# Deprecated APIs Node.js may deprecate APIs for any of the following reasons: * Use of the API is unsafe. * An improved alternative API is available. * 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. Some Documentation-only deprecations trigger a runtime warning when launched with [`--pending-deprecation`][] flag (or its alternative, `NODE_PENDING_DEPRECATION=1` environment variable), similarly to Runtime deprecations below. Documentation-only deprecations that support that flag are explicitly labeled as such in the [list of Deprecated APIs](#deprecations_list_of_deprecated_apis). 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 when functionality is or will soon be removed from Node.js. ## Revoking deprecations Occasionally, the deprecation of an API may be reversed. 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: End-of-Life `OutgoingMessage.prototype.flush()` has been removed. Use `OutgoingMessage.prototype.flushHeaders()` instead. ### DEP0002: `require('_linklist')` Type: End-of-Life The `_linklist` module is deprecated. Please use a userland alternative. ### DEP0003: `_writableState.buffer` Type: End-of-Life The `_writableState.buffer` has been removed. Use `_writableState.getBuffer()` instead. ### DEP0004: `CryptoStream.prototype.readyState` Type: End-of-Life The `CryptoStream.prototype.readyState` property was removed. ### DEP0005: `Buffer()` constructor Type: Runtime (supports [`--pending-deprecation`][]) The `Buffer()` function and `new Buffer()` constructor are deprecated due to API usability issues that can lead to accidental security issues. As an alternative, use one of the following methods of constructing `Buffer` objects: * [`Buffer.alloc(size[, fill[, encoding]])`][alloc]: Create a `Buffer` with *initialized* memory. * [`Buffer.allocUnsafe(size)`][alloc_unsafe_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]])`][from_arraybuffer] - Create a `Buffer` that wraps the given `arrayBuffer`. * [`Buffer.from(buffer)`][]: Create a `Buffer` that copies `buffer`. * [`Buffer.from(string[, encoding])`][from_string_encoding]: Create a `Buffer` that copies `string`. Without `--pending-deprecation`, runtime warnings occur only for code not in `node_modules`. This means there will not be deprecation warnings for `Buffer()` usage in dependencies. With `--pending-deprecation`, a runtime warning results no matter where the `Buffer()` usage occurs. ### DEP0006: `child_process` `options.customFds` Type: End-of-Life 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: Replace `cluster` `worker.suicide` with `worker.exitedAfterDisconnect` Type: End-of-Life In an earlier version of the Node.js `cluster`, a boolean property with the name `suicide` was added to the `Worker` object. The intent of this property was to provide an indication of how and why the `Worker` instance exited. In Node.js 6.0.0, the old property was deprecated and replaced with a new [`worker.exitedAfterDisconnect`][] property. The old property name did not precisely describe the actual semantics and was unnecessarily emotion-laden. ### DEP0008: `require('constants')` Type: Documentation-only The `constants` module is 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-recommended `'SHA1'` digest. Previously, a deprecation warning was printed. Starting in Node.js 8.0.0, calling `crypto.pbkdf2()` or `crypto.pbkdf2Sync()` with `digest` set to `undefined` will throw a `TypeError`. Beginning in Node.js v11.0.0, calling these functions with `digest` set to `null` would print a deprecation warning to align with the behavior when `digest` is `undefined`. Now, however, passing either `undefined` or `null` will throw a `TypeError`. ### DEP0010: `crypto.createCredentials` Type: End-of-Life The `crypto.createCredentials()` API was removed. Please use [`tls.createSecureContext()`][] instead. ### DEP0011: `crypto.Credentials` Type: End-of-Life The `crypto.Credentials` class was removed. Please use [`tls.SecureContext`][] instead. ### DEP0012: `Domain.dispose` Type: End-of-Life `Domain.dispose()` has been removed. Recover from failed I/O actions explicitly via error event handlers set on the domain instead. ### DEP0013: `fs` asynchronous function without callback Type: End-of-Life Calling an asynchronous function without a callback throws a `TypeError` in Node.js 10.0.0 onwards. See . ### 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: End-of-Life The `GLOBAL` and `root` aliases for the `global` property were deprecated in Node.js 6.0.0 and have since been removed. ### DEP0017: `Intl.v8BreakIterator` Type: End-of-Life `Intl.v8BreakIterator` was a non-standard extension and has been removed. See [`Intl.Segmenter`](https://github.com/tc39/proposal-intl-segmenter). ### 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: End-of-Life In certain cases, `require('.')` could resolve outside the package directory. This behavior has been removed. ### DEP0020: `Server.connections` Type: End-of-Life The `Server.connections` property was deprecated in Node.js v0.9.7 and has been removed. Please use the [`Server.getConnections()`][] method instead. ### DEP0021: `Server.listenFD` Type: End-of-Life The `Server.listenFD()` method was deprecated and removed. Please use [`Server.listen({fd: })`][] instead. ### DEP0022: `os.tmpDir()` Type: End-of-Life The `os.tmpDir()` API was deprecated in Node.js 7.0.0 and has since been removed. Please use [`os.tmpdir()`][] instead. ### DEP0023: `os.getNetworkInterfaces()` Type: End-of-Life The `os.getNetworkInterfaces()` method is deprecated. Please use the [`os.networkInterfaces()`][] method instead. ### DEP0024: `REPLServer.prototype.convertToContext()` Type: End-of-Life The `REPLServer.prototype.convertToContext()` API has been removed. ### DEP0025: `require('sys')` Type: Runtime The `sys` module is deprecated. Please use the [`util`][] module instead. ### DEP0026: `util.print()` Type: End-of-Life `util.print()` has been removed. Please use [`console.log()`][] instead. ### DEP0027: `util.puts()` Type: End-of-Life `util.puts()` has been removed. Please use [`console.log()`][] instead. ### DEP0028: `util.debug()` Type: End-of-Life `util.debug()` has been removed. Please use [`console.error()`][] instead. ### DEP0029: `util.error()` Type: End-of-Life `util.error()` has been removed. Please use [`console.error()`][] instead. ### DEP0030: `SlowBuffer` Type: Documentation-only The [`SlowBuffer`][] class is 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 is deprecated. Please use [`emitter.listenerCount(eventName)`][] instead. ### DEP0034: `fs.exists(path, callback)` Type: Documentation-only The [`fs.exists(path, callback)`][] API is 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 is deprecated. ### DEP0036: `fs.lchmodSync(path, mode)` Type: Documentation-only The [`fs.lchmodSync(path, mode)`][] API is deprecated. ### DEP0037: `fs.lchown(path, uid, gid, callback)` Type: Deprecation revoked The [`fs.lchown(path, uid, gid, callback)`][] API was deprecated. The deprecation was revoked because the requisite supporting APIs were added in libuv. ### DEP0038: `fs.lchownSync(path, uid, gid)` Type: Deprecation revoked The [`fs.lchownSync(path, uid, gid)`][] API was deprecated. The deprecation was revoked because the requisite supporting APIs were added in libuv. ### DEP0039: `require.extensions` Type: Documentation-only The [`require.extensions`][] property is deprecated. ### DEP0040: `punycode` module Type: Documentation-only The [`punycode`][] module is deprecated. Please use a userland alternative instead. ### DEP0041: `NODE_REPL_HISTORY_FILE` environment variable Type: End-of-Life The `NODE_REPL_HISTORY_FILE` environment variable was removed. Please use `NODE_REPL_HISTORY` instead. ### DEP0042: `tls.CryptoStream` Type: End-of-Life The [`tls.CryptoStream`][] class was removed. Please use [`tls.TLSSocket`][] instead. ### DEP0043: `tls.SecurePair` Type: Documentation-only The [`tls.SecurePair`][] class is deprecated. Please use [`tls.TLSSocket`][] instead. ### DEP0044: `util.isArray()` Type: Documentation-only The [`util.isArray()`][] API is deprecated. Please use `Array.isArray()` instead. ### DEP0045: `util.isBoolean()` Type: Documentation-only The [`util.isBoolean()`][] API is deprecated. ### DEP0046: `util.isBuffer()` Type: Documentation-only The [`util.isBuffer()`][] API is deprecated. Please use [`Buffer.isBuffer()`][] instead. ### DEP0047: `util.isDate()` Type: Documentation-only The [`util.isDate()`][] API is deprecated. ### DEP0048: `util.isError()` Type: Documentation-only The [`util.isError()`][] API is deprecated. ### DEP0049: `util.isFunction()` Type: Documentation-only The [`util.isFunction()`][] API is deprecated. ### DEP0050: `util.isNull()` Type: Documentation-only The [`util.isNull()`][] API is deprecated. ### DEP0051: `util.isNullOrUndefined()` Type: Documentation-only The [`util.isNullOrUndefined()`][] API is deprecated. ### DEP0052: `util.isNumber()` Type: Documentation-only The [`util.isNumber()`][] API is deprecated. ### DEP0053 `util.isObject()` Type: Documentation-only The [`util.isObject()`][] API is deprecated. ### DEP0054: `util.isPrimitive()` Type: Documentation-only The [`util.isPrimitive()`][] API is deprecated. ### DEP0055: `util.isRegExp()` Type: Documentation-only The [`util.isRegExp()`][] API is deprecated. ### DEP0056: `util.isString()` Type: Documentation-only The [`util.isString()`][] API is deprecated. ### DEP0057: `util.isSymbol()` Type: Documentation-only The [`util.isSymbol()`][] API is deprecated. ### DEP0058: `util.isUndefined()` Type: Documentation-only The [`util.isUndefined()`][] API is deprecated. ### DEP0059: `util.log()` Type: Documentation-only The [`util.log()`][] API is deprecated. ### DEP0060: `util._extend()` Type: Documentation-only The [`util._extend()`][] API is deprecated. ### DEP0061: `fs.SyncWriteStream` Type: End-of-Life The `fs.SyncWriteStream` class was never intended to be a publicly accessible API and has been removed. No alternative API is available. Please use a userland alternative. ### DEP0062: `node --debug` Type: End-of-Life `--debug` activates the legacy V8 debugger interface, which was removed as of V8 5.8. It is replaced by Inspector which is activated with `--inspect` instead. ### DEP0063: `ServerResponse.prototype.writeHeader()` Type: Documentation-only The `http` module `ServerResponse.prototype.writeHeader()` API is deprecated. Please use `ServerResponse.prototype.writeHead()` instead. The `ServerResponse.prototype.writeHeader()` method was never documented as an officially supported API. ### DEP0064: `tls.createSecurePair()` Type: Runtime The `tls.createSecurePair()` API was deprecated in documentation in Node.js 0.11.3. Users should use `tls.Socket` instead. ### DEP0065: `repl.REPL_MODE_MAGIC` and `NODE_REPL_MODE=magic` Type: End-of-Life The `repl` module's `REPL_MODE_MAGIC` constant, used for `replMode` option, has been removed. Its behavior has been functionally identical to that of `REPL_MODE_SLOPPY` since Node.js 6.0.0, 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 value, `magic`, is also removed. Please use `sloppy` instead. ### DEP0066: `OutgoingMessage.prototype._headers, OutgoingMessage.prototype._headerNames` Type: Runtime The `http` module `OutgoingMessage.prototype._headers` and `OutgoingMessage.prototype._headerNames` properties are deprecated. Use one of the public methods (e.g. `OutgoingMessage.prototype.getHeader()`, `OutgoingMessage.prototype.getHeaders()`, `OutgoingMessage.prototype.getHeaderNames()`, `OutgoingMessage.prototype.hasHeader()`, `OutgoingMessage.prototype.removeHeader()`, `OutgoingMessage.prototype.setHeader()`) for working with outgoing headers. The `OutgoingMessage.prototype._headers` and `OutgoingMessage.prototype._headerNames` properties were never documented as officially supported properties. ### DEP0067: `OutgoingMessage.prototype._renderHeaders` Type: Documentation-only The `http` module `OutgoingMessage.prototype._renderHeaders()` API is deprecated. The `OutgoingMessage.prototype._renderHeaders` property was never documented as an officially supported API. ### DEP0068: `node debug` Type: End-of-Life `node debug` corresponds to the legacy CLI debugger which has been replaced with a V8-inspector based CLI debugger available through `node inspect`. ### DEP0069: `vm.runInDebugContext(string)` Type: End-of-Life DebugContext has been removed in V8 and is not available in Node.js 10+. DebugContext was an experimental API. ### DEP0070: `async_hooks.currentId()` Type: End-of-Life `async_hooks.currentId()` was renamed to `async_hooks.executionAsyncId()` for clarity. This change was made while `async_hooks` was an experimental API. ### DEP0071: `async_hooks.triggerId()` Type: End-of-Life `async_hooks.triggerId()` was renamed to `async_hooks.triggerAsyncId()` for clarity. This change was made while `async_hooks` was an experimental API. ### DEP0072: `async_hooks.AsyncResource.triggerId()` Type: End-of-Life `async_hooks.AsyncResource.triggerId()` was renamed to `async_hooks.AsyncResource.triggerAsyncId()` for clarity. This change was made while `async_hooks` was an experimental API. ### DEP0073: Several internal properties of `net.Server` Type: End-of-Life Accessing several internal, undocumented properties of `net.Server` instances with inappropriate names is deprecated. As the original API was undocumented and not generally useful for non-internal code, no replacement API is provided. ### DEP0074: `REPLServer.bufferedCommand` Type: End-of-Life The `REPLServer.bufferedCommand` property was deprecated in favor of [`REPLServer.clearBufferedCommand()`][]. ### DEP0075: `REPLServer.parseREPLKeyword()` Type: End-of-Life `REPLServer.parseREPLKeyword()` was removed from userland visibility. ### DEP0076: `tls.parseCertString()` Type: Runtime `tls.parseCertString()` is a trivial parsing helper that was made public by mistake. This function can usually be replaced with: ```js const querystring = require('querystring'); querystring.parse(str, '\n', '='); ``` This function is not completely equivalent to `querystring.parse()`. One difference is that `querystring.parse()` does url decoding: ```console > querystring.parse('%E5%A5%BD=1', '\n', '='); { '好': '1' } > tls.parseCertString('%E5%A5%BD=1'); { '%E5%A5%BD': '1' } ``` ### DEP0077: `Module._debug()` Type: Runtime `Module._debug()` is deprecated. The `Module._debug()` function was never documented as an officially supported API. ### DEP0078: `REPLServer.turnOffEditorMode()` Type: End-of-Life `REPLServer.turnOffEditorMode()` was removed from userland visibility. ### DEP0079: Custom inspection function on objects via `.inspect()` Type: End-of-Life 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 backward compatibility with Node.js prior to version 6.4.0, both may be specified. ### DEP0080: `path._makeLong()` Type: Documentation-only The internal `path._makeLong()` was not intended for public use. However, userland modules have found it useful. The internal API is deprecated and replaced with an identical, public `path.toNamespacedPath()` method. ### DEP0081: `fs.truncate()` using a file descriptor Type: Runtime `fs.truncate()` `fs.truncateSync()` usage with a file descriptor is deprecated. Please use `fs.ftruncate()` or `fs.ftruncateSync()` to work with file descriptors. ### DEP0082: `REPLServer.prototype.memory()` Type: End-of-Life `REPLServer.prototype.memory()` is only necessary for the internal mechanics of the `REPLServer` itself. Do not use this function. ### DEP0083: Disabling ECDH by setting `ecdhCurve` to `false` Type: End-of-Life. The `ecdhCurve` option to `tls.createSecureContext()` and `tls.TLSSocket` could be set to `false` to disable ECDH entirely on the server only. This mode was deprecated in preparation for migrating to OpenSSL 1.1.0 and consistency with the client and is now unsupported. Use the `ciphers` parameter instead. ### DEP0084: requiring bundled internal dependencies Type: End-of-Life Since Node.js versions 4.4.0 and 5.2.0, several modules only intended for internal usage were mistakenly exposed to user code through `require()`. These modules were: * `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` (from 7.6.0) * `node-inspect/lib/internal/inspect_client` (from 7.6.0) * `node-inspect/lib/internal/inspect_repl` (from 7.6.0) The `v8/*` modules do not have any exports, and if not imported in a specific order would in fact throw errors. As such there are virtually no legitimate use cases for importing them through `require()`. On the other hand, `node-inspect` may be installed locally through a package manager, as it is published on the npm registry under the same name. No source code modification is necessary if that is done. ### DEP0085: AsyncHooks sensitive API Type: End-of-Life The AsyncHooks sensitive API was never documented and had various minor issues. Use the `AsyncResource` API instead. See . ### DEP0086: Remove `runInAsyncIdScope` Type: End-of-Life `runInAsyncIdScope` doesn't emit the `'before'` or `'after'` event and can thus cause a lot of issues. See . ### DEP0089: `require('assert')` Type: Deprecation revoked Importing assert directly was not recommended as the exposed functions use loose equality checks. The deprecation was revoked because use of the `assert` module is not discouraged, and the deprecation caused end user confusion. ### DEP0090: Invalid GCM authentication tag lengths Type: End-of-Life Node.js used to support all GCM authentication tag lengths which are accepted by OpenSSL when calling [`decipher.setAuthTag()`][]. Beginning with Node.js v11.0.0, only authentication tag lengths of 128, 120, 112, 104, 96, 64, and 32 bits are allowed. Authentication tags of other lengths are invalid per [NIST SP 800-38D][]. ### DEP0091: `crypto.DEFAULT_ENCODING` Type: Runtime The [`crypto.DEFAULT_ENCODING`][] property is deprecated. ### DEP0092: Top-level `this` bound to `module.exports` Type: Documentation-only Assigning properties to the top-level `this` as an alternative to `module.exports` is deprecated. Developers should use `exports` or `module.exports` instead. ### DEP0093: `crypto.fips` is deprecated and replaced. Type: Documentation-only The [`crypto.fips`][] property is deprecated. Please use `crypto.setFips()` and `crypto.getFips()` instead. ### DEP0094: Using `assert.fail()` with more than one argument. Type: Runtime Using `assert.fail()` with more than one argument is deprecated. Use `assert.fail()` with only one argument or use a different `assert` module method. ### DEP0095: `timers.enroll()` Type: Runtime `timers.enroll()` is deprecated. Please use the publicly documented [`setTimeout()`][] or [`setInterval()`][] instead. ### DEP0096: `timers.unenroll()` Type: Runtime `timers.unenroll()` is deprecated. Please use the publicly documented [`clearTimeout()`][] or [`clearInterval()`][] instead. ### DEP0097: `MakeCallback` with `domain` property Type: Runtime Users of `MakeCallback` that add the `domain` property to carry context, should start using the `async_context` variant of `MakeCallback` or `CallbackScope`, or the high-level `AsyncResource` class. ### DEP0098: AsyncHooks embedder `AsyncResource.emitBefore` and `AsyncResource.emitAfter` APIs Type: End-of-Life The embedded API provided by AsyncHooks exposes `.emitBefore()` and `.emitAfter()` 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 . ### DEP0099: Async context-unaware `node::MakeCallback` C++ APIs Type: Compile-time Certain versions of `node::MakeCallback` APIs available to native modules are deprecated. Please use the versions of the API that accept an `async_context` parameter. ### DEP0100: `process.assert()` Type: Runtime `process.assert()` is deprecated. Please use the [`assert`][] module instead. This was never a documented feature. ### DEP0101: `--with-lttng` Type: End-of-Life The `--with-lttng` compile-time option has been removed. ### DEP0102: Using `noAssert` in `Buffer#(read|write)` operations. Type: End-of-Life Using the `noAssert` argument has no functionality anymore. All input is going to be verified, no matter if it is set to true or not. Skipping the verification could lead to hard to find errors and crashes. ### DEP0103: `process.binding('util').is[...]` typechecks Type: Documentation-only (supports [`--pending-deprecation`][]) Using `process.binding()` in general should be avoided. The type checking methods in particular can be replaced by using [`util.types`][]. This deprecation has been superseded by the deprecation of the `process.binding()` API ([DEP0111](#DEP0111)). ### DEP0104: `process.env` string coercion Type: Documentation-only (supports [`--pending-deprecation`][]) When assigning a non-string property to [`process.env`][], the assigned value is implicitly converted to a string. This behavior is deprecated if the assigned value is not a string, boolean, or number. In the future, such assignment may result in a thrown error. Please convert the property to a string before assigning it to `process.env`. ### DEP0105: `decipher.finaltol` Type: End-of-Life `decipher.finaltol()` has never been documented and was an alias for [`decipher.final()`][]. This API has been removed, and it is recommended to use [`decipher.final()`][] instead. ### DEP0106: `crypto.createCipher` and `crypto.createDecipher` Type: Runtime Using [`crypto.createCipher()`][] and [`crypto.createDecipher()`][] should be avoided as they use a weak key derivation function (MD5 with no salt) and static initialization vectors. It is recommended to derive a key using [`crypto.pbkdf2()`][] or [`crypto.scrypt()`][] and to use [`crypto.createCipheriv()`][] and [`crypto.createDecipheriv()`][] to obtain the [`Cipher`][] and [`Decipher`][] objects respectively. ### DEP0107: `tls.convertNPNProtocols()` Type: End-of-Life This was an undocumented helper function not intended for use outside Node.js core and obsoleted by the removal of NPN (Next Protocol Negotiation) support. ### DEP0108: `zlib.bytesRead` Type: Runtime Deprecated alias for [`zlib.bytesWritten`][]. This original name was chosen because it also made sense to interpret the value as the number of bytes read by the engine, but is inconsistent with other streams in Node.js that expose values under these names. ### DEP0109: `http`, `https`, and `tls` support for invalid URLs Type: Runtime Some previously supported (but strictly invalid) URLs were accepted through the [`http.request()`][], [`http.get()`][], [`https.request()`][], [`https.get()`][], and [`tls.checkServerIdentity()`][] APIs because those were accepted by the legacy `url.parse()` API. The mentioned APIs now use the WHATWG URL parser that requires strictly valid URLs. Passing an invalid URL is deprecated and support will be removed in the future. ### DEP0110: `vm.Script` cached data Type: Documentation-only The `produceCachedData` option is deprecated. Use [`script.createCachedData()`][] instead. ### DEP0111: `process.binding()` Type: Documentation-only (supports [`--pending-deprecation`][]) `process.binding()` is for use by Node.js internal code only. ### DEP0112: `dgram` private APIs Type: Runtime The `dgram` module previously contained several APIs that were never meant to accessed outside of Node.js core: `Socket.prototype._handle`, `Socket.prototype._receiving`, `Socket.prototype._bindState`, `Socket.prototype._queue`, `Socket.prototype._reuseAddr`, `Socket.prototype._healthCheck()`, `Socket.prototype._stopReceiving()`, and `dgram._createSocketHandle()`. ### DEP0113: `Cipher.setAuthTag()`, `Decipher.getAuthTag()` Type: End-of-Life `Cipher.setAuthTag()` and `Decipher.getAuthTag()` are no longer available. They were never documented and would throw when called. ### DEP0114: `crypto._toBuf()` Type: End-of-Life The `crypto._toBuf()` function was not designed to be used by modules outside of Node.js core and was removed. ### DEP0115: `crypto.prng()`, `crypto.pseudoRandomBytes()`, `crypto.rng()` Type: Documentation-only (supports [`--pending-deprecation`][]) In recent versions of Node.js, there is no difference between [`crypto.randomBytes()`][] and `crypto.pseudoRandomBytes()`. The latter is deprecated along with the undocumented aliases `crypto.prng()` and `crypto.rng()` in favor of [`crypto.randomBytes()`][] and may be removed in a future release. ### DEP0116: Legacy URL API Type: Documentation-only The [Legacy URL API][] is deprecated. This includes [`url.format()`][], [`url.parse()`][], [`url.resolve()`][], and the [legacy `urlObject`][]. Please use the [WHATWG URL API][] instead. ### DEP0117: Native crypto handles Type: End-of-Life Previous versions of Node.js exposed handles to internal native objects through the `_handle` property of the `Cipher`, `Decipher`, `DiffieHellman`, `DiffieHellmanGroup`, `ECDH`, `Hash`, `Hmac`, `Sign`, and `Verify` classes. The `_handle` property has been removed because improper use of the native object can lead to crashing the application. ### DEP0118: `dns.lookup()` support for a falsy host name Type: Runtime Previous versions of Node.js supported `dns.lookup()` with a falsy host name like `dns.lookup(false)` due to backward compatibility. This behavior is undocumented and is thought to be unused in real world apps. It will become an error in future versions of Node.js. ### DEP0119: `process.binding('uv').errname()` private API Type: Documentation-only (supports [`--pending-deprecation`][]) `process.binding('uv').errname()` is deprecated. Please use [`util.getSystemErrorName()`][] instead. ### DEP0120: Windows Performance Counter support Type: End-of-Life Windows Performance Counter support has been removed from Node.js. The undocumented `COUNTER_NET_SERVER_CONNECTION()`, `COUNTER_NET_SERVER_CONNECTION_CLOSE()`, `COUNTER_HTTP_SERVER_REQUEST()`, `COUNTER_HTTP_SERVER_RESPONSE()`, `COUNTER_HTTP_CLIENT_REQUEST()`, and `COUNTER_HTTP_CLIENT_RESPONSE()` functions have been deprecated. ### DEP0121: `net._setSimultaneousAccepts()` Type: Runtime The undocumented `net._setSimultaneousAccepts()` function was originally intended for debugging and performance tuning when using the `child_process` and `cluster` modules on Windows. The function is not generally useful and is being removed. See discussion here: ### DEP0122: `tls` `Server.prototype.setOptions()` Type: Runtime Please use `Server.prototype.setSecureContext()` instead. ### DEP0123: setting the TLS ServerName to an IP address Type: Runtime Setting the TLS ServerName to an IP address is not permitted by [RFC 6066][]. This will be ignored in a future version. ### DEP0124: using `REPLServer.rli` Type: End-of-Life This property is a reference to the instance itself. ### DEP0125: `require('_stream_wrap')` Type: Runtime The `_stream_wrap` module is deprecated. ### DEP0126: `timers.active()` Type: Runtime The previously undocumented `timers.active()` is deprecated. Please use the publicly documented [`timeout.refresh()`][] instead. If re-referencing the timeout is necessary, [`timeout.ref()`][] can be used with no performance impact since Node.js 10. ### DEP0127: `timers._unrefActive()` Type: Runtime The previously undocumented and "private" `timers._unrefActive()` is deprecated. Please use the publicly documented [`timeout.refresh()`][] instead. If unreferencing the timeout is necessary, [`timeout.unref()`][] can be used with no performance impact since Node.js 10. ### DEP0128: modules with an invalid `main` entry and an `index.js` file Type: Documentation-only (supports [`--pending-deprecation`][]) Modules that have an invalid `main` entry (e.g., `./does-not-exist.js`) and also have an `index.js` file in the top level directory will resolve the `index.js` file. That is deprecated and is going to throw an error in future Node.js versions. ### DEP0129: `ChildProcess._channel` Type: Runtime The `_channel` property of child process objects returned by `spawn()` and similar functions is not intended for public use. Use `ChildProcess.channel` instead. ### DEP0130: `Module.createRequireFromPath()` Type: Runtime Module.createRequireFromPath() is deprecated. Please use [`module.createRequire()`][] instead. ### DEP0131: Legacy HTTP parser Type: End-of-Life The legacy HTTP parser, used by default in versions of Node.js prior to 12.0.0, is deprecated and has been removed in v13.0.0. Prior to v13.0.0, the `--http-parser=legacy` command-line flag could be used to revert to using the legacy parser. ### DEP0132: `worker.terminate()` with callback Type: Runtime Passing a callback to [`worker.terminate()`][] is deprecated. Use the returned `Promise` instead, or a listener to the worker’s `'exit'` event. ### DEP0133: `http` `connection` Type: Documentation-only Prefer [`response.socket`][] over [`response.connection`][] and [`request.socket`][] over [`request.connection`][]. ### DEP0134: `process._tickCallback` Type: Documentation-only (supports [`--pending-deprecation`][]) The `process._tickCallback` property was never documented as an officially supported API. ### DEP0135: `WriteStream.open()` and `ReadStream.open()` are internal Type: Runtime [`WriteStream.open()`][] and [`ReadStream.open()`][] are undocumented internal APIs that do not make sense to use in userland. File streams should always be opened through their corresponding factory methods [`fs.createWriteStream()`][] and [`fs.createReadStream()`][]) or by passing a file descriptor in options. ### DEP0136: `http` `finished` Type: Documentation-only [`response.finished`][] indicates whether [`response.end()`][] has been called, not whether `'finish'` has been emitted and the underlying data is flushed. Use [`response.writableFinished`][] or [`response.writableEnded`][] accordingly instead to avoid the ambigiuty. To maintain existing behaviour `response.finished` should be replaced with `response.writableEnded`. ### DEP0137: Closing fs.FileHandle on garbage collection Type: Runtime Allowing a [`fs.FileHandle`][] object to be closed on garbage collection is deprecated. In the future, doing so may result in a thrown error that will terminate the process. Please ensure that all `fs.FileHandle` objects are explicitly closed using `FileHandle.prototype.close()` when the `fs.FileHandle` is no longer needed: ```js const fsPromises = require('fs').promises; async function openAndClose() { let filehandle; try { filehandle = await fsPromises.open('thefile.txt', 'r'); } finally { if (filehandle !== undefined) await filehandle.close(); } } ``` ### DEP0138: `process.mainModule` Type: Documentation-only [`process.mainModule`][] is a CommonJS-only feature while `process` global object is shared with non-CommonJS environment. Its use within ECMAScript modules is unsupported. It is deprecated in favor of [`require.main`][], because it serves the same purpose and is only available on CommonJS environment. ### DEP0139: `process.umask()` with no arguments Type: Runtime Calling `process.umask()` with no argument causes the process-wide umask to be written twice. This introduces a race condition between threads, and is a potential security vulnerability. There is no safe, cross-platform alternative API. ### DEP0140: Use `request.destroy()` instead of `request.abort()` Type: Documentation-only Use [`request.destroy()`][] instead of [`request.abort()`][]. ### DEP0141: `repl.inputStream` and `repl.outputStream` Type: Documentation-only (supports [`--pending-deprecation`][]) The `repl` module exported the input and output stream twice. Use `.input` instead of `.inputStream` and `.output` instead of `.outputStream`. ### DEP0142: `repl._builtinLibs` Type: Documentation-only The `repl` module exports a `_builtinLibs` property that contains an array with native modules. It was incomplete so far and instead it's better to rely upon `require('module').builtinModules`. ### DEP0143: `module.parent` Type: Documentation-only (supports [`--pending-deprecation`][]) A CommonJS module can access the first module that required it using `module.parent`. This feature is deprecated because it does not work consistently in the presence of ECMAScript modules and because it gives an inaccurate representation of the CommonJS module graph. Some modules use it to check if they are the entry point of the current process. Instead, it is recommended to compare `require.main` and `module`: ```js if (require.main === module) { // Code section that will run only if current file is the entry point. } ``` When looking for the CommonJS modules that have required the current one, `require.cache` and `module.children` can be used: ```js const moduleParents = Object.values(require.cache) .filter((m) => m.children.includes(module)); ``` [`--pending-deprecation`]: cli.html#cli_pending_deprecation [`--throw-deprecation`]: cli.html#cli_throw_deprecation [`Buffer.allocUnsafeSlow(size)`]: buffer.html#buffer_class_method_buffer_allocunsafeslow_size [`Buffer.from(array)`]: buffer.html#buffer_class_method_buffer_from_array [`Buffer.from(buffer)`]: buffer.html#buffer_class_method_buffer_from_buffer [`Buffer.isBuffer()`]: buffer.html#buffer_class_method_buffer_isbuffer_obj [`Cipher`]: crypto.html#crypto_class_cipher [`Decipher`]: crypto.html#crypto_class_decipher [`EventEmitter.listenerCount(emitter, eventName)`]: events.html#events_eventemitter_listenercount_emitter_eventname [`REPLServer.clearBufferedCommand()`]: repl.html#repl_replserver_clearbufferedcommand [`ReadStream.open()`]: fs.html#fs_class_fs_readstream [`Server.getConnections()`]: net.html#net_server_getconnections_callback [`Server.listen({fd: })`]: net.html#net_server_listen_handle_backlog_callback [`SlowBuffer`]: buffer.html#buffer_class_slowbuffer [`WriteStream.open()`]: fs.html#fs_class_fs_writestream [`assert`]: assert.html [`asyncResource.runInAsyncScope()`]: async_hooks.html#async_hooks_asyncresource_runinasyncscope_fn_thisarg_args [`child_process`]: child_process.html [`clearInterval()`]: timers.html#timers_clearinterval_timeout [`clearTimeout()`]: timers.html#timers_cleartimeout_timeout [`console.error()`]: console.html#console_console_error_data_args [`console.log()`]: console.html#console_console_log_data_args [`crypto.DEFAULT_ENCODING`]: crypto.html#crypto_crypto_default_encoding [`crypto.createCipher()`]: crypto.html#crypto_crypto_createcipher_algorithm_password_options [`crypto.createCipheriv()`]: crypto.html#crypto_crypto_createcipheriv_algorithm_key_iv_options [`crypto.createDecipher()`]: crypto.html#crypto_crypto_createdecipher_algorithm_password_options [`crypto.createDecipheriv()`]: crypto.html#crypto_crypto_createdecipheriv_algorithm_key_iv_options [`crypto.fips`]: crypto.html#crypto_crypto_fips [`crypto.pbkdf2()`]: crypto.html#crypto_crypto_pbkdf2_password_salt_iterations_keylen_digest_callback [`crypto.randomBytes()`]: crypto.html#crypto_crypto_randombytes_size_callback [`crypto.scrypt()`]: crypto.html#crypto_crypto_scrypt_password_salt_keylen_options_callback [`decipher.final()`]: crypto.html#crypto_decipher_final_outputencoding [`decipher.setAuthTag()`]: crypto.html#crypto_decipher_setauthtag_buffer [`domain`]: domain.html [`ecdh.setPublicKey()`]: crypto.html#crypto_ecdh_setpublickey_publickey_encoding [`emitter.listenerCount(eventName)`]: events.html#events_emitter_listenercount_eventname [`fs.FileHandle`]: fs.html#fs_class_filehandle [`fs.access()`]: fs.html#fs_fs_access_path_mode_callback [`fs.createReadStream()`]: fs.html#fs_fs_createreadstream_path_options [`fs.createWriteStream()`]: fs.html#fs_fs_createwritestream_path_options [`fs.exists(path, callback)`]: fs.html#fs_fs_exists_path_callback [`fs.lchmod(path, mode, callback)`]: fs.html#fs_fs_lchmod_path_mode_callback [`fs.lchmodSync(path, mode)`]: fs.html#fs_fs_lchmodsync_path_mode [`fs.lchown(path, uid, gid, callback)`]: fs.html#fs_fs_lchown_path_uid_gid_callback [`fs.lchownSync(path, uid, gid)`]: fs.html#fs_fs_lchownsync_path_uid_gid [`fs.read()`]: fs.html#fs_fs_read_fd_buffer_offset_length_position_callback [`fs.readSync()`]: fs.html#fs_fs_readsync_fd_buffer_offset_length_position [`fs.stat()`]: fs.html#fs_fs_stat_path_options_callback [`http.get()`]: http.html#http_http_get_options_callback [`http.request()`]: http.html#http_http_request_options_callback [`https.get()`]: https.html#https_https_get_options_callback [`https.request()`]: https.html#https_https_request_options_callback [`module.createRequire()`]: modules.html#modules_module_createrequire_filename [`os.networkInterfaces()`]: os.html#os_os_networkinterfaces [`os.tmpdir()`]: os.html#os_os_tmpdir [`process.env`]: process.html#process_process_env [`process.mainModule`]: process.html#process_process_mainmodule [`punycode`]: punycode.html [`require.extensions`]: modules.html#modules_require_extensions [`require.main`]: modules.html#modules_accessing_the_main_module [`request.abort()`]: http.html#http_request_abort [`request.socket`]: http.html#http_request_socket [`request.connection`]: http.html#http_request_connection [`request.destroy()`]: http.html#http_request_destroy_error [`response.socket`]: http.html#http_response_socket [`response.connection`]: http.html#http_response_connection [`response.end()`]: http.html#http_response_end_data_encoding_callback [`response.finished`]: #http_response_finished [`response.writableFinished`]: #http_response_writablefinished [`response.writableEnded`]: #http_response_writableended [`script.createCachedData()`]: vm.html#vm_script_createcacheddata [`setInterval()`]: timers.html#timers_setinterval_callback_delay_args [`setTimeout()`]: timers.html#timers_settimeout_callback_delay_args [`timeout.ref()`]: timers.html#timers_timeout_ref [`timeout.refresh()`]: timers.html#timers_timeout_refresh [`timeout.unref()`]: timers.html#timers_timeout_unref [`tls.CryptoStream`]: tls.html#tls_class_cryptostream [`tls.SecureContext`]: tls.html#tls_tls_createsecurecontext_options [`tls.SecurePair`]: tls.html#tls_class_securepair [`tls.TLSSocket`]: tls.html#tls_class_tls_tlssocket [`tls.checkServerIdentity()`]: tls.html#tls_tls_checkserveridentity_hostname_cert [`tls.createSecureContext()`]: tls.html#tls_tls_createsecurecontext_options [`url.format()`]: url.html#url_url_format_urlobject [`url.parse()`]: url.html#url_url_parse_urlstring_parsequerystring_slashesdenotehost [`url.resolve()`]: url.html#url_url_resolve_from_to [`util._extend()`]: util.html#util_util_extend_target_source [`util.getSystemErrorName()`]: util.html#util_util_getsystemerrorname_err [`util.inspect()`]: util.html#util_util_inspect_object_options [`util.inspect.custom`]: util.html#util_util_inspect_custom [`util.isArray()`]: util.html#util_util_isarray_object [`util.isBoolean()`]: util.html#util_util_isboolean_object [`util.isBuffer()`]: util.html#util_util_isbuffer_object [`util.isDate()`]: util.html#util_util_isdate_object [`util.isError()`]: util.html#util_util_iserror_object [`util.isFunction()`]: util.html#util_util_isfunction_object [`util.isNull()`]: util.html#util_util_isnull_object [`util.isNullOrUndefined()`]: util.html#util_util_isnullorundefined_object [`util.isNumber()`]: util.html#util_util_isnumber_object [`util.isObject()`]: util.html#util_util_isobject_object [`util.isPrimitive()`]: util.html#util_util_isprimitive_object [`util.isRegExp()`]: util.html#util_util_isregexp_object [`util.isString()`]: util.html#util_util_isstring_object [`util.isSymbol()`]: util.html#util_util_issymbol_object [`util.isUndefined()`]: util.html#util_util_isundefined_object [`util.log()`]: util.html#util_util_log_string [`util.types`]: util.html#util_util_types [`util`]: util.html [`worker.exitedAfterDisconnect`]: cluster.html#cluster_worker_exitedafterdisconnect [`worker.terminate()`]: worker_threads.html#worker_threads_worker_terminate [`zlib.bytesWritten`]: zlib.html#zlib_zlib_byteswritten [Legacy URL API]: url.html#url_legacy_url_api [NIST SP 800-38D]: https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf [RFC 6066]: https://tools.ietf.org/html/rfc6066#section-3 [WHATWG URL API]: url.html#url_the_whatwg_url_api [alloc]: buffer.html#buffer_class_method_buffer_alloc_size_fill_encoding [alloc_unsafe_size]: buffer.html#buffer_class_method_buffer_allocunsafe_size [from_arraybuffer]: buffer.html#buffer_class_method_buffer_from_arraybuffer_byteoffset_length [from_string_encoding]: buffer.html#buffer_class_method_buffer_from_string_encoding [legacy `urlObject`]: url.html#url_legacy_urlobject