Handle request retry or re-routing in middleware.afterFilters

src/middleware-stack.ts

@@ -1,5 +1,9 @@
 export type BeforeFilter = (requestUrl: string, options: RequestInit) => void
-export type AfterFilter = (response: Response, json: JSON) => void
+export type AfterFilter = (
+  response: Response,
+  json: JSON,
+  requestOptions: RequestInit
+) => void
 
 async function asyncForEach(array: Array<Function>, callback: Function) {
   for (let index = 0; index < array.length; index += 1) {
@@ -10,10 +14,12 @@ async function asyncForEach(array: Array<Function>, callback: Function) {
 export class MiddlewareStack {
   private _beforeFilters: BeforeFilter[] = []
   private _afterFilters: AfterFilter[] = []
+  public newResponse: Response | null = null
 
   constructor(before: BeforeFilter[] = [], after: AfterFilter[] = []) {
     this._beforeFilters = before
     this._afterFilters = after
+    this.newResponse = null
   }
 
   get beforeFilters() {
@@ -30,9 +36,13 @@ export class MiddlewareStack {
     })
   }
 
-  async afterFetch(response: Response, json: JSON) {
+  async afterFetch(
+    response: Response,
+    json: JSON,
+    requestOptions: RequestInit
+  ) {
     await asyncForEach(this._afterFilters, async (filter: Function) => {
-      await filter(response, json)
+      await filter(response, json, requestOptions)
     })
   }
 }

src/request.ts

@@ -109,9 +109,9 @@ export class Request {
       throw new ResponseError(null, e.message, e)
     }
 
-    await this._handleResponse(response, options)
+    const middlewareResponse = await this._handleResponse(response, options)
 
-    return response
+    return middlewareResponse || response
   }
 
   private async _handleResponse(
@@ -133,7 +133,13 @@ export class Request {
     }
 
     try {
-      await this.middleware.afterFetch(response, json)
+      await this.middleware.afterFetch(response, json, requestOptions)
+
+      if (this.middleware.newResponse) {
+        response = this.middleware.newResponse.clone()
+        json = await response.json()
+        this.middleware.newResponse = null
+      }
     } catch (e) {
       // afterFetch middleware failed
       throw new ResponseError(
@@ -156,6 +162,8 @@ export class Request {
     }
 
     ;(<any>response).jsonPayload = json
+
+    return response
   }
 }