Browser agent release notesRSS

New Features

Enable back/forward cache

Updating the agent default configuration to enable the back/forward cache feature previously released in version 1222 by default.

Bug Fixes

Revert xhr deny list timeslice metrics

Customers were losing visibility into all calls on the page when denying timeslice metrics based on the deny list. This change reverts to the behavior seen in all previous versions of the browser agent.

Handle unhandledPromiseRejections more gracefully

The agent will attempt to handle niche objects throw from unhandledPromiseRejection events more gracefully. These cases could include objects with frozen or static properties, or custom extensions of the Error class without a set method in place.

Disable metrics for missing entitlement

Fixing issue where metrics harvesting was not being halted when the agent RUM call indicated the account did not have entitlement to the jserrors endpoint. Before this change, customers missing this entitlement would see network calls to the New Relic jserrors endpoint result in 403 or 409 errors.

New Features

Gracefully abort agent if not fully instantiated

When importing of agent code fails, as when content gets blocked, the agent will clean up memory, the global scope, and any wrapped or modified APIs as much as feasible.

Bug Fixes

Resolve Google indexing of agent relative paths

In previous versions, the agent script included relative paths to its lazy-loaded chunks, which Googlebot picked up and attempted to index as pages. This change removes those relatives paths from the loader and centralizes our lazy chunk loading of agent features.

Refactor wrapping of Promise object

The agent's wrapping of the Promise object has been refactored to address conflicts with third party libraries and to add newer methods available on the native object. The new wrapping implementation is more conventional and less error-prone.

Fix uncaught promise error introduced in v1223

In some cases of failure to import agent script chunk "629", an error was thrown rather than caught and logged as a warning. The uncaught promise error responsible for this unintended behavior has been fixed.

New Features

Support SPA, XHR, and session trace features on Chrome for iOS

Previously, the agent didn't collect SPA browser interactions, XHR events, or session trace data in Chrome for iOS, which uses the webkit engine with modifications. The agent now collects the same data in Chrome for iOS as in other supported browsers.

Expose build version to newrelic global

The build version is exposed to the newrelic global object. You can access it with newrelic.intializedAgents[<agentID>].runtime.version.

Internal

Add automation for documentation site updates on new releases

A new release of the browser agent will automatically raise a PR to the documentation site with the relevant changelog items.

Bug Fixes

Fix multiple custom interaction end times

Fixed an issue where multiple custom interactions harvested at the same time would result in only one interaction being persisted in New Relic.

Prevent AJAX time slice metrics based on deny list

Prevent time slice metric collection for AJAX calls when such a call matches an entry in the AJAX deny list.

Bind navigator scope to sendBeacon

Some browser versions will throw errors if sendBeacon doesn't have the navigator scope bound to it. A fail-safe action of binding the navigator scope to sendBeacon was added to try to support those browsers.

Preserve unhandledPromiseRejection reasons as human-readable strings in error payloads

The agent will attempt to preserve unhandledPromiseRejection reasons as human-readable messages on the Error payload that gets harvested. The previous strategy didn't always work, because Promise.reject can pass any value, not just strings.

Fix missing interactions for dynamic routes in Next/React

Fixed an issue where when using the SPA loader with Next/React, route changes that lazy loaded components wouldn't be captured. While the issue specifically called out Next/React, this should apply to Nuxt/Vue and Angular.

Fix interactions missing API calls in Angular

Fixed an issue where when using the SPA loader with Angular, route changes that contained API calls, via Angular resolver, wouldn't capture the xhr/fetch on the interaction. This works with eager and lazy routes in an Angular SPA.

Support statement:

New Relic recommends that you upgrade the agent regularly to ensure that you're getting the latest features and performance benefits. Older releases will no longer be supported when they reach end-of-life. Release dates are reflective of the original publish date of the agent version.

New Browser Agent releases are rolled out to customers in small stages over a period of time. Because of this, the date the release becomes accessible to your account may not match the original publish date. Please see this status dashboard for more information.

Refactor loader architecture for improved developer experience

This architectural release simplifies file structure and refactors the way features are composed, in preparation for future developer experience improvements. These changes are not anticipated to have impact on agent behavior or functionality.

New Features

EXPERIMENTAL - Unblock instrumented pages from the back/forward cache (w/ feature flag)

An instrumented page's back-forward cache eligibility was hampered by the agent's unload listener, which will be removed when a feature flag is on. With the allow_bfcache enabled in the init config, the agent's definition of (the end of) an user's session is more refined, and it will no longer be blocking the browser from utilizing its respective b/f cache.

Internal

Reduce size of builds for modern browser targets

The agent is now compatible with only modern web syntax (ES6+); this reduces loader size for these browsers by 20% or more. We target and test support for just the last ten versions of Chrome, Edge, Safari, and Firefox -- see browser agent EOL policy for more details.

Bug Fixes

Prevent feature from collecting and harvesting future data if account entitlements are invalid

The agent will now attempt to shut down an initialized feature if account entitlements are invalid. Accounts that lack entitlements to use certain endpoints will see many 403 errors in the console without this behavior. This behavior requires the Page View Event feature to be enabled.

Do not collect XHR events for data URLs

AJAX events for data URLs have not historically been collected due to errors in the agent when handling URLs without hostnames. Going forward, XHR calls to data URLs will not cause agent errors and will continue to be excluded from collection.

Fix nrWrapper exclusion in error stack traces

Restoring previous functionality whereby the nrWrapper agent method should be excluded from JavaScript error stack traces.

Fix errors with global self redefinition

Fixing an issue where external code redefining the self global variable causes the agent async loading to fail and the agent to crash.

Fix check for sessionStorage object

Ensure the agent does not crash when sessionStorage is not available or when the quota has been exceeded or set to 0.

New Features

Add infrastructure to run on web workers

The agent's infrastructure will now allow for the agent to be built to run on web workers for future projects.

Bug Fixes

Expose webpack library as output type "self" vs. "umd"

To address "mismatched anonymous define" errors thrown by RequireJS, the agent's webpack library output will no longer include UMD checks for CommonJS and AMD module environments, and will instead be exposed globally via self.

Fix custom attribute handling in cases where the info block is loaded after initialization

Fixed an issue where custom attributes could be cleared and reset if the info block was included on the page below the loader script. Our guidance still remains that all configurations should be included on the page above the loader code, however this is an attempt to do no harm when feasible for backwards compatibility.

Update JS error bucketing algorithm

The agent will now take into account the error object type, message, and original stack trace when deciding on whether multiple JS errors should be bucketed together.

Fix initial page load interaction reporting with Nuxt

Fixed an issue where when using the SPA loader with Nuxt, the initial page load interaction was never being completed. This resulted in events like errors being retained in memory and never harvested because they were tied to an incomplete interaction.

Fix error with jsPDF library and SPA agent

Fixed an issue with the jsPDF library where it was not correctly detecting browser native support for Promises due to our wrapper. This resulted in an exception and jsPDF not generating the PDF. This issue is not present with the pro or lite agent.

Note: This issue does not affect the pro or lite agent. This change allows the jsPDF library to function correctly when the SPA agent is used. However, it does cause an internal error within the agent to be generated. This error does not break the agent, jsPDF, or other functionality. The issue is planned to be addressed in a future update.

This release is in public preview. We're slowly rolling out these features to different browser agents based on the browser's instrumentation method. Here's the release timeline:

• Internal NR Platform release date: 10/07/2022
• Production APM-injected release date: 10/7/2022
• Production Standalone release date: Estimated around 12/13/2022

New Features

Capture unhandled Promise rejections

The Agent now observes and captures unhandled Promise rejections as JavaScript Error objects.

Removed 3rd Party Cookies

The browser agent no longer uses 3rd party cookies to maintain and track session information. 1st party implementation using window.sessionStorage is now used, which is automatically cleared when a page session ends. This is still managed using the privacy settings form in your browser application settings.

LCP is no longer reported on initially-hidden pages

LCP metrics are no longer reported on pages whose state is hidden at load time, such as tabs refreshing in the background of a focused tab.

Async Module Loading

Individual features of the browser agent can now be dynamically loaded, enabled, or disabled at runtime.

Removal of script tag injection

The agent no longer inserts other features into the page via a script tag insertion. It now uses network requests to instantiate other code modules.

Updated test process

In an effort to better support the majority of our traffic, the test suite required to merge PRs has been updated to run against the latest 10 major versions of Chrome, Firefox, Edge, Android, and the latest 5 major versions of Safari and iOS. As part of this process, outdated code and polyfill libraries aimed at supporting deprecated browsers are no longer included in production builds by default.

Bug Fixes

Fixed issue with BrowserInteraction nodes generating circular references

BrowserInteractions no longer generate circular trees when they are self referential.

Remove non-ASCII characters from builds

Certain dependencies were appending non-ASCII characters to build files. These characters were affecting older Python agent implementations downstream that worked to parse and encode the agent snippet. The build files are now checked and cleaned of non-ASCII characters before shipping.

• Internal NR Platform release date: 04/19/2022
• Production APM-injected release date: 04/20/2022
• Production Standalone release date: 04/27/2022

New Features

Introduced obfuscation mechanism to payloads

Added internal mechanism for applying regex and replacement rules to all strings in payloads to obfuscate before sending to ingest.

Automatically obfuscate file:// protocol

A change has been implemented in our handling of applications hosted locally on a file:// protocol. For security reasons, we can not send payloads that contain file information, so our previous implementation revolved around completely shutting the agent down when file:// protocols were detected. This change automatically obfuscates all file:// paths from our payloads before sending to ingest.

Bug Fixes

Fixed issue with trace ID random hex character length

The final character in trace ID hex generation was returning as undefined, which translated to always be 0 (undefined & 15 === 0). This change fixes this final character and ensures it is valid.

Improvements

• Internal NR Platform release date: 01/24/2021
• Production APM-injected release date: TBD
• Production Standalone release date: TBD

Collect supportability metrics for frontend frameworks

Added frontend framework detection metrics to help guide future priorities for browser agent features. The following frontend frameworks will now be detected and analyzed:

• React
• Angular
• AngularJS
• Backbone
• Ember
• Vue
• Meteor
• Zepto
• Jquery