fix(rum-core): ensure apmRequest is called for events (#1055)

* fix(rum-core): ensure apmRequest is called for events

* chore: fix cors and tests

* chore: allow headers from apm server

dev-utils/docker-compose.yml

@@ -43,6 +43,7 @@ services:
       apm-server -e
         -E apm-server.rum.enabled=true
         -E apm-server.rum.event_rate.limit=100000
+        -E apm-server.rum.allow_headers=["x-custom-header"]
         -E apm-server.host=0.0.0.0:8200
         -E apm-server.read_timeout=1m
         -E apm-server.shutdown_timeout=2m

packages/rum-core/src/common/apm-server.js

@@ -82,15 +82,16 @@ class ApmServer {
       'Content-Type': 'application/x-ndjson'
     }
     const apmRequest = this._configService.get('apmRequest')
-    return compressPayload(payload, headers)
+    const params = { payload, headers, beforeSend: apmRequest }
+    return compressPayload(params)
       .catch(error => {
         if (__DEV__) {
           this._loggingService.debug(
             'Compressing the payload using CompressionStream API failed',
             error.message
           )
         }
-        return { payload, headers, beforeSend: apmRequest }
+        return params
       })
       .then(result => this._makeHttpRequest('POST', endPoint, result))
       .then(({ responseText }) => responseText)

packages/rum-core/src/common/compress.js

@@ -294,17 +294,17 @@ export function compressMetricsets(breakdowns) {
  * CompressionStream spec supported only in Chromium browsers
  * Spec : https://wicg.github.io/compression/
  */
-export function compressPayload(payload, headers, type = 'gzip') {
+export function compressPayload(params, type = 'gzip') {
   const isCompressionStreamSupported = typeof CompressionStream === 'function'
   return new Promise(resolve => {
     /**
      * Resolve with unmodified payload if the compression stream
      * is not supported in browser
      */
     if (!isCompressionStreamSupported) {
-      return resolve({ payload, headers })
+      return resolve(params)
     }
-
+    const { payload, headers, beforeSend } = params
     /**
      * create a blob with the original payload data and convert it
      * as readable stream
@@ -323,7 +323,7 @@ export function compressPayload(payload, headers, type = 'gzip') {
      */
     return new Response(compressedStream).blob().then(payload => {
       headers['Content-Encoding'] = type
-      return resolve({ payload, headers })
+      return resolve({ payload, headers, beforeSend })
     })
   })
 }

packages/rum-core/test/benchmarks/compress.bench.js

@@ -43,8 +43,9 @@ suite('Compress', () => {
     .join('')
 
   benchmark('compress payload', async () => {
-    await compressPayload(ndjsonPayload, {
-      'Content-Type': 'application/x-ndjson'
+    await compressPayload({
+      payload: ndjsonPayload,
+      headers: { 'Content-Type': 'application/x-ndjson' }
     })
   })
 })

packages/rum-core/test/common/compress.spec.js

@@ -297,10 +297,10 @@ describe('Compress', function () {
       .join('')
     const isCompressionStreamSupported = typeof CompressionStream === 'function'
     const originalHeaders = { 'Content-Type': 'application/x-ndjson' }
-    let { payload, headers } = await compressPayload(
-      ndjsonPayload,
-      originalHeaders
-    )
+    let { payload, headers } = await compressPayload({
+      payload: ndjsonPayload,
+      headers: originalHeaders
+    })
     if (isCompressionStreamSupported) {
       const decompressedBlob = await decompressPayload(payload)
       payload = await view(decompressedBlob)

packages/rum/test/e2e/general-usecase/app.js

@@ -40,8 +40,8 @@ const elasticApm = createApmBase({
   pageLoadSpanId: 'bbd8bcc3be14d814',
   pageLoadSampled: true,
   session: true,
-  apmRequest(xhr) {
-    xhr.setRequestHeader('custom', 'value')
+  apmRequest: ({ xhr }) => {
+    xhr.setRequestHeader('x-custom-header', 'foo')
     return true
   }
 })