Add badly typed support for an "extra" arg on creation

Also use ThunkDispatch as the default type

Author: markerikson

packages/action-listener-middleware/src/index.ts

@@ -7,6 +7,7 @@ import {
   AnyAction,
   MiddlewareAPI,
   Action,
+  ThunkDispatch,
 } from '@reduxjs/toolkit'
 
 interface BaseActionCreator<P, T extends string, M = never, E = never> {
@@ -61,6 +62,8 @@ export interface ActionListenerMiddlewareAPI<
 > extends MiddlewareAPI<D, S> {
   unsubscribe(): void
   currentPhase: MiddlewarePhase
+  // TODO Figure out how to pass this through the other types correctly
+  extra: unknown
 }
 
 /**
@@ -82,6 +85,10 @@ export interface ActionListenerOptions {
   when?: When
 }
 
+export interface CreateListenerMiddlewareOptions<ExtraArgument = unknown> {
+  extra?: ExtraArgument
+}
+
 export interface AddListenerAction<
   A extends AnyAction,
   S,
@@ -201,8 +208,10 @@ const actualMiddlewarePhases = ['beforeReducer', 'afterReducer'] as const
  */
 export function createActionListenerMiddleware<
   S,
-  D extends Dispatch<AnyAction> = Dispatch
->() {
+  // TODO Carry through the thunk extra arg somehow?
+  D extends Dispatch<AnyAction> = ThunkDispatch<S, unknown, AnyAction>,
+  ExtraArgument = unknown
+>(middlewareOptions: CreateListenerMiddlewareOptions<ExtraArgument> = {}) {
   type ListenerEntry = ActionListenerOptions & {
     id: string
     listener: ActionListener<any, S, D, any>
@@ -212,6 +221,7 @@ export function createActionListenerMiddleware<
   }
 
   const listenerMap = new Map<string, ListenerEntry>()
+  const { extra } = middlewareOptions
 
   const middleware: Middleware<
     {
@@ -253,10 +263,11 @@ export function createActionListenerMiddleware<
           entry.listener(action, {
             ...api,
             currentPhase,
+            extra,
             unsubscribe: entry.unsubscribe,
           })
         } catch (err) {
-          // ignore
+          // ignore errors deliberately
         }
       }
       if (currentPhase === 'beforeReducer') {

packages/action-listener-middleware/src/tests/listenerMiddleware.test.ts

@@ -45,6 +45,30 @@ describe('createActionListenerMiddleware', () => {
     })
   })
 
+  test('Allows passing an extra argument on middleware creation', () => {
+    const originalExtra = 42
+    middleware = createActionListenerMiddleware({
+      extra: originalExtra,
+    })
+    reducer = jest.fn(() => ({}))
+    store = configureStore({
+      reducer,
+      middleware: [middleware] as const,
+    })
+
+    let foundExtra = null
+
+    middleware.addListener(
+      (action: AnyAction) => true,
+      (action, listenerApi) => {
+        foundExtra = listenerApi.extra
+      }
+    )
+
+    store.dispatch(testAction1('a'))
+    expect(foundExtra).toBe(originalExtra)
+  })
+
   test('directly subscribing', () => {
     const listener = jest.fn((_: TestAction1) => {})