[PLAT-9731] Fix XHR delivery postReportCallback

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Changes
 
 - (react-native) Update bugsnag-android from v5.28.3 to [v5.28.4](https://github.com/bugsnag/bugsnag-android/blob/master/CHANGELOG.md#5284-2023-02-08)
+- (delivery-xml-http-request) Ensure delivery errors are passed to the post report callback [#1938](https://github.com/bugsnag/bugsnag-js/pull/1938)
 
 ## 7.20.1 (2023-02-08)
 

packages/delivery-xml-http-request/delivery.js

@@ -1,5 +1,14 @@
 const payload = require('@bugsnag/core/lib/json-payload')
 
+function deliveryFailed (client, body, cb) {
+  const err = new Error('Event failed to send')
+  client._logger.error('Event failed to send…', err)
+  if (body.length > 10e5) {
+    client._logger.warn(`Event oversized (${(body.length / 10e5).toFixed(2)} MB)`)
+  }
+  cb(err)
+}
+
 module.exports = (client, win = window) => ({
   sendEvent: (event, cb = () => {}) => {
     try {
@@ -11,14 +20,17 @@ module.exports = (client, win = window) => ({
         if (req.readyState === win.XMLHttpRequest.DONE) {
           const status = req.status
           if (status === 0 || status >= 400) {
-            client._logger.error('Event failed to send…')
-            if (body.length > 10e5) {
-              client._logger.warn(`Event oversized (${(body.length / 10e5).toFixed(2)} MB)`)
-            }
+            deliveryFailed(client, body, cb)
+          } else {
+            cb(null)
           }
-          cb(null)
         }
       }
+
+      req.onerror = function () {
+        deliveryFailed(client, body, cb)
+      }
+
       req.open('POST', url)
       req.setRequestHeader('Content-Type', 'application/json')
       req.setRequestHeader('Bugsnag-Api-Key', event.apiKey || client._config.apiKey)

packages/delivery-xml-http-request/test/delivery.test.ts

@@ -58,6 +58,50 @@ describe('delivery:XMLHttpRequest', () => {
     })
   })
 
+  it('calls back with an error when report sending fails', done => {
+    const requests: MockXMLHttpRequest[] = []
+
+    // mock XMLHttpRequest class
+    function XMLHttpRequest (this: MockXMLHttpRequest) {
+      this.method = null
+      this.url = null
+      this.data = null
+      this.headers = {}
+      this.readyState = null
+      this.status = 0
+      requests.push(this)
+    }
+    XMLHttpRequest.DONE = 4
+    XMLHttpRequest.prototype.open = function (method: string, url: string) {
+      this.method = method
+      this.url = url
+    }
+    XMLHttpRequest.prototype.setRequestHeader = function (key: string, val: string) {
+      this.headers[key] = val
+    }
+    XMLHttpRequest.prototype.send = function (data: string) {
+      this.data = data
+      this.readyState = XMLHttpRequest.DONE
+      this.status = 500 // server error
+      this.onreadystatechange()
+    }
+
+    const logger = { error: jest.fn(), warn: jest.fn() }
+    const payload = { events: [] } as unknown as EventDeliveryPayload
+    const config = {
+      apiKey: 'aaaaaaaa',
+      endpoints: { notify: '/echo/' },
+      redactedKeys: []
+    }
+
+    delivery({ _logger: logger, _config: config } as unknown as Client, { XMLHttpRequest } as unknown as Window).sendEvent(payload, (err: any) => {
+      const expectedError = new Error('Event failed to send')
+      expect(err).toStrictEqual(expectedError)
+      expect(logger.error).toHaveBeenCalledWith('Event failed to send…', expectedError)
+      done()
+    })
+  })
+
   it('logs failures and large payloads', done => {
     const requests: MockXMLHttpRequest[] = []
 
@@ -101,8 +145,9 @@ describe('delivery:XMLHttpRequest', () => {
     const logger = { error: jest.fn(), warn: jest.fn() }
 
     delivery({ _logger: logger, _config: config } as unknown as Client, { XMLHttpRequest } as unknown as Window).sendEvent(payload, (err: any) => {
-      expect(err).toBe(null)
-      expect(logger.error).toHaveBeenCalledWith('Event failed to send…')
+      const expectedError = new Error('Event failed to send')
+      expect(err).toStrictEqual(expectedError)
+      expect(logger.error).toHaveBeenCalledWith('Event failed to send…', expectedError)
       expect(logger.warn).toHaveBeenCalledWith('Event oversized (1.01 MB)')
       done()
     })