Notable Changes:
Diagnostics channel (experimental module):
`diagnostics_channel` is a new experimental module that provides an API
to create named channels to report arbitrary message data for
diagnostics purposes.
The module was initially introduced in Node.js v15.1.0 and is
backported to v14.17.0 to enable testing it at a larger scale.
With `diagnostics_channel`, Node.js core and module authors can publish
contextual data about what they are doing at a given time. This could
be the hostname and query string of a mysql query, for example. Just
create a named channel with `dc.channel(name)` and call
`channel.publish(data)` to send the data to any listeners to that
channel.
```js
const dc = require('diagnostics_channel');
const channel = dc.channel('mysql.query');
MySQL.prototype.query = function query(queryString, values, callback) {
// Broadcast query information whenever a query is made
channel.publish({
query: queryString,
host: this.hostname,
});
this.doQuery(queryString, values, callback);
};
```
Channels are like one big global event emitter but are split into
separate objects to ensure they get the best performance. If nothing is
listening to the channel, the publishing overhead should be as close to
zero as possible. Consuming channel data is as easy as using
`channel.subscribe(listener)` to run a function whenever a message is
published to that channel.
```js
const dc = require('diagnostics_channel');
const channel = dc.channel('mysql.query');
channel.subscribe(({ query, host }) => {
console.log(`mysql query to ${host}: ${query}`);
});
```
The data captured can be used to provide context for what an app is
doing at a given time. This can be used for things like augmenting
tracing data, tracking network and filesystem activity, logging
queries, and many other things. It's also a very useful data source
for diagnostics tools to provide a clearer picture of exactly what the
application is doing at a given point in the data they are presenting.
Contributed by Stephen Belanger (https://github.com/nodejs/node/pull/34895).
UUID support in the crypto module:
The new `crypto.randomUUID()` method now allows to generate random
[RFC 4122](https://www.rfc-editor.org/rfc/rfc4122.txt) Version 4
UUID strings:
```js
const { randomUUID } = require('crypto');
console.log(randomUUID());
// 'aa7c91a1-f8fc-4339-b9db-f93fc7233429'
```
Contributed by James M Snell (https://github.com/nodejs/node/pull/36729).
Experimental support for `AbortController` and `AbortSignal`:
Node.js 14.17.0 adds experimental partial support for `AbortController`
and `AbortSignal`.
Both constructors can be enabled globally using the
`--experimental-abortcontroller` flag.
Additionally, several Node.js APIs have been updated to support
`AbortSignal` for cancellation.
It is not mandatory to use the built-in constructors with them. Any
spec-compliant third-party alternatives should be compatible.
`AbortSignal` support was added to the following methods:
* `child_process.exec`
* `child_process.execFile`
* `child_process.fork`
* `child_process.spawn`
* `dgram.createSocket`
* `events.on`
* `events.once`
* `fs.readFile`
* `fs.watch`
* `fs.writeFile`
* `http.request`
* `https.request`
* `http2Session.request`
* The promisified variants of `setImmediate` and `setTimeout`
Other notable changes:
* doc:
* revoke deprecation of legacy url, change status to legacy (James M Snell) (https://github.com/nodejs/node/pull/37784)
* add legacy status to stability index (James M Snell) (https://github.com/nodejs/node/pull/37784)
* upgrade stability status of report API (Gireesh Punathil) (https://github.com/nodejs/node/pull/35654)
* deps:
* V8: Backport various patches for Apple Silicon support (BoHong Li) (https://github.com/nodejs/node/pull/38051)
* update ICU to 68.1 (Michaël Zasso) (https://github.com/nodejs/node/pull/36187)
* upgrade to libuv 1.41.0 (Colin Ihrig) (https://github.com/nodejs/node/pull/37360)
* http:
* add http.ClientRequest.getRawHeaderNames() (simov) (https://github.com/nodejs/node/pull/37660)
* report request start and end with diagnostics\_channel (Stephen Belanger) (https://github.com/nodejs/node/pull/34895)
* util:
* add getSystemErrorMap() impl (eladkeyshawn) (https://github.com/nodejs/node/pull/38101)
PR-URL: https://github.com/nodejs/node/pull/38507
* sort references in ASCII order
* merge logically-connected single-sentence paragraphs
* remove _please_ from referrals to other docs
* remove unnecessary italics
* make some text more concise
* change some instances of future tense to present tense
PR-URL: https://github.com/nodejs/node/pull/35152
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
This PR defines two new modes for the --unhandled-rejections flag.
The first mode is called "throw". The "throw" mode first emits
unhandledRejection. If this hook is not set, the "throw" mode will
raise the unhandled rejection as an uncaught exception.
The second mode is called "warn-with-error-code". The
"warn-with-error-code" mode first emits unhandledRejection. If this
hook is not set, the "warn-with-error-code" mode will trigger a
warning and set the process's exit code to 1.
The PR doesn't change the default behavior for unhandled rejections.
That will come in a separate PR.
Refs: https://github.com/nodejs/node/pull/33021
PR-URL: https://github.com/nodejs/node/pull/33475
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Deprecations:
- (SEMVER-MAJOR) crypto: move pbkdf2 without digest to EOL
(James M Snell) [#31166](https://github.com/nodejs/node/pull/31166)
- (SEMVER-MAJOR) fs: deprecate closing FileHandle on garbage collection
(James M Snell) [#28396](https://github.com/nodejs/node/pull/28396)
- (SEMVER-MAJOR) http: move OutboundMessage.prototype.flush to EOL
(James M Snell) [#31164](https://github.com/nodejs/node/pull/31164)
- (SEMVER-MAJOR) lib: move GLOBAL and root aliases to EOL
(James M Snell) [#31167](https://github.com/nodejs/node/pull/31167)
- (SEMVER-MAJOR) os: move tmpDir() to EOL
(James M Snell)[#31169](https://github.com/nodejs/node/pull/31169)
- (SEMVER-MAJOR) src: remove deprecated wasm type check
(Clemens Backes) [#32116](https://github.com/nodejs/node/pull/32116)
- (SEMVER-MAJOR) stream: move \_writableState.buffer to EOL
(James M Snell) [#31165](https://github.com/nodejs/node/pull/31165)
- (SEMVER-MINOR) doc: deprecate process.mainModule
(Antoine du HAMEL) [#32232](https://github.com/nodejs/node/pull/32232)
- (SEMVER-MINOR) doc: deprecate process.umask() with no arguments
(Colin Ihrig) [#32499](https://github.com/nodejs/node/pull/32499)
ECMAScript Modules - Experimental Warning Removal:
- module: remove experimental modules warning
(Guy Bedford) [#31974](https://github.com/nodejs/node/pull/31974)
In Node.js 13 we removed the need to include the --experimental-modules
flag, but when running EcmaScript Modules in Node.js, this would still
result in a warning ExperimentalWarning: The ESM module loader is
experimental.
As of Node.js 14 there is no longer this warning when using ESM in
Node.js. However, the ESM implementation in Node.js remains
experimental. As per our stability index: “The feature is not subject
to Semantic Versioning rules. Non-backward compatible changes or
removal may occur in any future release.” Users should be cautious when
using the feature in production environments.
Please keep in mind that the implementation of ESM in Node.js differs
from the developer experience you might be familiar with. Most
transpilation workflows support features such as optional file
extensions or JSON modules that the Node.js ESM implementation does not
support. It is highly likely that modules from transpiled environments
will require a certain degree of refactoring to work in Node.js. It is
worth mentioning that many of our design decisions were made with two
primary goals. Spec compliance and Web Compatibility. It is our belief
that the current implementation offers a future proof model to
authoring ESM modules that paves the path to Universal JavaScript.
Please read more in our documentation.
The ESM implementation in Node.js is still experimental but we do believe
that we are getting very close to being able to call ESM in Node.js
“stable”. Removing the warning is a huge step in that direction.
New V8 ArrayBuffer API:
* **src**: migrate to new V8 ArrayBuffer API
(Thang Tran) [#30782](https://github.com/nodejs/node/pull/30782)
Multiple ArrayBuffers pointing to the same base address are no longer
allowed by V8. This may impact native addons.
Toolchain and Compiler Upgrades:
- (SEMVER-MAJOR) build: update macos deployment target to 10.13 for 14.x
(AshCripps)[#32454](https://github.com/nodejs/node/pull/32454)
- (SEMVER-MAJOR) doc: update cross compiler machine for Linux armv7
(Richard Lau) [#32812](https://github.com/nodejs/node/pull/32812)
- (SEMVER-MAJOR) doc: update Centos/RHEL releases use devtoolset-8
(Richard Lau) [#32812](https://github.com/nodejs/node/pull/32812)
- (SEMVER-MAJOR) doc: remove SmartOS from official binaries
(Richard Lau) [#32812](https://github.com/nodejs/node/pull/32812)
- (SEMVER-MAJOR) win: block running on EOL Windows versions
(João Reis) [#31954](https://github.com/nodejs/node/pull/31954)
It is expected that there will be an ABI mismatch on ARM between the
Node.js binary and native addons. Native addons are only broken if they
interact with `std::shared_ptr`. This is expected to be fixed in a
later version of Node.js 14.
- [#30786](https://github.com/nodejs/node/issues/30786)
Update to V8 8.1:
- (SEMVER-MAJOR) deps: update V8 to 8.1.307.20
(Matheus Marchini) [#32116](https://github.com/nodejs/node/pull/32116)
Other Notable Changes:
- cli, report: move --report-on-fatalerror to stable
(Colin Ihrig) [#32496](https://github.com/nodejs/node/pull/32496)
- deps: upgrade to libuv 1.37.0
(Colin Ihrig) [#32866](https://github.com/nodejs/node/pull/32866)
- fs: add fs/promises alias module
(Gus Caplan) [#31553](https://github.com/nodejs/node/pull/31553)
PR-URL: https://github.com/nodejs/node/pull/32181
Multi-line JSON is more human readable, but harder for log aggregators
to consume, they usually require a log message per line, particularly
for JSON. Compact output will be consumable by aggregators such as EFK
(Elastic Search-Fluentd-Kibana), LogDNA, DataDog, etc.
PR-URL: https://github.com/nodejs/node/pull/32254
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Jayden Seric