node/doc/api/deprecations.md

Deprecated APIs

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:

• Documentation-only
• Runtime
• End-of-Life

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.

Un-deprecation

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.

List of Deprecated APIs

DEP0001: http.OutgoingMessage.prototype.flush

Type: Runtime

The OutgoingMessage.prototype.flush() method is deprecated. Use OutgoingMessage.prototype.flushHeaders() instead.

DEP0002: require('_linklist')

Type: Runtime

The _linklist module is deprecated. Please use a userland alternative.

DEP0003: _writableState.buffer

Type: Runtime

The _writableState.buffer property is deprecated. Use the _writableState.getBuffer() method instead.

DEP0004: CryptoStream.prototype.readyState

Type: Documentation-only

The CryptoStream.prototype.readyState property is deprecated and should not be used.

DEP0005: Buffer() constructor

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.

DEP0006: child_process options.customFds

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.

DEP0007: cluster worker.suicide

Type: Runtime

Within the cluster module, the worker.suicide property has been deprecated. Please use worker.exitedAfterDisconnect instead.

DEP0008: require('constants')

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.

DEP0009: crypto.pbkdf2 without digest

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-recommendend '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.

DEP0010: crypto.createCredentials

Type: Runtime

The crypto.createCredentials() API is deprecated. Please use tls.createSecureContext() instead.

DEP0011: crypto.Credentials

Type: Runtime

The crypto.Credentials class is deprecated. Please use tls.SecureContext instead.

DEP0012: Domain.dispose

Type: Runtime

Domain.dispose() is deprecated. Recover from failed I/O actions explicitly via error event handlers set on the domain instead.

DEP0013: fs async function without callback

Type: Runtime

Calling an asynchronous function without a callback is deprecated.

DEP0014: fs.read legacy String interface

Type: End-of-Life

The fs.read() legacy String interface is deprecated. Use the Buffer API as mentioned in the documentation instead.

DEP0015: fs.readSync legacy String interface

Type: End-of-Life

The fs.readSync() legacy String interface is deprecated. Use the Buffer API as mentioned in the documentation instead.

DEP0016: GLOBAL/root

Type: Runtime

The GLOBAL and root aliases for the global property have been deprecated and should no longer be used.

DEP0017: Intl.v8BreakIterator

Type: Runtime

The Intl.v8BreakIterator is deprecated and will be removed or replaced soon.

DEP0018: Unhandled promise rejections

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.

DEP0019: require('.') resolved outside directory

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.

DEP0020: Server.connections

Type: Runtime

The Server.connections property is deprecated. Please use the Server.getConnections() method instead.

DEP0021: Server.listenFD

Type: Runtime

The Server.listenFD() method is deprecated. Please use Server.listen({fd: <number>}) instead.

DEP0022: os.tmpDir()

Type: Runtime

The os.tmpDir() API is deprecated. Please use os.tmpdir() instead.

DEP0023: os.getNetworkInterfaces()

Type: Runtime

The os.getNetworkInterfaces() method is deprecated. Please use the os.networkInterfaces property instead.

DEP0024: REPLServer.prototype.convertToContext()

Type: Runtime

The REPLServer.prototype.convertToContext() API is deprecated and should not be used.

DEP0025: require('sys')

Type: Runtime

The sys module is deprecated. Please use the util module instead.

DEP0026: util.print()

Type: Runtime

The util.print() API is deprecated. Please use console.log() instead.

DEP0027: util.puts()

Type: Runtime

The util.puts() API is deprecated. Please use console.log() instead.

DEP0028: util.debug()

Type: Runtime

The util.debug() API is deprecated. Please use console.error() instead.

DEP0029: util.error()

Type: Runtime

The util.error() API is deprecated. Please use console.error() instead.

DEP0030: SlowBuffer

Type: Documentation-only

The SlowBuffer class has been deprecated. Please use Buffer.allocUnsafeSlow(size) instead.

DEP0031: ecdh.setPublicKey()

Type: Documentation-only

The ecdh.setPublicKey() method is now deprecated as its inclusion in the API is not useful.

DEP0032: domain module

Type: Documentation-only

The domain module is deprecated and should not be used.

DEP0033: EventEmitter.listenerCount()

Type: Documentation-only

The EventEmitter.listenerCount(emitter, eventName) API has been deprecated. Please use emitter.listenerCount(eventName) instead.

DEP0034: fs.exists(path, callback)

Type: Documentation-only

The fs.exists(path, callback) API has been deprecated. Please use fs.stat() or fs.access() instead.

DEP0035: fs.lchmod(path, mode, callback)

Type: Documentation-only

The fs.lchmod(path, mode, callback) API has been deprecated.

DEP0036: fs.lchmodSync(path, mode)

Type: Documentation-only

The fs.lchmodSync(path, mode) API has been deprecated.

DEP0037: fs.lchown(path, uid, gid, callback)

Type: Documentation-only

The fs.lchown(path, uid, gid, callback) API has been deprecated.

DEP0038: fs.lchownSync(path, uid, gid)

Type: Documentation-only

The fs.lchownSync(path, uid, gid) API has been deprecated.

DEP0039: require.extensions

Type: Documentation-only

The require.extensions property has been deprecated.

DEP0040: punycode module

Type: Documentation-only

The punycode module has been deprecated. Please use a userland alternative instead.

DEP0041: NODE_REPL_HISTORY_FILE environment variable

Type: Documentation-only

The NODE_REPL_HISTORY_FILE environment variable has been deprecated.

DEP0042: tls.CryptoStream

Type: Documentation-only

The tls.CryptoStream class has been deprecated. Please use tls.TLSSocket instead.

DEP0043: tls.SecurePair

Type: Documentation-only

The tls.SecurePair class has been deprecated. Please use tls.TLSSocket instead.

DEP0044: util.isArray()

Type: Documentation-only

The util.isArray() API has been deprecated. Please use Array.isArray() instead.

DEP0045: util.isBoolean()

Type: Documentation-only

The util.isBoolean() API has been deprecated.

DEP0046: util.isBuffer()

Type: Documentation-only

The util.isBuffer() API has been deprecated. Please use Buffer.isBuffer() instead.

DEP0047: util.isDate()

Type: Documentation-only

The util.isDate() API has been deprecated.

DEP0048: util.isError()

Type: Documentation-only

The util.isError() API has been deprecated.

DEP0049: util.isFunction()

Type: Documentation-only

The util.isFunction() API has been deprecated.

DEP0050: util.isNull()

Type: Documentation-only

The util.isNull() API has been deprecated.

DEP0051: util.isNullOrUndefined()

Type: Documentation-only

The util.isNullOrUndefined() API has been deprecated.

DEP0052: util.isNumber()

Type: Documentation-only

The util.isNumber() API has been deprecated.

DEP0053 util.isObject()

Type: Documentation-only

The util.isObject() API has been deprecated.

DEP0054: util.isPrimitive()

Type: Documentation-only

The util.isPrimitive() API has been deprecated.

DEP0055: util.isRegExp()

Type: Documentation-only

The util.isRegExp() API has been deprecated.

DEP0056: util.isString()

Type: Documentation-only

The util.isString() API has been deprecated.

DEP0057: util.isSymbol()

Type: Documentation-only

The util.isSymbol() API has been deprecated.

DEP0058: util.isUndefined()

Type: Documentation-only

The util.isUndefined() API has been deprecated.

DEP0059: util.log()

Type: Documentation-only

The util.log() API has been deprecated.

DEP0060: util._extend()

Type: Documentation-only

The util._extend() API has been deprecated.

DEP0061: fs.SyncWriteStream

Type: Documentation-only

The fs.SyncWriteStream class was never intended to be a publicly accessible API.

DEP0062: node --debug

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.