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Action Creator Middleware

A custom middleware that detects if an action creator has been mistakenly dispatched, instead of being called before dispatching.

A common mistake is to call dispatch(actionCreator) instead of dispatch(actionCreator()). This tends to "work" as the action creator has the static type property, but can lead to unexpected behavior.

Options​

export interface ActionCreatorInvariantMiddlewareOptions {
  /**
   * The function to identify whether a value is an action creator.
   * The default checks for a function with a static type property and match method.
   */
  isActionCreator?: (action: unknown) => action is Function & { type?: unknown }
}

Exports​

createActionCreatorInvariantMiddleware​

Creates an instance of the action creator check middleware, with the given options.

You will most likely not need to call this yourself, as getDefaultMiddleware already does so. Example:

import {
  configureStore,
  createActionCreatorInvariantMiddleware,
  Tuple,
} from '@reduxjs/toolkit'
import reducer from './reducer'

// Augment middleware to consider all functions with a static type property to be action creators
const isActionCreator = (
  action: unknown,
): action is Function & { type: unknown } =>
  typeof action === 'function' && 'type' in action

const actionCreatorMiddleware = createActionCreatorInvariantMiddleware({
  isActionCreator,
})

const store = configureStore({
  reducer,
  middleware: () => new Tuple(actionCreatorMiddleware),
})