fix: Handle chunk load promise error introduced in 1.235.0

src/features/session_replay/replay-mode.js

@@ -15,8 +15,8 @@ export async function getSessionReplayMode (agentId) {
     const newrelic = gosNREUM()
     // Should be enabled by configuration and using an agent build that includes it (via checking that the instrument class was initialized).
     if (getConfigurationValue(agentId, 'session_replay.enabled') && typeof newrelic.initializedAgents[agentId].features.session_replay === 'object') {
-      await newrelic.initializedAgents[agentId].features.session_replay.onAggregateImported // if Replay could not initialize, this throws a (uncaught) rejection
-      return await sharedChannel.sessionReplayInitialized // wait for replay to determine which mode it's after running its sampling logic
+      const srInitialized = await newrelic.initializedAgents[agentId].features.session_replay.onAggregateImported
+      if (srInitialized) return await sharedChannel.sessionReplayInitialized // wait for replay to determine which mode it's after running its sampling logic
     }
   } catch (e) { /* exception ==> off */ }
   return MODE.OFF // at any step of the way s.t. SR cannot be on by implication or is explicitly off

src/features/utils/instrument-base.js

@@ -56,8 +56,8 @@ export class InstrumentBase extends FeatureBase {
     if (this.featAggregate || !this.auto) return
     const enableSessionTracking = isBrowserScope && getConfigurationValue(this.agentIdentifier, 'privacy.cookies_enabled') === true
     let loadedSuccessfully, loadFailed
-    this.onAggregateImported = new Promise((resolve, reject) => {
-      loadedSuccessfully = resolve; loadFailed = reject
+    this.onAggregateImported = new Promise(resolve => {
+      loadedSuccessfully = resolve
     })
 
     const importLater = async () => {
@@ -83,12 +83,12 @@ export class InstrumentBase extends FeatureBase {
         const { lazyFeatureLoader } = await import(/* webpackChunkName: "lazy-feature-loader" */ './lazy-feature-loader')
         const { Aggregate } = await lazyFeatureLoader(this.featureName, 'aggregate')
         this.featAggregate = new Aggregate(this.agentIdentifier, this.aggregator, argsObjFromInstrument)
-        loadedSuccessfully()
+        loadedSuccessfully(true)
       } catch (e) {
         warn(`Downloading and initializing ${this.featureName} failed...`, e)
         this.abortHandler?.() // undo any important alterations made to the page
         // not supported yet but nice to do: "abort" this agent's EE for this feature specifically
-        loadFailed()
+        loadedSuccessfully(false)
       }
     }
 

src/features/utils/instrument-base.test.js

@@ -57,7 +57,7 @@ beforeEach(() => {
   aggregator = {}
   featureName = faker.datatype.uuid()
 
-  mockAggregate = jest.fn(() => { /* noop */ })
+  mockAggregate = jest.fn()
   jest.mocked(lazyFeatureLoader).mockResolvedValue({ Aggregate: mockAggregate })
 })
 
@@ -187,4 +187,23 @@ test('feature still imports by default even when setupAgentSession throws an err
   expect(warn).toHaveBeenCalledWith(expect.stringContaining('A problem occurred when starting up session manager'), expect.any(Error))
   expect(lazyFeatureLoader).toHaveBeenCalled()
   expect(mockAggregate).toHaveBeenCalled()
+  await expect(instrument.onAggregateImported).resolves.toBe(true)
+})
+
+test('no uncaught async exception is thrown when an import fails', async () => {
+  jest.mocked(lazyFeatureLoader).mockRejectedValue(new Error('ChunkLoadError')) // () => { throw new Error('ChunkLoadError: loading chunk xxx failed.') })
+  const mockOnError = jest.fn()
+  global.onerror = mockOnError
+
+  const instrument = new InstrumentBase(agentIdentifier, aggregator, featureName)
+  instrument.abortHandler = jest.fn()
+  instrument.importAggregator()
+
+  const windowLoadCallback = jest.mocked(onWindowLoad).mock.calls[0][0]
+  await windowLoadCallback()
+
+  expect(warn).toHaveBeenNthCalledWith(2, expect.stringContaining(`Downloading and initializing ${featureName} failed`), expect.any(Error))
+  expect(instrument.abortHandler).toHaveBeenCalled()
+  await expect(instrument.onAggregateImported).resolves.toBe(false)
+  expect(mockOnError).not.toHaveBeenCalled()
 })