Changes from review

packages/driver/cypress/integration/commands/net_stubbing_spec.ts

@@ -271,9 +271,17 @@ describe('network stubbing', { retries: { runMode: 2, openMode: 0 } }, function
         cy
         .intercept('/dump-headers', { middleware: true }, (req) => {
           e.push('mware req handler')
-          req.on('before:response', (res) => e.push('mware before:response'))
-          req.on('response', (res) => e.push('mware response'))
-          req.on('after:response', (res) => e.push('mware after:response'))
+          req.on('before:response', (res) => {
+            e.push('mware before:response')
+          })
+
+          req.on('response', (res) => {
+            e.push('mware response')
+          })
+
+          req.on('after:response', (res) => {
+            e.push('mware after:response')
+          })
         })
         .intercept('/dump-headers', (req) => {
           e.push('normal req handler')
@@ -1275,23 +1283,6 @@ describe('network stubbing', { retries: { runMode: 2, openMode: 0 } }, function
     })
 
     context('request events', function () {
-      it('receives response error in `error`', function () {
-        let err
-
-        cy.intercept({ hostname: 'foo.invalid' }, (req) => {
-          req.on('error', (_err) => {
-            err = _err
-          })
-        }).as('err')
-        .then(() => {
-          $.get('http://foo.invalid')
-        })
-        .wait('@err')
-        .then(() => {
-          expect(err.message).to.contain('ENOTFOUND')
-        })
-      })
-
       context('can end response', () => {
         for (const eventName of ['before:response', 'response']) {
           it(`in \`${eventName}\``, () => {

packages/driver/src/cy/net-stubbing/events/before-request.ts

@@ -22,7 +22,7 @@ const debug = Debug('cypress:driver:net-stubbing:events:before-request')
 
 type Result = HandlerResult<CyHttpMessages.IncomingRequest>
 
-const validEvents = ['before:response', 'response', 'after:response', 'error']
+const validEvents = ['before:response', 'response', 'after:response']
 
 export const onBeforeRequest: HandlerFn<CyHttpMessages.IncomingRequest> = (Cypress, frame, userHandler, { getRoute, getRequest, emitNetEvent, sendStaticResponse }) => {
   function getRequestLog (route: Route, request: Omit<Interception, 'log'>) {
@@ -59,6 +59,24 @@ export const onBeforeRequest: HandlerFn<CyHttpMessages.IncomingRequest> = (Cypre
 
   parseJsonBody(req)
 
+  const subscribe = (eventName, handler) => {
+    const subscription: Subscription = {
+      id: _.uniqueId('Subscription'),
+      routeId,
+      eventName,
+      await: true,
+    }
+
+    request.subscriptions.push({
+      subscription,
+      handler,
+    })
+
+    debug('created request subscription %o', { eventName, request, subscription, handler })
+
+    emitNetEvent('subscribe', { requestId, subscription } as NetEvent.ToServer.Subscribe)
+  }
+
   const getCanonicalRequest = (): Interception => {
     const existingRequest = getRequest(routeId, requestId)
 
@@ -90,21 +108,7 @@ export const onBeforeRequest: HandlerFn<CyHttpMessages.IncomingRequest> = (Cypre
           return $errUtils.throwErrByPath('net_stubbing.request_handling.event_needs_handler')
         }
 
-        const subscription: Subscription = {
-          id: _.uniqueId('Subscription'),
-          routeId,
-          eventName,
-          await: true,
-        }
-
-        request.subscriptions.push({
-          subscription,
-          handler,
-        })
-
-        debug('created request subscription %o', { eventName, request, subscription, handler })
-
-        emitNetEvent('subscribe', { requestId, subscription } as NetEvent.ToServer.Subscribe)
+        subscribe(eventName, handler)
 
         return request
       },
@@ -139,7 +143,7 @@ export const onBeforeRequest: HandlerFn<CyHttpMessages.IncomingRequest> = (Cypre
       }
 
       // allow `req` to be sent outgoing, then pass the response body to `responseHandler`
-      request.on('before:response', responseHandler)
+      subscribe('response:callback', responseHandler)
 
       userReq.responseTimeout = userReq.responseTimeout || Cypress.config('responseTimeout')
 

packages/driver/src/cy/net-stubbing/events/index.ts

@@ -2,7 +2,7 @@ import { Route, Interception, StaticResponse, NetEvent } from '../types'
 import { onBeforeRequest } from './before-request'
 import { onResponse } from './response'
 import { onAfterResponse } from './after-response'
-import { onError } from './error'
+import { onNetworkError } from './network-error'
 import Bluebird from 'bluebird'
 import { getBackendStaticResponse } from '../static-response-utils'
 
@@ -21,9 +21,10 @@ export type HandlerFn<D> = (Cypress: Cypress.Cypress, frame: NetEvent.ToDriver.E
 const netEventHandlers: { [eventName: string]: HandlerFn<any> } = {
   'before:request': onBeforeRequest,
   'before:response': onResponse,
+  'response:callback': onResponse,
   'response': onResponse,
   'after:response': onAfterResponse,
-  'error': onError,
+  'network:error': onNetworkError,
 }
 
 export function registerEvents (Cypress: Cypress.Cypress, cy: Cypress.cy) {

packages/driver/src/cy/net-stubbing/events/error.ts → packages/driver/src/cy/net-stubbing/events/network-error.ts

@@ -3,7 +3,7 @@ import { CyHttpMessages } from '@packages/net-stubbing/lib/types'
 import { errByPath, makeErrFromObj } from '../../../cypress/error_utils'
 import { HandlerFn } from '.'
 
-export const onError: HandlerFn<CyHttpMessages.Error> = async (Cypress, frame, userHandler, { getRequest, getRoute }) => {
+export const onNetworkError: HandlerFn<CyHttpMessages.NetworkError> = async (Cypress, frame, userHandler, { getRequest, getRoute }) => {
   const request = getRequest(frame.subscription.routeId, frame.requestId)
 
   const { data } = frame
@@ -13,9 +13,9 @@ export const onError: HandlerFn<CyHttpMessages.Error> = async (Cypress, frame, u
   }
 
   let err = makeErrFromObj(data.error)
-  // does this request have a `before:response` handler?
+  // does this request have a user response callback handler?
   const hasResponseHandler = !!request.subscriptions.find(({ subscription }) => {
-    return subscription.eventName === 'before:response'
+    return subscription.eventName === 'response:callback'
   })
   const isAwaitingResponse = hasResponseHandler && ['Received', 'Intercepted'].includes(request.state)
   const isTimeoutError = data.error.code && ['ESOCKETTIMEDOUT', 'ETIMEDOUT'].includes(data.error.code)

packages/net-stubbing/lib/external-types.ts

@@ -157,7 +157,7 @@ export namespace CyHttpMessages {
     finalResBody?: BaseMessage['body']
   }
 
-  export interface Error {
+  export interface NetworkError {
     error: any
   }
 }
@@ -206,28 +206,23 @@ export interface Subscription {
 
 interface InterceptionEvents {
   /**
-   * Emitted before `response` and at the same time as `req.continue` and `req.reply` handlers.
+   * Emitted before `response` and before any `req.continue` handlers.
    * Modifications to `res` will be applied to the incoming response.
    * If a promise is returned from `cb`, it will be awaited before processing other event handlers.
    */
-  on(eventName: 'before:response', cb: (res: CyHttpMessages.IncomingHttpResponse) => void): Interception
+  on(eventName: 'before:response', cb: HttpResponseInterceptor): Interception
   /**
-   * Emitted after `before:response` and after any `req.continue` or `req.reply` handlers - before the response is sent to the browser.
+   * Emitted after `before:response` and after any `req.continue` handlers - before the response is sent to the browser.
    * Modifications to `res` will be applied to the incoming response.
    * If a promise is returned from `cb`, it will be awaited before processing other event handlers.
    */
-  on(eventName: 'response', cb: (res: CyHttpMessages.IncomingHttpResponse) => void): Interception
+  on(eventName: 'response', cb: HttpResponseInterceptor): Interception
   /**
    * Emitted once the response to a request has finished sending to the browser.
    * Modifications to `res` have no impact.
    * If a promise is returned from `cb`, it will be awaited before processing other event handlers.
    */
-  on(eventName: 'after:response', cb: (res: CyHttpMessages.IncomingResponse) => void): Interception
-    /**
-   * Emitted when a network error is encountered during an upstream request.
-   * If a promise is returned from `cb`, it will be awaited before processing other event handlers.
-   */
-  on(eventName: 'error', cb: (err: Error) => void): Interception
+  on(eventName: 'after:response', cb: (res: CyHttpMessages.IncomingResponse) => void | Promise<void>): Interception
 }
 
 /**
@@ -445,7 +440,7 @@ declare global {
        *    })
        * @example
        *    cy.intercept('https://localhost:7777/some-response', (req) => {
-       *      req.reply(res => {
+       *      req.continue(res => {
        *        res.body = 'some new body'
        *      })
        *    })

packages/net-stubbing/lib/server/driver-events.ts

@@ -63,7 +63,7 @@ async function sendStaticResponse (state: NetStubbingState, getFixture: GetFixtu
     return
   }
 
-  if (options.staticResponse.fixture && ['before:response', 'response'].includes(request.lastEvent!)) {
+  if (options.staticResponse.fixture && ['before:response', 'response:callback', 'response'].includes(request.lastEvent!)) {
     // if we're already in a response phase, it's possible that the fixture body will never be sent to the browser
     // so include the fixture body in `after:response`
     request.includeBodyInAfterResponse = true

packages/net-stubbing/lib/server/intercepted-request.ts

@@ -68,11 +68,10 @@ export class InterceptedRequest {
         immediateStaticResponse: route.staticResponse,
         subscriptions: [{
           eventName: 'before:request',
-          // req.reply callback?
           await: !!route.hasInterceptor,
           routeId: route.id,
         },
-        ...(['before:response', 'after:response', 'error'].map((eventName) => {
+        ...(['response:callback', 'after:response', 'network:error'].map((eventName) => {
           // notification-only default event
           return { eventName, await: false, routeId: route.id }
         }))],

packages/net-stubbing/lib/server/middleware/error.ts

@@ -19,8 +19,8 @@ export const InterceptError: ErrorMiddleware = async function () {
 
   request.continueResponse = this.next
 
-  await request.handleSubscriptions<CyHttpMessages.Error>({
-    eventName: 'error',
+  await request.handleSubscriptions<CyHttpMessages.NetworkError>({
+    eventName: 'network:error',
     data: {
       error: errors.clone(this.error),
     },

packages/net-stubbing/lib/server/middleware/response.ts

@@ -73,7 +73,7 @@ export const InterceptResponse: ResponseMiddleware = async function () {
   }
 
   const modifiedRes = await request.handleSubscriptions<CyHttpMessages.IncomingResponse>({
-    eventName: ['before:response', 'response'],
+    eventName: ['before:response', 'response:callback', 'response'],
     data: res,
     mergeChanges,
   })

packages/runner/cypress/fixtures/errors/intercept_spec.ts

@@ -73,7 +73,7 @@ describe('cy.intercept', () => {
         data: {},
       })
 
-      Cypress.emit('net:event', 'error', {
+      Cypress.emit('net:event', 'network:error', {
         eventId: '1',
         requestId: '1',
         subscription: {