Node.js APIs might be deprecated for any of the following reasons:
Node.js uses three kinds of Deprecations:
A Documentation-only deprecation is one that is expressed only within the\nNode.js API docs. These generate no side-effects while running Node.js.\nSome Documentation-only deprecations trigger a runtime warning when launched\nwith --pending-deprecation flag (or its alternative,\nNODE_PENDING_DEPRECATION=1 environment variable), similarly to Runtime\ndeprecations below. Documentation-only deprecations that support that flag\nare explicitly labeled as such in the\nlist of Deprecated APIs.
--pending-deprecation
NODE_PENDING_DEPRECATION=1
A Runtime deprecation will, by default, generate a process warning that will\nbe printed to stderr the first time the deprecated API is used. When the\n--throw-deprecation command-line flag is used, a Runtime deprecation will\ncause an error to be thrown.
stderr
--throw-deprecation
An End-of-Life deprecation is used when functionality is or will soon be removed\nfrom Node.js.
Occasionally, the deprecation of an API might be reversed. In such situations,\nthis document will be updated with information relevant to the decision.\nHowever, the deprecation identifier will not be modified.
Type: End-of-Life
OutgoingMessage.prototype.flush() has been removed. Use\nOutgoingMessage.prototype.flushHeaders() instead.
OutgoingMessage.prototype.flush()
OutgoingMessage.prototype.flushHeaders()
The _linklist module is deprecated. Please use a userland alternative.
_linklist
The _writableState.buffer has been removed. Use _writableState.getBuffer()\ninstead.
_writableState.buffer
_writableState.getBuffer()
The CryptoStream.prototype.readyState property was removed.
CryptoStream.prototype.readyState
Type: Runtime (supports --pending-deprecation)
The Buffer() function and new Buffer() constructor are deprecated due to\nAPI usability issues that can lead to accidental security issues.
Buffer()
new Buffer()
As an alternative, use one of the following methods of constructing Buffer\nobjects:
Buffer
Buffer.alloc(size[, fill[, encoding]])
Buffer.allocUnsafe(size)
Buffer.allocUnsafeSlow(size)
Buffer.from(array)
array
Buffer.from(arrayBuffer[, byteOffset[, length]])
arrayBuffer
Buffer.from(buffer)
buffer
Buffer.from(string[, encoding])
string
Without --pending-deprecation, runtime warnings occur only for code not in\nnode_modules. This means there will not be deprecation warnings for\nBuffer() usage in dependencies. With --pending-deprecation, a runtime\nwarning results no matter where the Buffer() usage occurs.
node_modules
Within the child_process module's spawn(), fork(), and exec()\nmethods, the options.customFds option is deprecated. The options.stdio\noption should be used instead.
child_process
spawn()
fork()
exec()
options.customFds
options.stdio
In an earlier version of the Node.js cluster, a boolean property with the name\nsuicide was added to the Worker object. The intent of this property was to\nprovide an indication of how and why the Worker instance exited. In Node.js\n6.0.0, the old property was deprecated and replaced with a new\nworker.exitedAfterDisconnect property. The old property name did not\nprecisely describe the actual semantics and was unnecessarily emotion-laden.
cluster
suicide
Worker
worker.exitedAfterDisconnect
Type: Documentation-only
The node:constants module is deprecated. When requiring access to constants\nrelevant to specific Node.js builtin modules, developers should instead refer\nto the constants property exposed by the relevant module. For instance,\nrequire('node:fs').constants and require('node:os').constants.
node:constants
constants
require('node:fs').constants
require('node:os').constants
Use of the crypto.pbkdf2() API without specifying a digest was deprecated\nin Node.js 6.0 because the method defaulted to using the non-recommended\n'SHA1' digest. Previously, a deprecation warning was printed. Starting in\nNode.js 8.0.0, calling crypto.pbkdf2() or crypto.pbkdf2Sync() with\ndigest set to undefined will throw a TypeError.
crypto.pbkdf2()
'SHA1'
crypto.pbkdf2Sync()
digest
undefined
TypeError
Beginning in Node.js v11.0.0, calling these functions with digest set to\nnull would print a deprecation warning to align with the behavior when digest\nis undefined.
null
Now, however, passing either undefined or null will throw a TypeError.
The crypto.createCredentials() API was removed. Please use\ntls.createSecureContext() instead.
crypto.createCredentials()
tls.createSecureContext()
The crypto.Credentials class was removed. Please use tls.SecureContext\ninstead.
crypto.Credentials
tls.SecureContext
Domain.dispose() has been removed. Recover from failed I/O actions\nexplicitly via error event handlers set on the domain instead.
Domain.dispose()
Calling an asynchronous function without a callback throws a TypeError\nin Node.js 10.0.0 onwards. See https://github.com/nodejs/node/pull/12562.
The fs.read() legacy String interface is deprecated. Use the Buffer\nAPI as mentioned in the documentation instead.
fs.read()
String
The fs.readSync() legacy String interface is deprecated. Use the\nBuffer API as mentioned in the documentation instead.
fs.readSync()
The GLOBAL and root aliases for the global property were deprecated\nin Node.js 6.0.0 and have since been removed.
GLOBAL
root
global
Intl.v8BreakIterator was a non-standard extension and has been removed.\nSee Intl.Segmenter.
Intl.v8BreakIterator
Intl.Segmenter
Unhandled promise rejections are deprecated. By default, promise rejections\nthat are not handled terminate the Node.js process with a non-zero exit\ncode. To change the way Node.js treats unhandled rejections, use the\n--unhandled-rejections command-line option.
--unhandled-rejections
In certain cases, require('.') could resolve outside the package directory.\nThis behavior has been removed.
require('.')
The Server.connections property was deprecated in Node.js v0.9.7 and has\nbeen removed. Please use the Server.getConnections() method instead.
Server.connections
Server.getConnections()
The Server.listenFD() method was deprecated and removed. Please use\nServer.listen({fd: <number>}) instead.
Server.listenFD()
Server.listen({fd: <number>})
The os.tmpDir() API was deprecated in Node.js 7.0.0 and has since been\nremoved. Please use os.tmpdir() instead.
os.tmpDir()
os.tmpdir()
The os.getNetworkInterfaces() method is deprecated. Please use the\nos.networkInterfaces() method instead.
os.getNetworkInterfaces()
os.networkInterfaces()
The REPLServer.prototype.convertToContext() API has been removed.
REPLServer.prototype.convertToContext()
Type: Runtime
The node:sys module is deprecated. Please use the util module instead.
node:sys
util
util.print() has been removed. Please use console.log() instead.
util.print()
console.log()
util.puts() has been removed. Please use console.log() instead.
util.puts()
util.debug() has been removed. Please use console.error() instead.
util.debug()
console.error()
util.error() has been removed. Please use console.error() instead.
util.error()
The SlowBuffer class is deprecated. Please use\nBuffer.allocUnsafeSlow(size) instead.
SlowBuffer
The ecdh.setPublicKey() method is now deprecated as its inclusion in the\nAPI is not useful.
ecdh.setPublicKey()
The domain module is deprecated and should not be used.
domain
The events.listenerCount(emitter, eventName) API is\ndeprecated. Please use emitter.listenerCount(eventName) instead.
events.listenerCount(emitter, eventName)
emitter.listenerCount(eventName)
The fs.exists(path, callback) API is deprecated. Please use\nfs.stat() or fs.access() instead.
fs.exists(path, callback)
fs.stat()
fs.access()
The fs.lchmod(path, mode, callback) API is deprecated.
fs.lchmod(path, mode, callback)
The fs.lchmodSync(path, mode) API is deprecated.
fs.lchmodSync(path, mode)
Type: Deprecation revoked
The fs.lchown(path, uid, gid, callback) API was deprecated. The\ndeprecation was revoked because the requisite supporting APIs were added in\nlibuv.
fs.lchown(path, uid, gid, callback)
The fs.lchownSync(path, uid, gid) API was deprecated. The deprecation was\nrevoked because the requisite supporting APIs were added in libuv.
fs.lchownSync(path, uid, gid)
The require.extensions property is deprecated.
require.extensions
Type: Documentation-only (supports --pending-deprecation)
The punycode module is deprecated. Please use a userland alternative\ninstead.
punycode
The NODE_REPL_HISTORY_FILE environment variable was removed. Please use\nNODE_REPL_HISTORY instead.
NODE_REPL_HISTORY_FILE
NODE_REPL_HISTORY
The tls.CryptoStream class was removed. Please use\ntls.TLSSocket instead.
tls.CryptoStream
tls.TLSSocket
The tls.SecurePair class is deprecated. Please use\ntls.TLSSocket instead.
tls.SecurePair
The util.isArray() API is deprecated. Please use Array.isArray()\ninstead.
util.isArray()
Array.isArray()
The util.isBoolean() API is deprecated.
util.isBoolean()
The util.isBuffer() API is deprecated. Please use\nBuffer.isBuffer() instead.
util.isBuffer()
Buffer.isBuffer()
The util.isDate() API is deprecated.
util.isDate()
The util.isError() API is deprecated.
util.isError()
The util.isFunction() API is deprecated.
util.isFunction()
The util.isNull() API is deprecated.
util.isNull()
The util.isNullOrUndefined() API is deprecated.
util.isNullOrUndefined()
The util.isNumber() API is deprecated.
util.isNumber()
The util.isObject() API is deprecated.
util.isObject()
The util.isPrimitive() API is deprecated.
util.isPrimitive()
The util.isRegExp() API is deprecated.
util.isRegExp()
The util.isString() API is deprecated.
util.isString()
The util.isSymbol() API is deprecated.
util.isSymbol()
The util.isUndefined() API is deprecated.
util.isUndefined()
The util.log() API is deprecated.
util.log()
The util._extend() API is deprecated.
util._extend()
The fs.SyncWriteStream class was never intended to be a publicly accessible\nAPI and has been removed. No alternative API is available. Please use a userland\nalternative.
fs.SyncWriteStream
--debug activates the legacy V8 debugger interface, which was removed as\nof V8 5.8. It is replaced by Inspector which is activated with --inspect\ninstead.
--debug
--inspect
The node:http module ServerResponse.prototype.writeHeader() API is\ndeprecated. Please use ServerResponse.prototype.writeHead() instead.
node:http
ServerResponse.prototype.writeHeader()
ServerResponse.prototype.writeHead()
The ServerResponse.prototype.writeHeader() method was never documented as an\nofficially supported API.
The tls.createSecurePair() API was deprecated in documentation in Node.js\n0.11.3. Users should use tls.Socket instead.
tls.createSecurePair()
tls.Socket
The node:repl module's REPL_MODE_MAGIC constant, used for replMode option,\nhas been removed. Its behavior has been functionally identical to that of\nREPL_MODE_SLOPPY since Node.js 6.0.0, when V8 5.0 was imported. Please use\nREPL_MODE_SLOPPY instead.
node:repl
REPL_MODE_MAGIC
replMode
REPL_MODE_SLOPPY
The NODE_REPL_MODE environment variable is used to set the underlying\nreplMode of an interactive node session. Its value, magic, is also\nremoved. Please use sloppy instead.
NODE_REPL_MODE
node
magic
sloppy
The node:http module OutgoingMessage.prototype._headers and\nOutgoingMessage.prototype._headerNames properties are deprecated. Use one of\nthe public methods (e.g. OutgoingMessage.prototype.getHeader(),\nOutgoingMessage.prototype.getHeaders(),\nOutgoingMessage.prototype.getHeaderNames(),\nOutgoingMessage.prototype.getRawHeaderNames(),\nOutgoingMessage.prototype.hasHeader(),\nOutgoingMessage.prototype.removeHeader(),\nOutgoingMessage.prototype.setHeader()) for working with outgoing headers.
OutgoingMessage.prototype._headers
OutgoingMessage.prototype._headerNames
OutgoingMessage.prototype.getHeader()
OutgoingMessage.prototype.getHeaders()
OutgoingMessage.prototype.getHeaderNames()
OutgoingMessage.prototype.getRawHeaderNames()
OutgoingMessage.prototype.hasHeader()
OutgoingMessage.prototype.removeHeader()
OutgoingMessage.prototype.setHeader()
The OutgoingMessage.prototype._headers and\nOutgoingMessage.prototype._headerNames properties were never documented as\nofficially supported properties.
The node:http module OutgoingMessage.prototype._renderHeaders() API is\ndeprecated.
OutgoingMessage.prototype._renderHeaders()
The OutgoingMessage.prototype._renderHeaders property was never documented as\nan officially supported API.
OutgoingMessage.prototype._renderHeaders
node debug corresponds to the legacy CLI debugger which has been replaced with\na V8-inspector based CLI debugger available through node inspect.
node debug
node inspect
DebugContext has been removed in V8 and is not available in Node.js 10+.
DebugContext was an experimental API.
async_hooks.currentId() was renamed to async_hooks.executionAsyncId() for\nclarity.
async_hooks.currentId()
async_hooks.executionAsyncId()
This change was made while async_hooks was an experimental API.
async_hooks
async_hooks.triggerId() was renamed to async_hooks.triggerAsyncId() for\nclarity.
async_hooks.triggerId()
async_hooks.triggerAsyncId()
async_hooks.AsyncResource.triggerId() was renamed to\nasync_hooks.AsyncResource.triggerAsyncId() for clarity.
async_hooks.AsyncResource.triggerId()
async_hooks.AsyncResource.triggerAsyncId()
Accessing several internal, undocumented properties of net.Server instances\nwith inappropriate names is deprecated.
net.Server
As the original API was undocumented and not generally useful for non-internal\ncode, no replacement API is provided.
The REPLServer.bufferedCommand property was deprecated in favor of\nREPLServer.clearBufferedCommand().
REPLServer.bufferedCommand
REPLServer.clearBufferedCommand()
REPLServer.parseREPLKeyword() was removed from userland visibility.
REPLServer.parseREPLKeyword()
tls.parseCertString() is a trivial parsing helper that was made public by\nmistake. This function can usually be replaced with:
tls.parseCertString()
const querystring = require('querystring');\nquerystring.parse(str, '\\n', '=');\n
This function is not completely equivalent to querystring.parse(). One\ndifference is that querystring.parse() does url decoding:
querystring.parse()
> querystring.parse('%E5%A5%BD=1', '\\n', '=');\n{ '好': '1' }\n> tls.parseCertString('%E5%A5%BD=1');\n{ '%E5%A5%BD': '1' }\n
Module._debug() is deprecated.
Module._debug()
The Module._debug() function was never documented as an officially\nsupported API.
REPLServer.turnOffEditorMode() was removed from userland visibility.
REPLServer.turnOffEditorMode()
Using a property named inspect on an object to specify a custom inspection\nfunction for util.inspect() is deprecated. Use util.inspect.custom\ninstead. For backward compatibility with Node.js prior to version 6.4.0, both\ncan be specified.
inspect
util.inspect()
util.inspect.custom
The internal path._makeLong() was not intended for public use. However,\nuserland modules have found it useful. The internal API is deprecated\nand replaced with an identical, public path.toNamespacedPath() method.
path._makeLong()
path.toNamespacedPath()
fs.truncate() fs.truncateSync() usage with a file descriptor is\ndeprecated. Please use fs.ftruncate() or fs.ftruncateSync() to work with\nfile descriptors.
fs.truncate()
fs.truncateSync()
fs.ftruncate()
fs.ftruncateSync()
REPLServer.prototype.memory() is only necessary for the internal mechanics of\nthe REPLServer itself. Do not use this function.
REPLServer.prototype.memory()
REPLServer
Type: End-of-Life.
The ecdhCurve option to tls.createSecureContext() and tls.TLSSocket could\nbe set to false to disable ECDH entirely on the server only. This mode was\ndeprecated in preparation for migrating to OpenSSL 1.1.0 and consistency with\nthe client and is now unsupported. Use the ciphers parameter instead.
ecdhCurve
false
ciphers
Since Node.js versions 4.4.0 and 5.2.0, several modules only intended for\ninternal usage were mistakenly exposed to user code through require(). These\nmodules were:
require()
v8/tools/codemap
v8/tools/consarray
v8/tools/csvparser
v8/tools/logreader
v8/tools/profile_view
v8/tools/profile
v8/tools/SourceMap
v8/tools/splaytree
v8/tools/tickprocessor-driver
v8/tools/tickprocessor
node-inspect/lib/_inspect
node-inspect/lib/internal/inspect_client
node-inspect/lib/internal/inspect_repl
The v8/* modules do not have any exports, and if not imported in a specific\norder would in fact throw errors. As such there are virtually no legitimate use\ncases for importing them through require().
v8/*
On the other hand, node-inspect can be installed locally through a package\nmanager, as it is published on the npm registry under the same name. No source\ncode modification is necessary if that is done.
node-inspect
The AsyncHooks sensitive API was never documented and had various minor issues.\nUse the AsyncResource API instead. See\nhttps://github.com/nodejs/node/issues/15572.
AsyncResource
runInAsyncIdScope doesn't emit the 'before' or 'after' event and can thus\ncause a lot of issues. See https://github.com/nodejs/node/issues/14328.
runInAsyncIdScope
'before'
'after'
Importing assert directly was not recommended as the exposed functions use\nloose equality checks. The deprecation was revoked because use of the\nnode:assert module is not discouraged, and the deprecation caused developer\nconfusion.
node:assert
Node.js used to support all GCM authentication tag lengths which are accepted by\nOpenSSL when calling decipher.setAuthTag(). Beginning with Node.js\nv11.0.0, only authentication tag lengths of 128, 120, 112, 104, 96, 64, and 32\nbits are allowed. Authentication tags of other lengths are invalid per\nNIST SP 800-38D.
decipher.setAuthTag()
The crypto.DEFAULT_ENCODING property is deprecated.
crypto.DEFAULT_ENCODING
Assigning properties to the top-level this as an alternative\nto module.exports is deprecated. Developers should use exports\nor module.exports instead.
this
module.exports
exports
The crypto.fips property is deprecated. Please use crypto.setFips()\nand crypto.getFips() instead.
crypto.fips
crypto.setFips()
crypto.getFips()
Using assert.fail() with more than one argument is deprecated. Use\nassert.fail() with only one argument or use a different node:assert module\nmethod.
assert.fail()
timers.enroll() is deprecated. Please use the publicly documented\nsetTimeout() or setInterval() instead.
timers.enroll()
setTimeout()
setInterval()
timers.unenroll() is deprecated. Please use the publicly documented\nclearTimeout() or clearInterval() instead.
timers.unenroll()
clearTimeout()
clearInterval()
Users of MakeCallback that add the domain property to carry context,\nshould start using the async_context variant of MakeCallback or\nCallbackScope, or the high-level AsyncResource class.
MakeCallback
async_context
CallbackScope
The embedded API provided by AsyncHooks exposes .emitBefore() and\n.emitAfter() methods which are very easy to use incorrectly which can lead\nto unrecoverable errors.
.emitBefore()
.emitAfter()
Use asyncResource.runInAsyncScope() API instead which provides a much\nsafer, and more convenient, alternative. See\nhttps://github.com/nodejs/node/pull/18513.
asyncResource.runInAsyncScope()
Type: Compile-time
Certain versions of node::MakeCallback APIs available to native addons are\ndeprecated. Please use the versions of the API that accept an async_context\nparameter.
node::MakeCallback
process.assert() is deprecated. Please use the assert module instead.
process.assert()
assert
This was never a documented feature.
The --with-lttng compile-time option has been removed.
--with-lttng
Using the noAssert argument has no functionality anymore. All input is\nverified regardless of the value of noAssert. Skipping the verification\ncould lead to hard-to-find errors and crashes.
noAssert
Using process.binding() in general should be avoided. The type checking\nmethods in particular can be replaced by using util.types.
process.binding()
util.types
This deprecation has been superseded by the deprecation of the\nprocess.binding() API (DEP0111).
When assigning a non-string property to process.env, the assigned value is\nimplicitly converted to a string. This behavior is deprecated if the assigned\nvalue is not a string, boolean, or number. In the future, such assignment might\nresult in a thrown error. Please convert the property to a string before\nassigning it to process.env.
process.env
decipher.finaltol() has never been documented and was an alias for\ndecipher.final(). This API has been removed, and it is recommended to use\ndecipher.final() instead.
decipher.finaltol()
decipher.final()
Using crypto.createCipher() and crypto.createDecipher() must be\navoided as they use a weak key derivation function (MD5 with no salt) and static\ninitialization vectors. It is recommended to derive a key using\ncrypto.pbkdf2() or crypto.scrypt() with random salts and to use\ncrypto.createCipheriv() and crypto.createDecipheriv() to obtain the\nCipher and Decipher objects respectively.
crypto.createCipher()
crypto.createDecipher()
crypto.scrypt()
crypto.createCipheriv()
crypto.createDecipheriv()
Cipher
Decipher
This was an undocumented helper function not intended for use outside Node.js\ncore and obsoleted by the removal of NPN (Next Protocol Negotiation) support.
Deprecated alias for zlib.bytesWritten. This original name was chosen\nbecause it also made sense to interpret the value as the number of bytes\nread by the engine, but is inconsistent with other streams in Node.js that\nexpose values under these names.
zlib.bytesWritten
Some previously supported (but strictly invalid) URLs were accepted through the\nhttp.request(), http.get(), https.request(),\nhttps.get(), and tls.checkServerIdentity() APIs because those were\naccepted by the legacy url.parse() API. The mentioned APIs now use the WHATWG\nURL parser that requires strictly valid URLs. Passing an invalid URL is\ndeprecated and support will be removed in the future.
http.request()
http.get()
https.request()
https.get()
tls.checkServerIdentity()
url.parse()
The produceCachedData option is deprecated. Use\nscript.createCachedData() instead.
produceCachedData
script.createCachedData()
process.binding() is for use by Node.js internal code only.
While process.binding() has not reached End-of-Life status in general, it is\nunavailable when policies are enabled.
The node:dgram module previously contained several APIs that were never meant\nto accessed outside of Node.js core: Socket.prototype._handle,\nSocket.prototype._receiving, Socket.prototype._bindState,\nSocket.prototype._queue, Socket.prototype._reuseAddr,\nSocket.prototype._healthCheck(), Socket.prototype._stopReceiving(), and\ndgram._createSocketHandle().
node:dgram
Socket.prototype._handle
Socket.prototype._receiving
Socket.prototype._bindState
Socket.prototype._queue
Socket.prototype._reuseAddr
Socket.prototype._healthCheck()
Socket.prototype._stopReceiving()
dgram._createSocketHandle()
Cipher.setAuthTag() and Decipher.getAuthTag() are no longer available. They\nwere never documented and would throw when called.
Cipher.setAuthTag()
Decipher.getAuthTag()
The crypto._toBuf() function was not designed to be used by modules outside\nof Node.js core and was removed.
crypto._toBuf()
In recent versions of Node.js, there is no difference between\ncrypto.randomBytes() and crypto.pseudoRandomBytes(). The latter is\ndeprecated along with the undocumented aliases crypto.prng() and\ncrypto.rng() in favor of crypto.randomBytes() and might be removed in a\nfuture release.
crypto.randomBytes()
crypto.pseudoRandomBytes()
crypto.prng()
crypto.rng()
The Legacy URL API is deprecated. This includes url.format(),\nurl.parse(), url.resolve(), and the legacy urlObject. Please\nuse the WHATWG URL API instead.
url.format()
url.resolve()
urlObject
Previous versions of Node.js exposed handles to internal native objects through\nthe _handle property of the Cipher, Decipher, DiffieHellman,\nDiffieHellmanGroup, ECDH, Hash, Hmac, Sign, and Verify classes.\nThe _handle property has been removed because improper use of the native\nobject can lead to crashing the application.
_handle
DiffieHellman
DiffieHellmanGroup
ECDH
Hash
Hmac
Sign
Verify
Previous versions of Node.js supported dns.lookup() with a falsy host name\nlike dns.lookup(false) due to backward compatibility.\nThis behavior is undocumented and is thought to be unused in real world apps.\nIt will become an error in future versions of Node.js.
dns.lookup()
dns.lookup(false)
process.binding('uv').errname() is deprecated. Please use\nutil.getSystemErrorName() instead.
process.binding('uv').errname()
util.getSystemErrorName()
Windows Performance Counter support has been removed from Node.js. The\nundocumented COUNTER_NET_SERVER_CONNECTION(),\nCOUNTER_NET_SERVER_CONNECTION_CLOSE(), COUNTER_HTTP_SERVER_REQUEST(),\nCOUNTER_HTTP_SERVER_RESPONSE(), COUNTER_HTTP_CLIENT_REQUEST(), and\nCOUNTER_HTTP_CLIENT_RESPONSE() functions have been deprecated.
COUNTER_NET_SERVER_CONNECTION()
COUNTER_NET_SERVER_CONNECTION_CLOSE()
COUNTER_HTTP_SERVER_REQUEST()
COUNTER_HTTP_SERVER_RESPONSE()
COUNTER_HTTP_CLIENT_REQUEST()
COUNTER_HTTP_CLIENT_RESPONSE()
The undocumented net._setSimultaneousAccepts() function was originally\nintended for debugging and performance tuning when using the\nnode:child_process and node:cluster modules on Windows. The function is not\ngenerally useful and is being removed. See discussion here:\nhttps://github.com/nodejs/node/issues/18391
net._setSimultaneousAccepts()
node:child_process
node:cluster
Please use Server.prototype.setSecureContext() instead.
Server.prototype.setSecureContext()
Setting the TLS ServerName to an IP address is not permitted by\nRFC 6066. This will be ignored in a future version.
This property is a reference to the instance itself.
The node:_stream_wrap module is deprecated.
node:_stream_wrap
The previously undocumented timers.active() is deprecated.\nPlease use the publicly documented timeout.refresh() instead.\nIf re-referencing the timeout is necessary, timeout.ref() can be used\nwith no performance impact since Node.js 10.
timers.active()
timeout.refresh()
timeout.ref()
The previously undocumented and \"private\" timers._unrefActive() is deprecated.\nPlease use the publicly documented timeout.refresh() instead.\nIf unreferencing the timeout is necessary, timeout.unref() can be used\nwith no performance impact since Node.js 10.
timers._unrefActive()
timeout.unref()
Modules that have an invalid main entry (e.g., ./does-not-exist.js) and\nalso have an index.js file in the top level directory will resolve the\nindex.js file. That is deprecated and is going to throw an error in future\nNode.js versions.
main
./does-not-exist.js
index.js
The _channel property of child process objects returned by spawn() and\nsimilar functions is not intended for public use. Use ChildProcess.channel\ninstead.
_channel
ChildProcess.channel
Use module.createRequire() instead.
module.createRequire()
The legacy HTTP parser, used by default in versions of Node.js prior to 12.0.0,\nis deprecated and has been removed in v13.0.0. Prior to v13.0.0, the\n--http-parser=legacy command-line flag could be used to revert to using the\nlegacy parser.
--http-parser=legacy
Passing a callback to worker.terminate() is deprecated. Use the returned\nPromise instead, or a listener to the worker's 'exit' event.
worker.terminate()
Promise
'exit'
Prefer response.socket over response.connection and\nrequest.socket over request.connection.
response.socket
response.connection
request.socket
request.connection
The process._tickCallback property was never documented as\nan officially supported API.
process._tickCallback
WriteStream.open() and ReadStream.open() are undocumented internal\nAPIs that do not make sense to use in userland. File streams should always be\nopened through their corresponding factory methods fs.createWriteStream()\nand fs.createReadStream()) or by passing a file descriptor in options.
WriteStream.open()
ReadStream.open()
fs.createWriteStream()
fs.createReadStream()
response.finished indicates whether response.end() has been\ncalled, not whether 'finish' has been emitted and the underlying data\nis flushed.
response.finished
response.end()
'finish'
Use response.writableFinished or response.writableEnded\naccordingly instead to avoid the ambiguity.
response.writableFinished
response.writableEnded
To maintain existing behavior response.finished should be replaced with\nresponse.writableEnded.
Allowing a fs.FileHandle object to be closed on garbage collection is\ndeprecated. In the future, doing so might result in a thrown error that will\nterminate the process.
fs.FileHandle
Please ensure that all fs.FileHandle objects are explicitly closed using\nFileHandle.prototype.close() when the fs.FileHandle is no longer needed:
FileHandle.prototype.close()
const fsPromises = require('node:fs').promises;\nasync function openAndClose() {\n let filehandle;\n try {\n filehandle = await fsPromises.open('thefile.txt', 'r');\n } finally {\n if (filehandle !== undefined)\n await filehandle.close();\n }\n}\n
process.mainModule is a CommonJS-only feature while process global\nobject is shared with non-CommonJS environment. Its use within ECMAScript\nmodules is unsupported.
process.mainModule
process
It is deprecated in favor of require.main, because it serves the same\npurpose and is only available on CommonJS environment.
require.main
Calling process.umask() with no argument causes the process-wide umask to be\nwritten twice. This introduces a race condition between threads, and is a\npotential security vulnerability. There is no safe, cross-platform alternative\nAPI.
process.umask()
Use request.destroy() instead of request.abort().
request.destroy()
request.abort()
The node:repl module exported the input and output stream twice. Use .input\ninstead of .inputStream and .output instead of .outputStream.
.input
.inputStream
.output
.outputStream
The node:repl module exports a _builtinLibs property that contains an array\nof built-in modules. It was incomplete so far and instead it's better to rely\nupon require('node:module').builtinModules.
_builtinLibs
require('node:module').builtinModules
Type: Runtime\nTransform._transformState will be removed in future versions where it is\nno longer required due to simplification of the implementation.
Transform._transformState
A CommonJS module can access the first module that required it using\nmodule.parent. This feature is deprecated because it does not work\nconsistently in the presence of ECMAScript modules and because it gives an\ninaccurate representation of the CommonJS module graph.
module.parent
Some modules use it to check if they are the entry point of the current process.\nInstead, it is recommended to compare require.main and module:
module
if (require.main === module) {\n // Code section that will run only if current file is the entry point.\n}\n
When looking for the CommonJS modules that have required the current one,\nrequire.cache and module.children can be used:
require.cache
module.children
const moduleParents = Object.values(require.cache)\n .filter((m) => m.children.includes(module));\n
socket.bufferSize is just an alias for writable.writableLength.
socket.bufferSize
writable.writableLength
The crypto.Certificate() constructor is deprecated. Use\nstatic methods of crypto.Certificate() instead.
crypto.Certificate()
In future versions of Node.js, recursive option will be ignored for\nfs.rmdir, fs.rmdirSync, and fs.promises.rmdir.
recursive
fs.rmdir
fs.rmdirSync
fs.promises.rmdir
Use fs.rm(path, { recursive: true, force: true }),\nfs.rmSync(path, { recursive: true, force: true }) or\nfs.promises.rm(path, { recursive: true, force: true }) instead.
fs.rm(path, { recursive: true, force: true })
fs.rmSync(path, { recursive: true, force: true })
fs.promises.rm(path, { recursive: true, force: true })
Using a trailing \"/\" to define\nsubpath folder mappings in the subpath exports or\nsubpath imports fields is deprecated. Use subpath patterns instead.
\"/\"
Type: Documentation-only.
Prefer message.socket over message.connection.
message.socket
message.connection
The process.config property provides access to Node.js compile-time settings.\nHowever, the property is mutable and therefore subject to tampering. The ability\nto change the value will be removed in a future version of Node.js.
process.config
Previously, index.js and extension searching lookups would apply to\nimport 'pkg' main entry point resolution, even when resolving ES modules.
import 'pkg'
With this deprecation, all ES module main entry point resolutions require\nan explicit \"exports\" or \"main\" entry with the exact file extension.
\"exports\"
\"main\"
The 'gc', 'http2', and 'http' <PerformanceEntry> object types have\nadditional properties assigned to them that provide additional information.\nThese properties are now available within the standard detail property\nof the PerformanceEntry object. The existing accessors have been\ndeprecated and should no longer be used.
'gc'
'http2'
'http'
detail
PerformanceEntry
Using a non-nullish non-integer value for family option, a non-nullish\nnon-number value for hints option, a non-nullish non-boolean value for all\noption, or a non-nullish non-boolean value for verbatim option in\ndns.lookup() and dnsPromises.lookup() is deprecated.
family
hints
all
verbatim
dnsPromises.lookup()
The 'hash' and 'mgf1Hash' options are replaced with 'hashAlgorithm'\nand 'mgf1HashAlgorithm'.
'hash'
'mgf1Hash'
'hashAlgorithm'
'mgf1HashAlgorithm'
The remapping of specifiers ending in \"/\" like import 'pkg/x/' is deprecated\nfor package \"exports\" and \"imports\" pattern resolutions.
import 'pkg/x/'
\"imports\"
Move to <Stream> API instead, as the http.ClientRequest,\nhttp.ServerResponse, and http.IncomingMessage are all stream-based.\nCheck stream.destroyed instead of the .aborted property, and listen for\n'close' instead of 'abort', 'aborted' event.
http.ClientRequest
http.ServerResponse
http.IncomingMessage
stream.destroyed
.aborted
'close'
'abort'
'aborted'
The .aborted property and 'abort' event are only useful for detecting\n.abort() calls. For closing a request early, use the Stream\n.destroy([error]) then check the .destroyed property and 'close' event\nshould have the same effect. The receiving end should also check the\nreadable.readableEnded value on http.IncomingMessage to get whether\nit was an aborted or graceful destroy.
.abort()
.destroy([error])
.destroyed
readable.readableEnded
An undocumented feature of Node.js streams was to support thenables in\nimplementation methods. This is now deprecated, use callbacks instead and avoid\nuse of async function for streams implementation methods.
This feature caused users to encounter unexpected problems where the user\nimplements the function in callback style but uses e.g. an async method which\nwould cause an error since mixing promise and callback semantics is not valid.
const w = new Writable({\n async final(callback) {\n await someOp();\n callback();\n }\n});\n
This method was deprecated because it is not compatible with\nUint8Array.prototype.slice(), which is a superclass of Buffer.
Uint8Array.prototype.slice()
Use buffer.subarray which does the same thing instead.
buffer.subarray
This event was deprecated because it did not work with V8 promise combinators\nwhich diminished its usefulness.
The process._getActiveHandles() and process._getActiveRequests()\nfunctions are not intended for public use and can be removed in future\nreleases.
process._getActiveHandles()
process._getActiveRequests()
Use process.getActiveResourcesInfo() to get a list of types of active\nresources and not the actual references.
process.getActiveResourcesInfo()
Implicit coercion of objects with own toString property, passed as second\nparameter in fs.write(), fs.writeFile(), fs.appendFile(),\nfs.writeFileSync(), and fs.appendFileSync() is deprecated.\nConvert them to primitive strings.
toString
fs.write()
fs.writeFile()
fs.appendFile()
fs.writeFileSync()
fs.appendFileSync()
These methods were deprecated because they can be used in a way which does not\nhold the channel reference alive long enough to receive the events.
Use diagnostics_channel.subscribe(name, onMessage) or\ndiagnostics_channel.unsubscribe(name, onMessage) which does the same\nthing instead.
diagnostics_channel.subscribe(name, onMessage)
diagnostics_channel.unsubscribe(name, onMessage)
Values other than undefined, null, integer numbers, and integer strings\n(e.g., '1') are deprecated as value for the code parameter in\nprocess.exit() and as value to assign to process.exitCode.
'1'
code
process.exit()
process.exitCode
The --trace-atomics-wait flag is deprecated.
--trace-atomics-wait
The well-known MODP groups modp1, modp2, and modp5 are deprecated because\nthey are not secure against practical attacks. See RFC 8247 Section 2.4 for\ndetails.
modp1
modp2
modp5
These groups might be removed in future versions of Node.js. Applications that\nrely on these groups should evaluate using stronger MODP groups instead.
Type: Runtime.
The implicit suppression of uncaught exceptions in Node-API callbacks is now\ndeprecated.
Set the flag --force-node-api-uncaught-exceptions-policy to force Node.js\nto emit an 'uncaughtException' event if the exception is not handled in\nNode-API callbacks.
--force-node-api-uncaught-exceptions-policy
'uncaughtException'