fix: Exclude data url requests as captured AJAX events

src/common/deny-list/deny-list.js

@@ -10,14 +10,9 @@ var denyList = []
  * @returns {boolean} `true` if request does not match any entries of {@link denyList|deny list}; else `false`
  */
 export function shouldCollectEvent (params) {
-  if (denyList.length === 0) {
-    return true
-  }
+  if (hasUndefinedHostname(params)) return false
 
-  // XHR requests with an undefined hostname (e.g., data URLs) should not be collected.
-  if (params.hostname === undefined) {
-    return false
-  }
+  if (denyList.length === 0) return true
 
   for (var i = 0; i < denyList.length; i++) {
     var parsed = denyList[i]
@@ -35,6 +30,10 @@ export function shouldCollectEvent (params) {
   return true
 }
 
+export function hasUndefinedHostname (params) {
+  return (params.hostname === undefined) // requests with an undefined hostname (e.g., data URLs) should not be collected.
+}
+
 /**
  * Initializes the {@link denyList|XHR deny list} by extracting hostname and pathname from an array of filter strings.
  * @param {string[]} denyListConfig - array of URL filters to identify XHR requests to be excluded from collection

src/features/ajax/instrument/index.js

@@ -17,6 +17,7 @@ import { FEATURE_NAME } from '../constants'
 import { FEATURE_NAMES } from '../../../loaders/features/features'
 import { SUPPORTABILITY_METRIC } from '../../metrics/constants'
 import { now } from '../../../common/timing/now'
+import { hasUndefinedHostname } from '../../../common/deny-list/deny-list'
 
 var handlers = ['load', 'error', 'abort', 'timeout']
 var handlersLen = handlers.length
@@ -338,18 +339,18 @@ function subscribeToEvents (agentIdentifier, ee, handler, dt) {
   // eslint-disable-next-line handle-callback-err
   function onFetchDone (_, res) {
     this.endTime = now()
-    if (!this.params) {
-      this.params = {}
-    }
+    if (!this.params) this.params = {}
+    if (hasUndefinedHostname(this.params)) return // don't bother with fetch to url with no hostname
+
     this.params.status = res ? res.status : 0
 
     // convert rxSize to a number
-    var responseSize
+    let responseSize
     if (typeof this.rxSize === 'string' && this.rxSize.length > 0) {
       responseSize = +this.rxSize
     }
 
-    var metrics = {
+    const metrics = {
       txSize: this.txSize,
       rxSize: responseSize,
       duration: now() - this.startTime
@@ -360,17 +361,18 @@ function subscribeToEvents (agentIdentifier, ee, handler, dt) {
 
   // Create report for XHR request that has finished
   function end (xhr) {
-    var params = this.params
-    var metrics = this.metrics
-
+    const params = this.params
+    const metrics = this.metrics
     if (this.ended) return
     this.ended = true
 
-    for (var i = 0; i < handlersLen; i++) {
+    for (let i = 0; i < handlersLen; i++) {
       xhr.removeEventListener(handlers[i], this.listener, false)
     }
 
     if (params.aborted) return
+    if (hasUndefinedHostname(params)) return // don't bother with XHR of url with no hostname
+
     metrics.duration = now() - this.startTime
     if (!this.loadCaptureCalled && xhr.readyState === 4) {
       captureXhrData(this, xhr)

tests/components/ajax/instrument.test.js

@@ -21,7 +21,7 @@ beforeAll(() => {
   baseEE = ajaxInstrument.ee
 })
 
-describe('Data url DOES generates telemetry for', () => {
+describe('Ajax event is not captured or buffered for data urls', () => {
   let xhrEventLogged
   beforeAll(() => { baseEE.on('xhr', monitorXhrEvent) })
   beforeEach(() => { xhrEventLogged = false })
@@ -37,7 +37,7 @@ describe('Data url DOES generates telemetry for', () => {
     xhr.onreadystatechange = function () {
       if (xhr.readyState === XMLHttpRequest.DONE) {
         setTimeout(() => { // the following has to wait for next loop so monitorXhrEvent can run
-          expect(xhrEventLogged).toEqual(true)
+          expect(xhrEventLogged).toEqual(false)
           baseEE.removeEventListener('send-xhr-start', validateIsDataProtocol)
           done()
         }, 0)
@@ -50,7 +50,7 @@ describe('Data url DOES generates telemetry for', () => {
     baseEE.on('fetch-done', validateIsDataProtocol)
 
     fetch('data:,dataUrl').then(() => {
-      expect(xhrEventLogged).toEqual(true)
+      expect(xhrEventLogged).toEqual(false)
       baseEE.removeEventListener('fetch-done', validateIsDataProtocol)
       done()
     })

tests/specs/ajax/deny-list.e2e.js

@@ -75,4 +75,22 @@ describe('xhr events deny list', () => {
       })
     ]))
   })
+
+  it.withBrowsersMatching(supportsFetch)('does not capture data URLs (or events with undefined hostname) at all', async () => {
+    const url = await browser.testHandle.assetURL('instrumented.html') // has no deny list
+    await browser.url(url).then(() => browser.waitForAgentLoad())
+
+    const [ajaxEvents, ajaxMetrics] = await Promise.all([
+      browser.testHandle.expectAjaxEvents(),
+      browser.testHandle.expectAjaxTimeSlices(),
+      browser.execute(function () {
+        fetch('data:,Hello%2C%20World%21')
+      })
+    ])
+
+    const undefinedDomainEvt = ajaxEvents.request.body.find(obj => obj.domain.startsWith('undefined'))
+    expect(undefinedDomainEvt).toBeUndefined()
+    const undefinedHostMetric = ajaxMetrics.request.body.xhr.find(obj => obj.params.host.startsWith('undefined'))
+    expect(undefinedHostMetric).toBeUndefined()
+  })
 })

tests/specs/ajax/fetch.e2e.js

@@ -200,77 +200,6 @@ describe.withBrowsersMatching(supportsFetch)('Fetch Ajax', () => {
     })
   })
 
-  it('creates event and metric data for fetch using data uri', async () => {
-    await browser.url(await browser.testHandle.assetURL('ajax/fetch-data-uri.html'))
-      .then(() => browser.waitForAgentLoad())
-
-    const [ajaxEventsHarvest, ajaxTimeSlicesHarvest] = await Promise.all([
-      browser.testHandle.expectAjaxEvents(),
-      browser.testHandle.expectAjaxTimeSlices(),
-      browser.execute(function () {
-        // We don't want the spa feature to pick up the ajax call
-        window.disableAjaxHashChange = true
-      }).then(() => $('#sendAjax').click())
-    ])
-
-    const ajaxEvent = ajaxEventsHarvest.request.body.find(event => event.domain === 'undefined:undefined')
-    expect(ajaxEvent).toEqual({
-      type: 'ajax',
-      children: [],
-      start: expect.toBeWithin(1, Infinity),
-      end: expect.toBeWithin(1, Infinity),
-      callbackEnd: expect.toBeWithin(1, Infinity),
-      callbackDuration: 0,
-      method: 'GET',
-      status: 200,
-      domain: 'undefined:undefined',
-      path: '',
-      requestBodySize: 0,
-      // Only firefox captures the data response size
-      responseBodySize: browserMatch(onlyFirefox) ? 8 : 0,
-      requestedWith: 'fetch',
-      nodeId: '0',
-      guid: null,
-      traceId: null,
-      timestamp: null
-    })
-
-    const ajaxMetric = ajaxTimeSlicesHarvest.request.body.xhr.find(metric => metric.params.host === 'undefined:undefined')
-    expect(ajaxMetric).toEqual({
-      params: {
-        protocol: 'data',
-        host: 'undefined:undefined',
-        method: 'GET',
-        status: 200
-      },
-      metrics: {
-        count: 1,
-        duration: {
-          t: expect.toBeWithin(0, Infinity)
-        },
-        // Only firefox captures the data response size
-        ...(browserMatch(onlyFirefox)
-          ? {
-              rxSize: {
-                t: 8
-              }
-            }
-          : {
-              rxSize: {
-                c: 1
-              }
-            }
-        ),
-        time: {
-          t: expect.toBeWithin(1, Infinity)
-        },
-        txSize: {
-          t: 0
-        }
-      }
-    })
-  })
-
   ;[
     { title: 'promise resolved callbacks', url: 'ajax/fetch-promise-resolve.html' },
     { title: 'promise rejected callbacks', url: 'ajax/fetch-promise-reject.html' },

tests/specs/ajax/xhr.e2e.js

@@ -1,4 +1,4 @@
-import { notIE, onlyFirefox } from '../../../tools/browser-matcher/common-matchers.mjs'
+import { onlyFirefox } from '../../../tools/browser-matcher/common-matchers.mjs'
 
 describe('XHR Ajax', () => {
   it('creates event and metric data for xhr', async () => {
@@ -196,66 +196,6 @@ describe('XHR Ajax', () => {
     })
   })
 
-  it.withBrowsersMatching(notIE)('creates event and metric data for xhr using data uri', async () => {
-    await browser.url(await browser.testHandle.assetURL('ajax/xhr-data-uri.html'))
-      .then(() => browser.waitForAgentLoad())
-
-    const [ajaxEventsHarvest, ajaxTimeSlicesHarvest] = await Promise.all([
-      browser.testHandle.expectAjaxEvents(),
-      browser.testHandle.expectAjaxTimeSlices(),
-      browser.execute(function () {
-        // We don't want the spa feature to pick up the ajax call
-        window.disableAjaxHashChange = true
-      }).then(() => $('#sendAjax').click())
-    ])
-
-    const ajaxEvent = ajaxEventsHarvest.request.body.find(event => event.domain === 'undefined:undefined')
-    expect(ajaxEvent).toEqual({
-      type: 'ajax',
-      children: [],
-      start: expect.toBeWithin(1, Infinity),
-      end: expect.toBeWithin(1, Infinity),
-      callbackEnd: expect.toBeWithin(1, Infinity),
-      callbackDuration: 0,
-      method: 'GET',
-      status: 200,
-      domain: 'undefined:undefined',
-      path: '',
-      requestBodySize: 0,
-      responseBodySize: 8,
-      requestedWith: 'XMLHttpRequest',
-      nodeId: '0',
-      guid: null,
-      traceId: null,
-      timestamp: null
-    })
-
-    const ajaxMetric = ajaxTimeSlicesHarvest.request.body.xhr.find(metric => metric.params.host === 'undefined:undefined')
-    expect(ajaxMetric).toEqual({
-      params: {
-        protocol: 'data',
-        host: 'undefined:undefined',
-        method: 'GET',
-        status: 200
-      },
-      metrics: {
-        cbTime: {
-          t: expect.toBeWithin(75, 126)
-        },
-        count: 1,
-        duration: {
-          t: expect.toBeWithin(0, Infinity)
-        },
-        rxSize: {
-          t: 8
-        },
-        time: {
-          t: expect.toBeWithin(1, Infinity)
-        }
-      }
-    })
-  })
-
   it('only includes load handlers in metric timings', async () => {
     await browser.url(await browser.testHandle.assetURL('ajax/xhr-callback-duration.html'))
       .then(() => browser.waitForAgentLoad())