) => {
    switch (action.type) {
      case 'INCREMENT': state + 1;
      default: return state;
    }
  })
});

function Counter() {
  const count = useStoreState(state => state.counter);
  const dispatch = useStoreDispatch();
  return (
    <button onClick={() => dispatch({ type: 'INCREMENT' })}>
      {count}
    </button>
  )
}