Return error tuples for more reliable responses

package.json

@@ -13,7 +13,8 @@
     "prettier-check": "./scripts/prettier-check",
     "prettier": "prettier --write \"{src,tests,types,examples,docs}/**/*.{ts,tsx,js,jsx}\"",
     "tests": "jest",
-    "test": "npm run lint && npm run tests -- --runInBand --coverage",
+    "typecheck": "tsc --project tsconfig.json --noEmit",
+    "test": "npm run typecheck && npm run lint && npm run tests -- --runInBand --coverage",
     "prepublishOnly": "npm test && npm run dist"
   },
   "repository": {

src/ts/actions.ts

@@ -3,6 +3,7 @@ import { Dispatch } from 'redux';
 import {
   AsyncActionSet,
   Dict,
+  ErrorOrResponse,
   ExtraMeta,
   Options,
   RequestParams,
@@ -53,7 +54,7 @@ export function requestWithConfig(
   options: Options = {},
   extraMeta: Partial<ExtraMeta> = {}
 ) {
-  return (dispatch: Dispatch<any>) => {
+  return (dispatch: Dispatch<any>): Promise<ErrorOrResponse> => {
     const meta = serializeMeta(extraMeta, options);
 
     dispatch({ type: actionSet.REQUEST, meta });
@@ -67,7 +68,7 @@ export function requestWithConfig(
           meta,
         });
         dispatch(setRequestState(actionSet, 'SUCCESS', response, meta.tag));
-        return response;
+        return Promise.resolve([null, response] as ErrorOrResponse);
       },
       (error: AxiosError) => {
         const { shouldRethrow } = options;
@@ -81,10 +82,10 @@ export function requestWithConfig(
         dispatch(setRequestState(actionSet, 'FAILURE', error, meta.tag));
 
         if (shouldRethrow && shouldRethrow(error)) {
-          return Promise.reject(error);
+          return Promise.reject([error, null] as ErrorOrResponse);
         }
 
-        return Promise.resolve();
+        return Promise.resolve([error, null] as ErrorOrResponse);
       }
     );
   };

src/ts/types.ts

@@ -40,3 +40,5 @@ export interface RequestParams extends Options {
   readonly metaData?: ExtraMeta;
   readonly headers?: Dict<string>;
 }
+
+export type ErrorOrResponse = [(AxiosError | null), (AxiosResponse | null)];

tests/index.ts

@@ -167,6 +167,7 @@ describe('Requests', () => {
       it('should return a thunk for sending a generic request', () => {
         expect(typeof thunk).toBe('function');
       });
+
       it('should dispatch request actions', () => {
         myRequest = (thunk(dispatch) as any) as AxiosMock; // FIXME: We need type-safe mocking
 
@@ -198,7 +199,7 @@ describe('Requests', () => {
 
       it('should dispatch success actions', () => {
         myRequest = (thunk(dispatch) as any) as AxiosMock;
-        myRequest.success({
+        const result = myRequest.success({
           data: 'llama',
         });
 
@@ -213,6 +214,10 @@ describe('Requests', () => {
         expect(dispatch).toHaveBeenCalledWith(
           setRequestState(ACTION_SET, 'SUCCESS', { data: 'llama' }, undefined)
         );
+
+        return result.then((data: any) => {
+          expect(data).toEqual([null, { data: 'llama' }]);
+        });
       });
 
       it('should dispatch failure actions', () => {
@@ -245,7 +250,7 @@ describe('Requests', () => {
           )
         );
         return result.then((data: any) => {
-          expect(data).toBeUndefined();
+          expect(data).toEqual([{ response: { data: 'llama' } }, null]);
         });
       });
 
@@ -264,7 +269,7 @@ describe('Requests', () => {
             },
           })
           .catch((error: any) => {
-            expect(error).toEqual({ response: { data: 'llama' } });
+            expect(error).toEqual([{ response: { data: 'llama' } }, null]);
           });
       });
     });