[enhance] Warn when fetch actions reach reducer

src/state/__tests__/reducer.ts

@@ -271,7 +271,8 @@ describe('reducer', () => {
     const newState = reducer(iniState, action);
     expect(newState).toEqual(iniState);
   });
-  it('other types should do nothing', () => {
+  it('rest-hooks/fetch should console.warn()', () => {
+    global.console.warn = jest.fn();
     const action: FetchAction = {
       type: 'rest-hooks/fetch',
       payload: () => new Promise<any>(() => null),
@@ -291,5 +292,18 @@ describe('reducer', () => {
     };
     const newState = reducer(iniState, action);
     expect(newState).toBe(iniState);
+    expect((global.console.warn as jest.Mock).mock.calls.length).toBe(2);
+  });
+  it('other types should do nothing', () => {
+    const action: any = {
+      type: 'whatever',
+    };
+    const iniState = {
+      entities: {},
+      results: { abc: '5' },
+      meta: {},
+    };
+    const newState = reducer(iniState, action);
+    expect(newState).toBe(iniState);
   });
 });

src/state/reducer.ts

@@ -98,6 +98,11 @@ export default function reducer(state: State<unknown> | undefined, action: Actio
       entities: e,
     };
   default:
+    // If 'fetch' action reaches the reducer there are no middlewares installed to handle it
+    if (process.env.NODE_ENV !== 'production' && action.type === 'rest-hooks/fetch') {
+      console.warn('Reducer recieved fetch action - you are likely missing the NetworkManager middleware')
+      console.warn('See https://resthooks.io/docs/guides/redux#indextsx for hooking up redux')
+    }
     // A reducer must always return a valid state.
     // Alternatively you can throw an error if an invalid action is dispatched.
     return state;