feat(interceptors): provide Request to response interceptors

closes #33

Author: timbell

src/http-client.js

@@ -105,12 +105,13 @@ export class HttpClient {
         if (Response.prototype.isPrototypeOf(result)) {
           response = result;
         } else if (Request.prototype.isPrototypeOf(result)) {
+          request = Promise.resolve(result);
           response = fetch(result);
         } else {
           throw new Error(`An invalid result was returned by the interceptor chain. Expected a Request or Response instance, but got [${result}]`);
         }
 
-        return processResponse(response, this.interceptors);
+        return request.then(_request => processResponse(response, this.interceptors, _request));
       });
 
     return this::trackRequestEndWith(promise);
@@ -191,18 +192,18 @@ function processRequest(request, interceptors) {
   return applyInterceptors(request, interceptors, 'request', 'requestError');
 }
 
-function processResponse(response, interceptors) {
-  return applyInterceptors(response, interceptors, 'response', 'responseError');
+function processResponse(response, interceptors, request) {
+  return applyInterceptors(response, interceptors, 'response', 'responseError', request);
 }
 
-function applyInterceptors(input, interceptors, successName, errorName) {
+function applyInterceptors(input, interceptors, successName, errorName, ...interceptorArgs) {
   return (interceptors || [])
     .reduce((chain, interceptor) => {
       let successHandler = interceptor[successName];
       let errorHandler = interceptor[errorName];
 
       return chain.then(
-        successHandler && interceptor::successHandler,
-        errorHandler && interceptor::errorHandler);
+        successHandler && (value => interceptor::successHandler(value, ...interceptorArgs)),
+        errorHandler && (reason => interceptor::errorHandler(reason, ...interceptorArgs)));
     }, Promise.resolve(input));
 }

src/interfaces.js

@@ -29,7 +29,7 @@ interface Interceptor {
   *
   * @param response - The response.
   */
-  response?: (response: Response) => Response|Promise<Response>;
+  response?: (response: Response, request?: Request) => Response|Promise<Response>;
 
   /**
    * Handles fetch errors and errors generated by previous interceptors. This
@@ -39,7 +39,7 @@ interface Interceptor {
    * @param error - The rejection value from the fetch request or from a
    * previous interceptor.
    */
-  responseError?: (error: any) => Response|Promise<Response>;
+  responseError?: (error: any, request?: Request) => Response|Promise<Response>;
 }
 
 /**

test/http-client.spec.js

@@ -172,7 +172,7 @@ describe('HttpClient', () => {
 
       client.fetch('path')
         .then(() => {
-          expect(interceptor.response).toHaveBeenCalledWith(jasmine.any(Response));
+          expect(interceptor.response).toHaveBeenCalledWith(jasmine.any(Response), jasmine.any(Request));
           expect(interceptor.responseError).not.toHaveBeenCalled();
           done();
         });
@@ -189,7 +189,7 @@ describe('HttpClient', () => {
       client.fetch('path')
         .catch(() => {
           expect(interceptor.response).not.toHaveBeenCalled();
-          expect(interceptor.responseError).toHaveBeenCalledWith(jasmine.any(Response));
+          expect(interceptor.responseError).toHaveBeenCalledWith(jasmine.any(Response), jasmine.any(Request));
           done();
         });
     });