Node.js may deprecate APIs when either: (a) use of the API is considered to be unsafe, (b) an improved alternative API has been made available, or (c) breaking changes to the API are expected in a future major release.
Node.js utilizes three kinds of Deprecations:
A Documentation-only deprecation is one that is expressed only within the Node.js API docs. These generate no side-effects while running Node.js.
A Runtime deprecation will, by default, generate a process warning that will be printed to stderr the first time the deprecated API is used. When the --throw-deprecation command-line flag is used, a Runtime deprecation will cause an error to be thrown.
An End-of-Life deprecation is used to identify code that either has been removed or will soon be removed from Node.js.
From time-to-time the deprecation of an API may be reversed. Such action may happen in either a semver-minor or semver-major release. In such situations, this document will be updated with information relevant to the decision. However, the deprecation identifier will not be modified.
Type: Runtime
The OutgoingMessage.prototype.flush() method is deprecated. Use OutgoingMessage.prototype.flushHeaders() instead.
Type: End-of-Life
The _linklist module is deprecated. Please use a userland alternative.
Type: Runtime
The _writableState.buffer property is deprecated. Use the _writableState.getBuffer() method instead.
Type: Documentation-only
The CryptoStream.prototype.readyState property is deprecated and should not be used.
Type: Documentation-only
The Buffer() function and new Buffer() constructor are deprecated due to API usability issues that can potentially lead to accidental security issues.
As an alternative, use of the following methods of constructing Buffer objects is strongly recommended:
Buffer.alloc(size[, fill[, encoding]]) - Create a Buffer with initialized memory.Buffer.allocUnsafe(size) - Create a Buffer with uninitialized memory.Buffer.allocUnsafeSlow(size) - Create a Buffer with uninitialized memory.Buffer.from(array) - Create a Buffer with a copy of array
Buffer.from(arrayBuffer[, byteOffset[, length]]) - Create a Buffer that wraps the given arrayBuffer.Buffer.from(buffer) - Create a Buffer that copies buffer.Buffer.from(string[, encoding]) - Create a Buffer that copies string.Type: Runtime
Within the child_process module's spawn(), fork(), and exec() methods, the options.customFds option is deprecated. The options.stdio option should be used instead.
Type: Runtime
Within the cluster module, the worker.suicide property has been deprecated. Please use worker.exitedAfterDisconnect instead.
Type: Documentation-only
The constants module has been deprecated. When requiring access to constants relevant to specific Node.js builtin modules, developers should instead refer to the constants property exposed by the relevant module. For instance, require('fs').constants and require('os').constants.
Type: End-of-life
Use of the crypto.pbkdf2() API without specifying a digest was deprecated in Node.js 6.0 because the method defaulted to using the non-recommended 'SHA1' digest. Previously, a deprecation warning was printed. Starting in Node.js 8.0.0, calling crypto.pbkdf2() or crypto.pbkdf2Sync() with an undefined digest will throw a TypeError.
Type: Runtime
The crypto.createCredentials() API is deprecated. Please use tls.createSecureContext() instead.
Type: Runtime
The crypto.Credentials class is deprecated. Please use tls.SecureContext instead.
Type: Runtime
Domain.dispose() is deprecated. Recover from failed I/O actions explicitly via error event handlers set on the domain instead.
Type: Runtime
Calling an asynchronous function without a callback is deprecated.
Type: End-of-Life
The fs.read() legacy String interface is deprecated. Use the Buffer API as mentioned in the documentation instead.
Type: End-of-Life
The fs.readSync() legacy String interface is deprecated. Use the Buffer API as mentioned in the documentation instead.
Type: Runtime
The GLOBAL and root aliases for the global property have been deprecated and should no longer be used.
Type: Runtime
The Intl.v8BreakIterator is deprecated and will be removed or replaced soon.
Type: Runtime
Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
Type: Runtime
In certain cases, require('.') may resolve outside the package directory. This behavior is deprecated and will be removed in a future major Node.js release.
Type: Runtime
The Server.connections property is deprecated. Please use the Server.getConnections() method instead.
Type: Runtime
The Server.listenFD() method is deprecated. Please use Server.listen({fd: <number>}) instead.
Type: Runtime
The os.tmpDir() API is deprecated. Please use os.tmpdir() instead.
Type: Runtime
The os.getNetworkInterfaces() method is deprecated. Please use the os.networkInterfaces property instead.
Type: Runtime
The REPLServer.prototype.convertToContext() API is deprecated and should not be used.
Type: Runtime
The sys module is deprecated. Please use the util module instead.
Type: Runtime
The util.print() API is deprecated. Please use console.log() instead.
Type: Runtime
The util.puts() API is deprecated. Please use console.log() instead.
Type: Runtime
The util.debug() API is deprecated. Please use console.error() instead.
Type: Runtime
The util.error() API is deprecated. Please use console.error() instead.
Type: Documentation-only
The SlowBuffer class has been deprecated. Please use Buffer.allocUnsafeSlow(size) instead.
Type: Documentation-only
The ecdh.setPublicKey() method is now deprecated as its inclusion in the API is not useful.
Type: Documentation-only
The domain module is deprecated and should not be used.
Type: Documentation-only
The EventEmitter.listenerCount(emitter, eventName) API has been deprecated. Please use emitter.listenerCount(eventName) instead.
Type: Documentation-only
The fs.exists(path, callback) API has been deprecated. Please use fs.stat() or fs.access() instead.
Type: Documentation-only
The fs.lchmod(path, mode, callback) API has been deprecated.
Type: Documentation-only
The fs.lchmodSync(path, mode) API has been deprecated.
Type: Documentation-only
The fs.lchown(path, uid, gid, callback) API has been deprecated.
Type: Documentation-only
The fs.lchownSync(path, uid, gid) API has been deprecated.
Type: Documentation-only
The require.extensions property has been deprecated.
Type: Documentation-only
The punycode module has been deprecated. Please use a userland alternative instead.
Type: Documentation-only
The NODE_REPL_HISTORY_FILE environment variable has been deprecated.
Type: Documentation-only
The tls.CryptoStream class has been deprecated. Please use tls.TLSSocket instead.
Type: Documentation-only
The tls.SecurePair class has been deprecated. Please use tls.TLSSocket instead.
Type: Documentation-only
The util.isArray() API has been deprecated. Please use Array.isArray() instead.
Type: Documentation-only
The util.isBoolean() API has been deprecated.
Type: Documentation-only
The util.isBuffer() API has been deprecated. Please use Buffer.isBuffer() instead.
Type: Documentation-only
The util.isDate() API has been deprecated.
Type: Documentation-only
The util.isError() API has been deprecated.
Type: Documentation-only
The util.isFunction() API has been deprecated.
Type: Documentation-only
The util.isNull() API has been deprecated.
Type: Documentation-only
The util.isNullOrUndefined() API has been deprecated.
Type: Documentation-only
The util.isNumber() API has been deprecated.
Type: Documentation-only
The util.isObject() API has been deprecated.
Type: Documentation-only
The util.isPrimitive() API has been deprecated.
Type: Documentation-only
The util.isRegExp() API has been deprecated.
Type: Documentation-only
The util.isString() API has been deprecated.
Type: Documentation-only
The util.isSymbol() API has been deprecated.
Type: Documentation-only
The util.isUndefined() API has been deprecated.
Type: Documentation-only
The util.log() API has been deprecated.
Type: Documentation-only
The util._extend() API has been deprecated.
Type: Runtime
The fs.SyncWriteStream class was never intended to be a publicly accessible API. No alternative API is available. Please use a userland alternative.
Type: Runtime
--debug activates the legacy V8 debugger interface, which has been removed as of V8 5.8. It is replaced by Inspector which is activated with --inspect instead.
Type: Documentation-only
The http module ServerResponse.prototype.writeHeader() API has been deprecated. Please use ServerResponse.prototype.writeHead() instead.
Note: The ServerResponse.prototype.writeHeader() method was never documented as an officially supported API.
Type: Runtime
The tls.createSecurePair() API was deprecated in documentation in Node.js 0.11.3. Users should use tls.Socket instead.
Type: Documentation-only
The repl module's REPL_MODE_MAGIC constant, used for replMode option, has been deprecated. Its behavior has been functionally identical to that of REPL_MODE_SLOPPY since Node.js v6.0.0, when V8 5.0 was imported. Please use REPL_MODE_SLOPPY instead.
The NODE_REPL_MODE environment variable is used to set the underlying replMode of an interactive node session. Its default value, magic, is similarly deprecated in favor of sloppy.
Type: Documentation-only
The http module outgoingMessage._headers and outgoingMessage._headerNames properties have been deprecated. Please instead use one of the public methods (e.g. outgoingMessage.getHeader(), outgoingMessage.getHeaders(), outgoingMessage.getHeaderNames(), outgoingMessage.hasHeader(), outgoingMessage.removeHeader(), outgoingMessage.setHeader()) for working with outgoing headers.
Note: outgoingMessage._headers and outgoingMessage._headerNames were never documented as officially supported properties.
Type: Documentation-only
The http module OutgoingMessage.prototype._renderHeaders() API has been deprecated.
Note: OutgoingMessage.prototype._renderHeaders was never documented as an officially supported API.
Type: Runtime
node debug corresponds to the legacy CLI debugger which has been replaced with a V8-inspector based CLI debugger available through node inspect.
Type: Documentation-only
The DebugContext will be removed in V8 soon and will not be available in Node 10+.
Note: DebugContext was an experimental API.
Type: Runtime
async_hooks.currentId() was renamed to async_hooks.executionAsyncId() for clarity.
Note: change was made while async_hooks was an experimental API.
Type: Runtime
async_hooks.triggerId() was renamed to async_hooks.triggerAsyncId() for clarity.
Note: change was made while async_hooks was an experimental API.
Type: Runtime
async_hooks.AsyncResource.triggerId() was renamed to async_hooks.AsyncResource.triggerAsyncId() for clarity.
Note: change was made while async_hooks was an experimental API.
Type: Documentation-only
tls.parseCertString() is a trivial parsing helper that was made public by mistake. This function can usually be replaced with:
const querystring = require('querystring');
querystring.parse(str, '\n', '=');
Note: This function is not completely equivalent to querystring.parse(). One difference is that querystring.parse() does url decoding:
> querystring.parse('%E5%A5%BD=1', '\n', '=');
{ '好': '1' }
> tls.parseCertString('%E5%A5%BD=1');
{ '%E5%A5%BD': '1' }
Type: Documentation-only
Using a property named inspect on an object to specify a custom inspection function for util.inspect() is deprecated. Use util.inspect.custom instead. For backwards compatibility with Node.js prior to version 6.4.0, both may be specified.
Type: Runtime
The AsyncHooks Sensitive API was never documented and had various of minor issues, see https://github.com/nodejs/node/issues/15572. Use the AsyncResource API instead.
Type: Runtime
runInAsyncIdScope doesn't emit the before or after event and can thus cause a lot of issues. See https://github.com/nodejs/node/issues/14328 for more details.
Type: Documentation-only
Importing assert directly is not recommended as the exposed functions will use loose equality checks. Use require('assert').strict instead. The API is the same as the legacy assert but it will always use strict equality checks.
Type: Runtime
The embedded API provided by AsyncHooks exposes emit<Before,After> methods which are very easy to use incorrectly which can lead to unrecoverable errors.
Use asyncResource.runInAsyncScope() API instead which provides a much safer, and more convenient, alternative. See https://github.com/nodejs/node/pull/18513 for more details.
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https://nodejs.org/dist/latest-v8.x/docs/api/deprecations.html