Source Code: lib/http.js
\nTo use the HTTP server and client one must require('http').
The HTTP interfaces in Node.js are designed to support many features\nof the protocol which have been traditionally difficult to use.\nIn particular, large, possibly chunk-encoded, messages. The interface is\ncareful to never buffer entire requests or responses, so the\nuser is able to stream data.
\nHTTP message headers are represented by an object like this:
\n\n{ 'content-length': '123',\n 'content-type': 'text/plain',\n 'connection': 'keep-alive',\n 'host': 'mysite.com',\n 'accept': '*/*' }\nKeys are lowercased. Values are not modified.
\nIn order to support the full spectrum of possible HTTP applications, the Node.js\nHTTP API is very low-level. It deals with stream handling and message\nparsing only. It parses a message into headers and body but it does not\nparse the actual headers or the body.
\nSee message.headers for details on how duplicate headers are handled.
The raw headers as they were received are retained in the rawHeaders\nproperty, which is an array of [key, value, key2, value2, ...]. For\nexample, the previous message header object might have a rawHeaders\nlist like the following:
[ 'ConTent-Length', '123456',\n 'content-LENGTH', '123',\n 'content-type', 'text/plain',\n 'CONNECTION', 'keep-alive',\n 'Host', 'mysite.com',\n 'accepT', '*/*' ]\nAn Agent is responsible for managing connection persistence\nand reuse for HTTP clients. It maintains a queue of pending requests\nfor a given host and port, reusing a single socket connection for each\nuntil the queue is empty, at which time the socket is either destroyed\nor put into a pool where it is kept to be used again for requests to the\nsame host and port. Whether it is destroyed or pooled depends on the\nkeepAlive option.
Pooled connections have TCP Keep-Alive enabled for them, but servers may\nstill close idle connections, in which case they will be removed from the\npool and a new connection will be made when a new HTTP request is made for\nthat host and port. Servers may also refuse to allow multiple requests\nover the same connection, in which case the connection will have to be\nremade for every request and cannot be pooled. The Agent will still make\nthe requests to that server, but each one will occur over a new connection.
When a connection is closed by the client or the server, it is removed\nfrom the pool. Any unused sockets in the pool will be unrefed so as not\nto keep the Node.js process running when there are no outstanding requests.\n(see socket.unref()).
It is good practice, to destroy() an Agent instance when it is no\nlonger in use, because unused sockets consume OS resources.
Sockets are removed from an agent when the socket emits either\na 'close' event or an 'agentRemove' event. When intending to keep one\nHTTP request open for a long time without keeping it in the agent, something\nlike the following may be done:
http.get(options, (res) => {\n // Do stuff\n}).on('socket', (socket) => {\n socket.emit('agentRemove');\n});\nAn agent may also be used for an individual request. By providing\n{agent: false} as an option to the http.get() or http.request()\nfunctions, a one-time use Agent with default options will be used\nfor the client connection.
agent:false:
http.get({\n hostname: 'localhost',\n port: 80,\n path: '/',\n agent: false // Create a new agent just for this one request\n}, (res) => {\n // Do stuff with response\n});\nProduces a socket/stream to be used for HTTP requests.
\nBy default, this function is the same as net.createConnection(). However,\ncustom agents may override this method in case greater flexibility is desired.
A socket/stream can be supplied in one of two ways: by returning the\nsocket/stream from this function, or by passing the socket/stream to callback.
This method is guaranteed to return an instance of the <net.Socket> class,\na subclass of <stream.Duplex>, unless the user specifies a socket\ntype other than <net.Socket>.
\ncallback has a signature of (err, stream).
Called when socket is detached from a request and could be persisted by the\nAgent. Default behavior is to:
socket.setKeepAlive(true, this.keepAliveMsecs);\nsocket.unref();\nreturn true;\nThis method can be overridden by a particular Agent subclass. If this\nmethod returns a falsy value, the socket will be destroyed instead of persisting\nit for use with the next request.
The socket argument can be an instance of <net.Socket>, a subclass of\n<stream.Duplex>.
Called when socket is attached to request after being persisted because of\nthe keep-alive options. Default behavior is to:
socket.ref();\nThis method can be overridden by a particular Agent subclass.
The socket argument can be an instance of <net.Socket>, a subclass of\n<stream.Duplex>.
Destroy any sockets that are currently in use by the agent.
\nIt is usually not necessary to do this. However, if using an\nagent with keepAlive enabled, then it is best to explicitly shut down\nthe agent when it is no longer needed. Otherwise,\nsockets might stay open for quite a long time before the server\nterminates them.
Get a unique name for a set of request options, to determine whether a\nconnection can be reused. For an HTTP agent, this returns\nhost:port:localAddress or host:port:localAddress:family. For an HTTPS agent,\nthe name includes the CA, cert, ciphers, and other HTTPS/TLS-specific options\nthat determine socket reusability.
An object which contains arrays of sockets currently awaiting use by\nthe agent when keepAlive is enabled. Do not modify.
Sockets in the freeSockets list will be automatically destroyed and\nremoved from the array on 'timeout'.
By default set to 256. For agents with keepAlive enabled, this\nsets the maximum number of sockets that will be left open in the free\nstate.
By default set to Infinity. Determines how many concurrent sockets the agent\ncan have open per origin. Origin is the returned value of agent.getName().
By default set to Infinity. Determines how many concurrent sockets the agent\ncan have open. Unlike maxSockets, this parameter applies across all origins.
An object which contains queues of requests that have not yet been assigned to\nsockets. Do not modify.
" }, { "textRaw": "`sockets` {Object}", "type": "Object", "name": "sockets", "meta": { "added": [ "v0.3.6" ], "changes": [ { "version": "v16.0.0", "pr-url": "https://github.com/nodejs/node/pull/36409", "description": "The property now has a `null` prototype." } ] }, "desc": "An object which contains arrays of sockets currently in use by the\nagent. Do not modify.
" } ], "signatures": [ { "params": [ { "textRaw": "`options` {Object} Set of configurable options to set on the agent. Can have the following fields:", "name": "options", "type": "Object", "desc": "Set of configurable options to set on the agent. Can have the following fields:", "options": [ { "textRaw": "`keepAlive` {boolean} Keep sockets around even when there are no outstanding requests, so they can be used for future requests without having to reestablish a TCP connection. Not to be confused with the `keep-alive` value of the `Connection` header. The `Connection: keep-alive` header is always sent when using an agent except when the `Connection` header is explicitly specified or when the `keepAlive` and `maxSockets` options are respectively set to `false` and `Infinity`, in which case `Connection: close` will be used. **Default:** `false`.", "name": "keepAlive", "type": "boolean", "default": "`false`", "desc": "Keep sockets around even when there are no outstanding requests, so they can be used for future requests without having to reestablish a TCP connection. Not to be confused with the `keep-alive` value of the `Connection` header. The `Connection: keep-alive` header is always sent when using an agent except when the `Connection` header is explicitly specified or when the `keepAlive` and `maxSockets` options are respectively set to `false` and `Infinity`, in which case `Connection: close` will be used." }, { "textRaw": "`keepAliveMsecs` {number} When using the `keepAlive` option, specifies the [initial delay](net.md#net_socket_setkeepalive_enable_initialdelay) for TCP Keep-Alive packets. Ignored when the `keepAlive` option is `false` or `undefined`. **Default:** `1000`.", "name": "keepAliveMsecs", "type": "number", "default": "`1000`", "desc": "When using the `keepAlive` option, specifies the [initial delay](net.md#net_socket_setkeepalive_enable_initialdelay) for TCP Keep-Alive packets. Ignored when the `keepAlive` option is `false` or `undefined`." }, { "textRaw": "`maxSockets` {number} Maximum number of sockets to allow per host. If the same host opens multiple concurrent connections, each request will use new socket until the `maxSockets` value is reached. If the host attempts to open more connections than `maxSockets`, the additional requests will enter into a pending request queue, and will enter active connection state when an existing connection terminates. This makes sure there are at most `maxSockets` active connections at any point in time, from a given host. **Default:** `Infinity`.", "name": "maxSockets", "type": "number", "default": "`Infinity`", "desc": "Maximum number of sockets to allow per host. If the same host opens multiple concurrent connections, each request will use new socket until the `maxSockets` value is reached. If the host attempts to open more connections than `maxSockets`, the additional requests will enter into a pending request queue, and will enter active connection state when an existing connection terminates. This makes sure there are at most `maxSockets` active connections at any point in time, from a given host." }, { "textRaw": "`maxTotalSockets` {number} Maximum number of sockets allowed for all hosts in total. Each request will use a new socket until the maximum is reached. **Default:** `Infinity`.", "name": "maxTotalSockets", "type": "number", "default": "`Infinity`", "desc": "Maximum number of sockets allowed for all hosts in total. Each request will use a new socket until the maximum is reached." }, { "textRaw": "`maxFreeSockets` {number} Maximum number of sockets to leave open in a free state. Only relevant if `keepAlive` is set to `true`. **Default:** `256`.", "name": "maxFreeSockets", "type": "number", "default": "`256`", "desc": "Maximum number of sockets to leave open in a free state. Only relevant if `keepAlive` is set to `true`." }, { "textRaw": "`scheduling` {string} Scheduling strategy to apply when picking the next free socket to use. It can be `'fifo'` or `'lifo'`. The main difference between the two scheduling strategies is that `'lifo'` selects the most recently used socket, while `'fifo'` selects the least recently used socket. In case of a low rate of request per second, the `'lifo'` scheduling will lower the risk of picking a socket that might have been closed by the server due to inactivity. In case of a high rate of request per second, the `'fifo'` scheduling will maximize the number of open sockets, while the `'lifo'` scheduling will keep it as low as possible. **Default:** `'lifo'`.", "name": "scheduling", "type": "string", "default": "`'lifo'`", "desc": "Scheduling strategy to apply when picking the next free socket to use. It can be `'fifo'` or `'lifo'`. The main difference between the two scheduling strategies is that `'lifo'` selects the most recently used socket, while `'fifo'` selects the least recently used socket. In case of a low rate of request per second, the `'lifo'` scheduling will lower the risk of picking a socket that might have been closed by the server due to inactivity. In case of a high rate of request per second, the `'fifo'` scheduling will maximize the number of open sockets, while the `'lifo'` scheduling will keep it as low as possible." }, { "textRaw": "`timeout` {number} Socket timeout in milliseconds. This will set the timeout when the socket is created.", "name": "timeout", "type": "number", "desc": "Socket timeout in milliseconds. This will set the timeout when the socket is created." } ] } ], "desc": "options in socket.connect() are also supported.
The default http.globalAgent that is used by http.request() has all\nof these values set to their respective defaults.
To configure any of them, a custom http.Agent instance must be created.
const http = require('http');\nconst keepAliveAgent = new http.Agent({ keepAlive: true });\noptions.agent = keepAliveAgent;\nhttp.request(options, onResponseCallback);\nThis object is created internally and returned from http.request(). It\nrepresents an in-progress request whose header has already been queued. The\nheader is still mutable using the setHeader(name, value),\ngetHeader(name), removeHeader(name) API. The actual header will\nbe sent along with the first data chunk or when calling request.end().
To get the response, add a listener for 'response' to the request object.\n'response' will be emitted from the request object when the response\nheaders have been received. The 'response' event is executed with one\nargument which is an instance of http.IncomingMessage.
During the 'response' event, one can add listeners to the\nresponse object; particularly to listen for the 'data' event.
If no 'response' handler is added, then the response will be\nentirely discarded. However, if a 'response' event handler is added,\nthen the data from the response object must be consumed, either by\ncalling response.read() whenever there is a 'readable' event, or\nby adding a 'data' handler, or by calling the .resume() method.\nUntil the data is consumed, the 'end' event will not fire. Also, until\nthe data is read it will consume memory that can eventually lead to a\n'process out of memory' error.
For backward compatibility, res will only emit 'error' if there is an\n'error' listener registered.
Node.js does not check whether Content-Length and the length of the\nbody which has been transmitted are equal or not.
", "events": [ { "textRaw": "Event: `'abort'`", "type": "event", "name": "abort", "meta": { "added": [ "v1.4.1" ], "changes": [] }, "params": [], "desc": "Emitted when the request has been aborted by the client. This event is only\nemitted on the first call to abort().
Emitted each time a server responds to a request with a CONNECT method. If\nthis event is not being listened for, clients receiving a CONNECT method will\nhave their connections closed.
This event is guaranteed to be passed an instance of the <net.Socket> class,\na subclass of <stream.Duplex>, unless the user specifies a socket\ntype other than <net.Socket>.
\nA client and server pair demonstrating how to listen for the 'connect' event:
const http = require('http');\nconst net = require('net');\nconst { URL } = require('url');\n\n// Create an HTTP tunneling proxy\nconst proxy = http.createServer((req, res) => {\n res.writeHead(200, { 'Content-Type': 'text/plain' });\n res.end('okay');\n});\nproxy.on('connect', (req, clientSocket, head) => {\n // Connect to an origin server\n const { port, hostname } = new URL(`http://${req.url}`);\n const serverSocket = net.connect(port || 80, hostname, () => {\n clientSocket.write('HTTP/1.1 200 Connection Established\\r\\n' +\n 'Proxy-agent: Node.js-Proxy\\r\\n' +\n '\\r\\n');\n serverSocket.write(head);\n serverSocket.pipe(clientSocket);\n clientSocket.pipe(serverSocket);\n });\n});\n\n// Now that proxy is running\nproxy.listen(1337, '127.0.0.1', () => {\n\n // Make a request to a tunneling proxy\n const options = {\n port: 1337,\n host: '127.0.0.1',\n method: 'CONNECT',\n path: 'www.google.com:80'\n };\n\n const req = http.request(options);\n req.end();\n\n req.on('connect', (res, socket, head) => {\n console.log('got connected!');\n\n // Make a request over an HTTP tunnel\n socket.write('GET / HTTP/1.1\\r\\n' +\n 'Host: www.google.com:80\\r\\n' +\n 'Connection: close\\r\\n' +\n '\\r\\n');\n socket.on('data', (chunk) => {\n console.log(chunk.toString());\n });\n socket.on('end', () => {\n proxy.close();\n });\n });\n});\nEmitted when the server sends a '100 Continue' HTTP response, usually because\nthe request contained 'Expect: 100-continue'. This is an instruction that\nthe client should send the request body.
" }, { "textRaw": "Event: `'information'`", "type": "event", "name": "information", "meta": { "added": [ "v10.0.0" ], "changes": [] }, "params": [ { "textRaw": "`info` {Object}", "name": "info", "type": "Object", "options": [ { "textRaw": "`httpVersion` {string}", "name": "httpVersion", "type": "string" }, { "textRaw": "`httpVersionMajor` {integer}", "name": "httpVersionMajor", "type": "integer" }, { "textRaw": "`httpVersionMinor` {integer}", "name": "httpVersionMinor", "type": "integer" }, { "textRaw": "`statusCode` {integer}", "name": "statusCode", "type": "integer" }, { "textRaw": "`statusMessage` {string}", "name": "statusMessage", "type": "string" }, { "textRaw": "`headers` {Object}", "name": "headers", "type": "Object" }, { "textRaw": "`rawHeaders` {string[]}", "name": "rawHeaders", "type": "string[]" } ] } ], "desc": "Emitted when the server sends a 1xx intermediate response (excluding 101\nUpgrade). The listeners of this event will receive an object containing the\nHTTP version, status code, status message, key-value headers object,\nand array with the raw header names followed by their respective values.
\nconst http = require('http');\n\nconst options = {\n host: '127.0.0.1',\n port: 8080,\n path: '/length_request'\n};\n\n// Make a request\nconst req = http.request(options);\nreq.end();\n\nreq.on('information', (info) => {\n console.log(`Got information prior to main response: ${info.statusCode}`);\n});\n101 Upgrade statuses do not fire this event due to their break from the\ntraditional HTTP request/response chain, such as web sockets, in-place TLS\nupgrades, or HTTP 2.0. To be notified of 101 Upgrade notices, listen for the\n'upgrade' event instead.
Emitted when a response is received to this request. This event is emitted only\nonce.
" }, { "textRaw": "Event: `'socket'`", "type": "event", "name": "socket", "meta": { "added": [ "v0.5.3" ], "changes": [] }, "params": [ { "textRaw": "`socket` {stream.Duplex}", "name": "socket", "type": "stream.Duplex" } ], "desc": "This event is guaranteed to be passed an instance of the <net.Socket> class,\na subclass of <stream.Duplex>, unless the user specifies a socket\ntype other than <net.Socket>.
" }, { "textRaw": "Event: `'timeout'`", "type": "event", "name": "timeout", "meta": { "added": [ "v0.7.8" ], "changes": [] }, "params": [], "desc": "Emitted when the underlying socket times out from inactivity. This only notifies\nthat the socket has been idle. The request must be aborted manually.
\nSee also: request.setTimeout().
Emitted each time a server responds to a request with an upgrade. If this\nevent is not being listened for and the response status code is 101 Switching\nProtocols, clients receiving an upgrade header will have their connections\nclosed.
\nThis event is guaranteed to be passed an instance of the <net.Socket> class,\na subclass of <stream.Duplex>, unless the user specifies a socket\ntype other than <net.Socket>.
\nA client server pair demonstrating how to listen for the 'upgrade' event.
const http = require('http');\n\n// Create an HTTP server\nconst server = http.createServer((req, res) => {\n res.writeHead(200, { 'Content-Type': 'text/plain' });\n res.end('okay');\n});\nserver.on('upgrade', (req, socket, head) => {\n socket.write('HTTP/1.1 101 Web Socket Protocol Handshake\\r\\n' +\n 'Upgrade: WebSocket\\r\\n' +\n 'Connection: Upgrade\\r\\n' +\n '\\r\\n');\n\n socket.pipe(socket); // echo back\n});\n\n// Now that server is running\nserver.listen(1337, '127.0.0.1', () => {\n\n // make a request\n const options = {\n port: 1337,\n host: '127.0.0.1',\n headers: {\n 'Connection': 'Upgrade',\n 'Upgrade': 'websocket'\n }\n };\n\n const req = http.request(options);\n req.end();\n\n req.on('upgrade', (res, socket, upgradeHead) => {\n console.log('got upgraded!');\n socket.end();\n process.exit(0);\n });\n});\nMarks the request as aborting. Calling this will cause remaining data\nin the response to be dropped and the socket to be destroyed.
" }, { "textRaw": "`request.end([data[, encoding]][, callback])`", "type": "method", "name": "end", "meta": { "added": [ "v0.1.90" ], "changes": [ { "version": "v10.0.0", "pr-url": "https://github.com/nodejs/node/pull/18780", "description": "This method now returns a reference to `ClientRequest`." } ] }, "signatures": [ { "return": { "textRaw": "Returns: {this}", "name": "return", "type": "this" }, "params": [ { "textRaw": "`data` {string|Buffer}", "name": "data", "type": "string|Buffer" }, { "textRaw": "`encoding` {string}", "name": "encoding", "type": "string" }, { "textRaw": "`callback` {Function}", "name": "callback", "type": "Function" } ] } ], "desc": "Finishes sending the request. If any parts of the body are\nunsent, it will flush them to the stream. If the request is\nchunked, this will send the terminating '0\\r\\n\\r\\n'.
If data is specified, it is equivalent to calling\nrequest.write(data, encoding) followed by request.end(callback).
If callback is specified, it will be called when the request stream\nis finished.
Destroy the request. Optionally emit an 'error' event,\nand emit a 'close' event. Calling this will cause remaining data\nin the response to be dropped and the socket to be destroyed.
See writable.destroy() for further details.
Is true after request.destroy() has been called.
See writable.destroyed for further details.
Flushes the request headers.
\nFor efficiency reasons, Node.js normally buffers the request headers until\nrequest.end() is called or the first chunk of request data is written. It\nthen tries to pack the request headers and data into a single TCP packet.
That's usually desired (it saves a TCP round-trip), but not when the first\ndata is not sent until possibly much later. request.flushHeaders() bypasses\nthe optimization and kickstarts the request.
Reads out a header on the request. The name is case-insensitive.\nThe type of the return value depends on the arguments provided to\nrequest.setHeader().
request.setHeader('content-type', 'text/html');\nrequest.setHeader('Content-Length', Buffer.byteLength(body));\nrequest.setHeader('Cookie', ['type=ninja', 'language=javascript']);\nconst contentType = request.getHeader('Content-Type');\n// 'contentType' is 'text/html'\nconst contentLength = request.getHeader('Content-Length');\n// 'contentLength' is of type number\nconst cookie = request.getHeader('Cookie');\n// 'cookie' is of type string[]\nReturns an array containing the unique names of the current outgoing raw\nheaders. Header names are returned with their exact casing being set.
\nrequest.setHeader('Foo', 'bar');\nrequest.setHeader('Set-Cookie', ['foo=bar', 'bar=baz']);\n\nconst headerNames = request.getRawHeaderNames();\n// headerNames === ['Foo', 'Set-Cookie']\nRemoves a header that's already defined into headers object.
\nrequest.removeHeader('Content-Type');\nSets a single header value for headers object. If this header already exists in\nthe to-be-sent headers, its value will be replaced. Use an array of strings\nhere to send multiple headers with the same name. Non-string values will be\nstored without modification. Therefore, request.getHeader() may return\nnon-string values. However, the non-string values will be converted to strings\nfor network transmission.
request.setHeader('Content-Type', 'application/json');\nor
\nrequest.setHeader('Cookie', ['type=ninja', 'language=javascript']);\nOnce a socket is assigned to this request and is connected\nsocket.setNoDelay() will be called.
Once a socket is assigned to this request and is connected\nsocket.setKeepAlive() will be called.
Once a socket is assigned to this request and is connected\nsocket.setTimeout() will be called.
Sends a chunk of the body. This method can be called multiple times. If no\nContent-Length is set, data will automatically be encoded in HTTP Chunked\ntransfer encoding, so that server knows when the data ends. The\nTransfer-Encoding: chunked header is added. Calling request.end()\nis necessary to finish sending the request.
The encoding argument is optional and only applies when chunk is a string.\nDefaults to 'utf8'.
The callback argument is optional and will be called when this chunk of data\nis flushed, but only if the chunk is non-empty.
Returns true if the entire data was flushed successfully to the kernel\nbuffer. Returns false if all or part of the data was queued in user memory.\n'drain' will be emitted when the buffer is free again.
When write function is called with empty string or buffer, it does\nnothing and waits for more input.
The request.aborted property will be true if the request has\nbeen aborted.
See request.socket.
The request.finished property will be true if request.end()\nhas been called. request.end() will automatically be called if the\nrequest was initiated via http.get().
Limits maximum response headers count. If set to 0, no limit will be applied.
" }, { "textRaw": "`path` {string} The request path.", "type": "string", "name": "path", "meta": { "added": [ "v0.4.0" ], "changes": [] }, "desc": "The request path." }, { "textRaw": "`method` {string} The request method.", "type": "string", "name": "method", "meta": { "added": [ "v0.1.97" ], "changes": [] }, "desc": "The request method." }, { "textRaw": "`host` {string} The request host.", "type": "string", "name": "host", "meta": { "added": [ "v14.5.0", "v12.19.0" ], "changes": [] }, "desc": "The request host." }, { "textRaw": "`protocol` {string} The request protocol.", "type": "string", "name": "protocol", "meta": { "added": [ "v14.5.0", "v12.19.0" ], "changes": [] }, "desc": "The request protocol." }, { "textRaw": "`reusedSocket` {boolean} Whether the request is send through a reused socket.", "type": "boolean", "name": "reusedSocket", "meta": { "added": [ "v13.0.0", "v12.16.0" ], "changes": [] }, "desc": "When sending request through a keep-alive enabled agent, the underlying socket\nmight be reused. But if server closes connection at unfortunate time, client\nmay run into a 'ECONNRESET' error.
\nconst http = require('http');\n\n// Server has a 5 seconds keep-alive timeout by default\nhttp\n .createServer((req, res) => {\n res.write('hello\\n');\n res.end();\n })\n .listen(3000);\n\nsetInterval(() => {\n // Adapting a keep-alive agent\n http.get('http://localhost:3000', { agent }, (res) => {\n res.on('data', (data) => {\n // Do nothing\n });\n });\n}, 5000); // Sending request on 5s interval so it's easy to hit idle timeout\nBy marking a request whether it reused socket or not, we can do\nautomatic error retry base on it.
\nconst http = require('http');\nconst agent = new http.Agent({ keepAlive: true });\n\nfunction retriableRequest() {\n const req = http\n .get('http://localhost:3000', { agent }, (res) => {\n // ...\n })\n .on('error', (err) => {\n // Check if retry is needed\n if (req.reusedSocket && err.code === 'ECONNRESET') {\n retriableRequest();\n }\n });\n}\n\nretriableRequest();\nReference to the underlying socket. Usually users will not want to access\nthis property. In particular, the socket will not emit 'readable' events\nbecause of how the protocol parser attaches to the socket.
const http = require('http');\nconst options = {\n host: 'www.google.com',\n};\nconst req = http.get(options);\nreq.end();\nreq.once('response', (res) => {\n const ip = req.socket.localAddress;\n const port = req.socket.localPort;\n console.log(`Your IP address is ${ip} and your source port is ${port}.`);\n // Consume response object\n});\nThis property is guaranteed to be an instance of the <net.Socket> class,\na subclass of <stream.Duplex>, unless the user specified a socket\ntype other than <net.Socket>.
" }, { "textRaw": "`writableEnded` {boolean}", "type": "boolean", "name": "writableEnded", "meta": { "added": [ "v12.9.0" ], "changes": [] }, "desc": "Is true after request.end() has been called. This property\ndoes not indicate whether the data has been flushed, for this use\nrequest.writableFinished instead.
Is true if all data has been flushed to the underlying system, immediately\nbefore the 'finish' event is emitted.
Emitted each time a request with an HTTP Expect: 100-continue is received.\nIf this event is not listened for, the server will automatically respond\nwith a 100 Continue as appropriate.
Handling this event involves calling response.writeContinue() if the\nclient should continue to send the request body, or generating an appropriate\nHTTP response (e.g. 400 Bad Request) if the client should not continue to send\nthe request body.
When this event is emitted and handled, the 'request' event will\nnot be emitted.
Emitted each time a request with an HTTP Expect header is received, where the\nvalue is not 100-continue. If this event is not listened for, the server will\nautomatically respond with a 417 Expectation Failed as appropriate.
When this event is emitted and handled, the 'request' event will\nnot be emitted.
If a client connection emits an 'error' event, it will be forwarded here.\nListener of this event is responsible for closing/destroying the underlying\nsocket. For example, one may wish to more gracefully close the socket with a\ncustom HTTP response instead of abruptly severing the connection.
This event is guaranteed to be passed an instance of the <net.Socket> class,\na subclass of <stream.Duplex>, unless the user specifies a socket\ntype other than <net.Socket>.
\nDefault behavior is to try close the socket with a HTTP '400 Bad Request',\nor a HTTP '431 Request Header Fields Too Large' in the case of a\nHPE_HEADER_OVERFLOW error. If the socket is not writable or has already\nwritten data it is immediately destroyed.
socket is the net.Socket object that the error originated from.
const http = require('http');\n\nconst server = http.createServer((req, res) => {\n res.end();\n});\nserver.on('clientError', (err, socket) => {\n socket.end('HTTP/1.1 400 Bad Request\\r\\n\\r\\n');\n});\nserver.listen(8000);\nWhen the 'clientError' event occurs, there is no request or response\nobject, so any HTTP response sent, including response headers and payload,\nmust be written directly to the socket object. Care must be taken to\nensure the response is a properly formatted HTTP response message.
err is an instance of Error with two extra columns:
bytesParsed: the bytes count of request packet that Node.js may have parsed\ncorrectly;rawPacket: the raw packet of current request.In some cases, the client has already received the response and/or the socket\nhas already been destroyed, like in case of ECONNRESET errors. Before\ntrying to send data to the socket, it is better to check that it is still\nwritable.
server.on('clientError', (err, socket) => {\n if (err.code === 'ECONNRESET' || !socket.writable) {\n return;\n }\n\n socket.end('HTTP/1.1 400 Bad Request\\r\\n\\r\\n');\n});\nEmitted when the server closes.
" }, { "textRaw": "Event: `'connect'`", "type": "event", "name": "connect", "meta": { "added": [ "v0.7.0" ], "changes": [] }, "params": [ { "textRaw": "`request` {http.IncomingMessage} Arguments for the HTTP request, as it is in the [`'request'`][] event", "name": "request", "type": "http.IncomingMessage", "desc": "Arguments for the HTTP request, as it is in the [`'request'`][] event" }, { "textRaw": "`socket` {stream.Duplex} Network socket between the server and client", "name": "socket", "type": "stream.Duplex", "desc": "Network socket between the server and client" }, { "textRaw": "`head` {Buffer} The first packet of the tunneling stream (may be empty)", "name": "head", "type": "Buffer", "desc": "The first packet of the tunneling stream (may be empty)" } ], "desc": "Emitted each time a client requests an HTTP CONNECT method. If this event is\nnot listened for, then clients requesting a CONNECT method will have their\nconnections closed.
This event is guaranteed to be passed an instance of the <net.Socket> class,\na subclass of <stream.Duplex>, unless the user specifies a socket\ntype other than <net.Socket>.
\nAfter this event is emitted, the request's socket will not have a 'data'\nevent listener, meaning it will need to be bound in order to handle data\nsent to the server on that socket.
This event is emitted when a new TCP stream is established. socket is\ntypically an object of type net.Socket. Usually users will not want to\naccess this event. In particular, the socket will not emit 'readable' events\nbecause of how the protocol parser attaches to the socket. The socket can\nalso be accessed at request.socket.
This event can also be explicitly emitted by users to inject connections\ninto the HTTP server. In that case, any Duplex stream can be passed.
If socket.setTimeout() is called here, the timeout will be replaced with\nserver.keepAliveTimeout when the socket has served a request (if\nserver.keepAliveTimeout is non-zero).
This event is guaranteed to be passed an instance of the <net.Socket> class,\na subclass of <stream.Duplex>, unless the user specifies a socket\ntype other than <net.Socket>.
" }, { "textRaw": "Event: `'request'`", "type": "event", "name": "request", "meta": { "added": [ "v0.1.0" ], "changes": [] }, "params": [ { "textRaw": "`request` {http.IncomingMessage}", "name": "request", "type": "http.IncomingMessage" }, { "textRaw": "`response` {http.ServerResponse}", "name": "response", "type": "http.ServerResponse" } ], "desc": "Emitted each time there is a request. There may be multiple requests\nper connection (in the case of HTTP Keep-Alive connections).
" }, { "textRaw": "Event: `'upgrade'`", "type": "event", "name": "upgrade", "meta": { "added": [ "v0.1.94" ], "changes": [ { "version": "v10.0.0", "pr-url": "https://github.com/nodejs/node/pull/19981", "description": "Not listening to this event no longer causes the socket to be destroyed if a client sends an Upgrade header." } ] }, "params": [ { "textRaw": "`request` {http.IncomingMessage} Arguments for the HTTP request, as it is in the [`'request'`][] event", "name": "request", "type": "http.IncomingMessage", "desc": "Arguments for the HTTP request, as it is in the [`'request'`][] event" }, { "textRaw": "`socket` {stream.Duplex} Network socket between the server and client", "name": "socket", "type": "stream.Duplex", "desc": "Network socket between the server and client" }, { "textRaw": "`head` {Buffer} The first packet of the upgraded stream (may be empty)", "name": "head", "type": "Buffer", "desc": "The first packet of the upgraded stream (may be empty)" } ], "desc": "Emitted each time a client requests an HTTP upgrade. Listening to this event\nis optional and clients cannot insist on a protocol change.
\nAfter this event is emitted, the request's socket will not have a 'data'\nevent listener, meaning it will need to be bound in order to handle data\nsent to the server on that socket.
This event is guaranteed to be passed an instance of the <net.Socket> class,\na subclass of <stream.Duplex>, unless the user specifies a socket\ntype other than <net.Socket>.
" } ], "methods": [ { "textRaw": "`server.close([callback])`", "type": "method", "name": "close", "meta": { "added": [ "v0.1.90" ], "changes": [] }, "signatures": [ { "params": [ { "textRaw": "`callback` {Function}", "name": "callback", "type": "Function" } ] } ], "desc": "Stops the server from accepting new connections. See net.Server.close().
Starts the HTTP server listening for connections.\nThis method is identical to server.listen() from net.Server.
Sets the timeout value for sockets, and emits a 'timeout' event on\nthe Server object, passing the socket as an argument, if a timeout\noccurs.
If there is a 'timeout' event listener on the Server object, then it\nwill be called with the timed-out socket as an argument.
By default, the Server does not timeout sockets. However, if a callback\nis assigned to the Server's 'timeout' event, timeouts must be handled\nexplicitly.
Limit the amount of time the parser will wait to receive the complete HTTP\nheaders.
\nIn case of inactivity, the rules defined in server.timeout apply. However,\nthat inactivity based timeout would still allow the connection to be kept open\nif the headers are being sent very slowly (by default, up to a byte per 2\nminutes). In order to prevent this, whenever header data arrives an additional\ncheck is made that more than server.headersTimeout milliseconds has not\npassed since the connection was established. If the check fails, a 'timeout'\nevent is emitted on the server object, and (by default) the socket is destroyed.\nSee server.timeout for more information on how timeout behavior can be\ncustomized.
Limits maximum incoming headers count. If set to 0, no limit will be applied.
" }, { "textRaw": "`requestTimeout` {number} **Default:** `0`", "type": "number", "name": "requestTimeout", "meta": { "added": [ "v14.11.0" ], "changes": [] }, "default": "`0`", "desc": "Sets the timeout value in milliseconds for receiving the entire request from\nthe client.
\nIf the timeout expires, the server responds with status 408 without\nforwarding the request to the request listener and then closes the connection.
\nIt must be set to a non-zero value (e.g. 120 seconds) to protect against\npotential Denial-of-Service attacks in case the server is deployed without a\nreverse proxy in front.
" }, { "textRaw": "`timeout` {number} Timeout in milliseconds. **Default:** 0 (no timeout)", "type": "number", "name": "timeout", "meta": { "added": [ "v0.9.12" ], "changes": [ { "version": "v13.0.0", "pr-url": "https://github.com/nodejs/node/pull/27558", "description": "The default timeout changed from 120s to 0 (no timeout)." } ] }, "default": "0 (no timeout)", "desc": "The number of milliseconds of inactivity before a socket is presumed\nto have timed out.
\nA value of 0 will disable the timeout behavior on incoming connections.
The socket timeout logic is set up on connection, so changing this\nvalue only affects new connections to the server, not any existing connections.
", "shortDesc": "Timeout in milliseconds." }, { "textRaw": "`keepAliveTimeout` {number} Timeout in milliseconds. **Default:** `5000` (5 seconds).", "type": "number", "name": "keepAliveTimeout", "meta": { "added": [ "v8.0.0" ], "changes": [] }, "default": "`5000` (5 seconds)", "desc": "The number of milliseconds of inactivity a server needs to wait for additional\nincoming data, after it has finished writing the last response, before a socket\nwill be destroyed. If the server receives new data before the keep-alive\ntimeout has fired, it will reset the regular inactivity timeout, i.e.,\nserver.timeout.
A value of 0 will disable the keep-alive timeout behavior on incoming\nconnections.\nA value of 0 makes the http server behave similarly to Node.js versions prior\nto 8.0.0, which did not have a keep-alive timeout.
The socket timeout logic is set up on connection, so changing this value only\naffects new connections to the server, not any existing connections.
", "shortDesc": "Timeout in milliseconds." } ] }, { "textRaw": "Class: `http.ServerResponse`", "type": "class", "name": "http.ServerResponse", "meta": { "added": [ "v0.1.17" ], "changes": [] }, "desc": "This object is created internally by an HTTP server, not by the user. It is\npassed as the second parameter to the 'request' event.
Indicates that the response is completed, or its underlying connection was\nterminated prematurely (before the response completion).
" }, { "textRaw": "Event: `'finish'`", "type": "event", "name": "finish", "meta": { "added": [ "v0.3.6" ], "changes": [] }, "params": [], "desc": "Emitted when the response has been sent. More specifically, this event is\nemitted when the last segment of the response headers and body have been\nhanded off to the operating system for transmission over the network. It\ndoes not imply that the client has received anything yet.
" } ], "methods": [ { "textRaw": "`response.addTrailers(headers)`", "type": "method", "name": "addTrailers", "meta": { "added": [ "v0.3.0" ], "changes": [] }, "signatures": [ { "params": [ { "textRaw": "`headers` {Object}", "name": "headers", "type": "Object" } ] } ], "desc": "This method adds HTTP trailing headers (a header but at the end of the\nmessage) to the response.
\nTrailers will only be emitted if chunked encoding is used for the\nresponse; if it is not (e.g. if the request was HTTP/1.0), they will\nbe silently discarded.
\nHTTP requires the Trailer header to be sent in order to\nemit trailers, with a list of the header fields in its value. E.g.,
response.writeHead(200, { 'Content-Type': 'text/plain',\n 'Trailer': 'Content-MD5' });\nresponse.write(fileData);\nresponse.addTrailers({ 'Content-MD5': '7895bf4b8828b55ceaf47747b4bca667' });\nresponse.end();\nAttempting to set a header field name or value that contains invalid characters\nwill result in a TypeError being thrown.
See writable.cork().
This method signals to the server that all of the response headers and body\nhave been sent; that server should consider this message complete.\nThe method, response.end(), MUST be called on each response.
If data is specified, it is similar in effect to calling\nresponse.write(data, encoding) followed by response.end(callback).
If callback is specified, it will be called when the response stream\nis finished.
Flushes the response headers. See also: request.flushHeaders().
Reads out a header that's already been queued but not sent to the client.\nThe name is case-insensitive. The type of the return value depends\non the arguments provided to response.setHeader().
response.setHeader('Content-Type', 'text/html');\nresponse.setHeader('Content-Length', Buffer.byteLength(body));\nresponse.setHeader('Set-Cookie', ['type=ninja', 'language=javascript']);\nconst contentType = response.getHeader('content-type');\n// contentType is 'text/html'\nconst contentLength = response.getHeader('Content-Length');\n// contentLength is of type number\nconst setCookie = response.getHeader('set-cookie');\n// setCookie is of type string[]\nReturns an array containing the unique names of the current outgoing headers.\nAll header names are lowercase.
\nresponse.setHeader('Foo', 'bar');\nresponse.setHeader('Set-Cookie', ['foo=bar', 'bar=baz']);\n\nconst headerNames = response.getHeaderNames();\n// headerNames === ['foo', 'set-cookie']\nReturns a shallow copy of the current outgoing headers. Since a shallow copy\nis used, array values may be mutated without additional calls to various\nheader-related http module methods. The keys of the returned object are the\nheader names and the values are the respective header values. All header names\nare lowercase.
\nThe object returned by the response.getHeaders() method does not\nprototypically inherit from the JavaScript Object. This means that typical\nObject methods such as obj.toString(), obj.hasOwnProperty(), and others\nare not defined and will not work.
response.setHeader('Foo', 'bar');\nresponse.setHeader('Set-Cookie', ['foo=bar', 'bar=baz']);\n\nconst headers = response.getHeaders();\n// headers === { foo: 'bar', 'set-cookie': ['foo=bar', 'bar=baz'] }\nReturns true if the header identified by name is currently set in the\noutgoing headers. The header name matching is case-insensitive.
const hasContentType = response.hasHeader('content-type');\nRemoves a header that's queued for implicit sending.
\nresponse.removeHeader('Content-Encoding');\nReturns the response object.
\nSets a single header value for implicit headers. If this header already exists\nin the to-be-sent headers, its value will be replaced. Use an array of strings\nhere to send multiple headers with the same name. Non-string values will be\nstored without modification. Therefore, response.getHeader() may return\nnon-string values. However, the non-string values will be converted to strings\nfor network transmission. The same response object is returned to the caller,\nto enable call chaining.
response.setHeader('Content-Type', 'text/html');\nor
\nresponse.setHeader('Set-Cookie', ['type=ninja', 'language=javascript']);\nAttempting to set a header field name or value that contains invalid characters\nwill result in a TypeError being thrown.
When headers have been set with response.setHeader(), they will be merged\nwith any headers passed to response.writeHead(), with the headers passed\nto response.writeHead() given precedence.
// Returns content-type = text/plain\nconst server = http.createServer((req, res) => {\n res.setHeader('Content-Type', 'text/html');\n res.setHeader('X-Foo', 'bar');\n res.writeHead(200, { 'Content-Type': 'text/plain' });\n res.end('ok');\n});\nIf response.writeHead() method is called and this method has not been\ncalled, it will directly write the supplied header values onto the network\nchannel without caching internally, and the response.getHeader() on the\nheader will not yield the expected result. If progressive population of headers\nis desired with potential future retrieval and modification, use\nresponse.setHeader() instead of response.writeHead().
Sets the Socket's timeout value to msecs. If a callback is\nprovided, then it is added as a listener on the 'timeout' event on\nthe response object.
If no 'timeout' listener is added to the request, the response, or\nthe server, then sockets are destroyed when they time out. If a handler is\nassigned to the request, the response, or the server's 'timeout' events,\ntimed out sockets must be handled explicitly.
See writable.uncork().
If this method is called and response.writeHead() has not been called,\nit will switch to implicit header mode and flush the implicit headers.
This sends a chunk of the response body. This method may\nbe called multiple times to provide successive parts of the body.
\nIn the http module, the response body is omitted when the\nrequest is a HEAD request. Similarly, the 204 and 304 responses\nmust not include a message body.
chunk can be a string or a buffer. If chunk is a string,\nthe second parameter specifies how to encode it into a byte stream.\ncallback will be called when this chunk of data is flushed.
This is the raw HTTP body and has nothing to do with higher-level multi-part\nbody encodings that may be used.
\nThe first time response.write() is called, it will send the buffered\nheader information and the first chunk of the body to the client. The second\ntime response.write() is called, Node.js assumes data will be streamed,\nand sends the new data separately. That is, the response is buffered up to the\nfirst chunk of the body.
Returns true if the entire data was flushed successfully to the kernel\nbuffer. Returns false if all or part of the data was queued in user memory.\n'drain' will be emitted when the buffer is free again.
Sends a HTTP/1.1 100 Continue message to the client, indicating that\nthe request body should be sent. See the 'checkContinue' event on\nServer.
Sends a response header to the request. The status code is a 3-digit HTTP\nstatus code, like 404. The last argument, headers, are the response headers.\nOptionally one can give a human-readable statusMessage as the second\nargument.
headers may be an Array where the keys and values are in the same list.\nIt is not a list of tuples. So, the even-numbered offsets are key values,\nand the odd-numbered offsets are the associated values. The array is in the same\nformat as request.rawHeaders.
Returns a reference to the ServerResponse, so that calls can be chained.
const body = 'hello world';\nresponse\n .writeHead(200, {\n 'Content-Length': Buffer.byteLength(body),\n 'Content-Type': 'text/plain'\n })\n .end(body);\nThis method must only be called once on a message and it must\nbe called before response.end() is called.
If response.write() or response.end() are called before calling\nthis, the implicit/mutable headers will be calculated and call this function.
When headers have been set with response.setHeader(), they will be merged\nwith any headers passed to response.writeHead(), with the headers passed\nto response.writeHead() given precedence.
If this method is called and response.setHeader() has not been called,\nit will directly write the supplied header values onto the network channel\nwithout caching internally, and the response.getHeader() on the header\nwill not yield the expected result. If progressive population of headers is\ndesired with potential future retrieval and modification, use\nresponse.setHeader() instead.
// Returns content-type = text/plain\nconst server = http.createServer((req, res) => {\n res.setHeader('Content-Type', 'text/html');\n res.setHeader('X-Foo', 'bar');\n res.writeHead(200, { 'Content-Type': 'text/plain' });\n res.end('ok');\n});\nContent-Length is given in bytes, not characters. Use\nBuffer.byteLength() to determine the length of the body in bytes. Node.js\ndoes not check whether Content-Length and the length of the body which has\nbeen transmitted are equal or not.
Attempting to set a header field name or value that contains invalid characters\nwill result in a TypeError being thrown.
Sends a HTTP/1.1 102 Processing message to the client, indicating that\nthe request body should be sent.
" } ], "properties": [ { "textRaw": "`connection` {stream.Duplex}", "type": "stream.Duplex", "name": "connection", "meta": { "added": [ "v0.3.0" ], "deprecated": [ "v13.0.0" ], "changes": [] }, "stability": 0, "stabilityText": "Deprecated. Use [`response.socket`][].", "desc": "See response.socket.
The response.finished property will be true if response.end()\nhas been called.
Boolean (read-only). True if headers were sent, false otherwise.
" }, { "textRaw": "`req` {http.IncomingMessage}", "type": "http.IncomingMessage", "name": "req", "meta": { "added": [ "v15.7.0" ], "changes": [] }, "desc": "A reference to the original HTTP request object.
When true, the Date header will be automatically generated and sent in\nthe response if it is not already present in the headers. Defaults to true.
\nThis should only be disabled for testing; HTTP requires the Date header\nin responses.
" }, { "textRaw": "`socket` {stream.Duplex}", "type": "stream.Duplex", "name": "socket", "meta": { "added": [ "v0.3.0" ], "changes": [] }, "desc": "Reference to the underlying socket. Usually users will not want to access\nthis property. In particular, the socket will not emit 'readable' events\nbecause of how the protocol parser attaches to the socket. After\nresponse.end(), the property is nulled.
const http = require('http');\nconst server = http.createServer((req, res) => {\n const ip = res.socket.remoteAddress;\n const port = res.socket.remotePort;\n res.end(`Your IP address is ${ip} and your source port is ${port}.`);\n}).listen(3000);\nThis property is guaranteed to be an instance of the <net.Socket> class,\na subclass of <stream.Duplex>, unless the user specified a socket\ntype other than <net.Socket>.
" }, { "textRaw": "`statusCode` {number} **Default:** `200`", "type": "number", "name": "statusCode", "meta": { "added": [ "v0.4.0" ], "changes": [] }, "default": "`200`", "desc": "When using implicit headers (not calling response.writeHead() explicitly),\nthis property controls the status code that will be sent to the client when\nthe headers get flushed.
response.statusCode = 404;\nAfter response header was sent to the client, this property indicates the\nstatus code which was sent out.
" }, { "textRaw": "`statusMessage` {string}", "type": "string", "name": "statusMessage", "meta": { "added": [ "v0.11.8" ], "changes": [] }, "desc": "When using implicit headers (not calling response.writeHead() explicitly),\nthis property controls the status message that will be sent to the client when\nthe headers get flushed. If this is left as undefined then the standard\nmessage for the status code will be used.
response.statusMessage = 'Not found';\nAfter response header was sent to the client, this property indicates the\nstatus message which was sent out.
" }, { "textRaw": "`writableEnded` {boolean}", "type": "boolean", "name": "writableEnded", "meta": { "added": [ "v12.9.0" ], "changes": [] }, "desc": "Is true after response.end() has been called. This property\ndoes not indicate whether the data has been flushed, for this use\nresponse.writableFinished instead.
Is true if all data has been flushed to the underlying system, immediately\nbefore the 'finish' event is emitted.
An IncomingMessage object is created by http.Server or\nhttp.ClientRequest and passed as the first argument to the 'request'\nand 'response' event respectively. It may be used to access response\nstatus, headers and data.
Different from its socket value which is a subclass of <stream.Duplex>, the\nIncomingMessage itself extends <stream.Readable> and is created separately to\nparse and emit the incoming HTTP headers and payload, as the underlying socket\nmay be reused multiple times in case of keep-alive.
Emitted when the request has been aborted.
" }, { "textRaw": "Event: `'close'`", "type": "event", "name": "close", "meta": { "added": [ "v0.4.2" ], "changes": [] }, "params": [], "desc": "Indicates that the underlying connection was closed.
" } ], "properties": [ { "textRaw": "`aborted` {boolean}", "type": "boolean", "name": "aborted", "meta": { "added": [ "v10.1.0" ], "changes": [] }, "desc": "The message.aborted property will be true if the request has\nbeen aborted.
The message.complete property will be true if a complete HTTP message has\nbeen received and successfully parsed.
This property is particularly useful as a means of determining if a client or\nserver fully transmitted a message before a connection was terminated:
\nconst req = http.request({\n host: '127.0.0.1',\n port: 8080,\n method: 'POST'\n}, (res) => {\n res.resume();\n res.on('end', () => {\n if (!res.complete)\n console.error(\n 'The connection was terminated while the message was still being sent');\n });\n});\nAlias for message.socket.
The request/response headers object.
\nKey-value pairs of header names and values. Header names are lower-cased.
\n// Prints something like:\n//\n// { 'user-agent': 'curl/7.22.0',\n// host: '127.0.0.1:8000',\n// accept: '*/*' }\nconsole.log(request.headers);\nDuplicates in raw headers are handled in the following ways, depending on the\nheader name:
\nage, authorization, content-length, content-type,\netag, expires, from, host, if-modified-since, if-unmodified-since,\nlast-modified, location, max-forwards, proxy-authorization, referer,\nretry-after, server, or user-agent are discarded.set-cookie is always an array. Duplicates are added to the array.cookie headers, the values are joined together with '; '.In case of server request, the HTTP version sent by the client. In the case of\nclient response, the HTTP version of the connected-to server.\nProbably either '1.1' or '1.0'.
Also message.httpVersionMajor is the first integer and\nmessage.httpVersionMinor is the second.
Only valid for request obtained from http.Server.
The request method as a string. Read only. Examples: 'GET', 'DELETE'.
The raw request/response headers list exactly as they were received.
\nThe keys and values are in the same list. It is not a\nlist of tuples. So, the even-numbered offsets are key values, and the\nodd-numbered offsets are the associated values.
\nHeader names are not lowercased, and duplicates are not merged.
\n// Prints something like:\n//\n// [ 'user-agent',\n// 'this is invalid because there can be only one',\n// 'User-Agent',\n// 'curl/7.22.0',\n// 'Host',\n// '127.0.0.1:8000',\n// 'ACCEPT',\n// '*/*' ]\nconsole.log(request.rawHeaders);\nThe raw request/response trailer keys and values exactly as they were\nreceived. Only populated at the 'end' event.
The net.Socket object associated with the connection.
With HTTPS support, use request.socket.getPeerCertificate() to obtain the\nclient's authentication details.
This property is guaranteed to be an instance of the <net.Socket> class,\na subclass of <stream.Duplex>, unless the user specified a socket\ntype other than <net.Socket>.
" }, { "textRaw": "`statusCode` {number}", "type": "number", "name": "statusCode", "meta": { "added": [ "v0.1.1" ], "changes": [] }, "desc": "Only valid for response obtained from http.ClientRequest.
The 3-digit HTTP response status code. E.G. 404.
Only valid for response obtained from http.ClientRequest.
The HTTP response status message (reason phrase). E.G. OK or Internal Server Error.
The request/response trailers object. Only populated at the 'end' event.
Only valid for request obtained from http.Server.
Request URL string. This contains only the URL that is present in the actual\nHTTP request. Take the following request:
\nGET /status?name=ryan HTTP/1.1\nAccept: text/plain\nTo parse the URL into its parts:
\nnew URL(request.url, `http://${request.headers.host}`);\nWhen request.url is '/status?name=ryan' and\nrequest.headers.host is 'localhost:3000':
$ node\n> new URL(request.url, `http://${request.headers.host}`)\nURL {\n href: 'http://localhost:3000/status?name=ryan',\n origin: 'http://localhost:3000',\n protocol: 'http:',\n username: '',\n password: '',\n host: 'localhost:3000',\n hostname: 'localhost',\n port: '3000',\n pathname: '/status',\n search: '?name=ryan',\n searchParams: URLSearchParams { 'name' => 'ryan' },\n hash: ''\n}\nCalls destroy() on the socket that received the IncomingMessage. If error\nis provided, an 'error' event is emitted on the socket and error is passed\nas an argument to any listeners on the event.
Calls message.socket.setTimeout(msecs, callback).
This class serves as the parent class of http.ClientRequest\nand http.ServerResponse. It is an abstract of outgoing message from\nthe perspective of the participants of HTTP transaction.
Emitted when the buffer of the message is free again.
" }, { "textRaw": "Event: `finish`", "type": "event", "name": "finish`", "meta": { "added": [ "v0.1.17" ], "changes": [] }, "params": [], "desc": "Emitted when the transmission is finished successfully.
" }, { "textRaw": "Event: `prefinish`", "type": "event", "name": "prefinish`", "meta": { "added": [ "v0.11.6" ], "changes": [] }, "params": [], "desc": "Emitted when outgoingMessage.end was called.\nWhen the event is emitted, all data has been processed but not necessarily\ncompletely flushed.
Adds HTTP trailers (headers but at the end of the message) to the message.
\nTrailers are only be emitted if the message is chunked encoded. If not,\nthe trailer will be silently discarded.
\nHTTP requires the Trailer header to be sent to emit trailers,\nwith a list of header fields in its value, e.g.
message.writeHead(200, { 'Content-Type': 'text/plain',\n 'Trailer': 'Content-MD5' });\nmessage.write(fileData);\nmessage.addTrailers({ 'Content-MD5': '7895bf4b8828b55ceaf47747b4bca667' });\nmessage.end();\nAttempting to set a header field name or value that contains invalid characters\nwill result in a TypeError being thrown.
See writable.cork().
Destroys the message. Once a socket is associated with the message\nand is connected, that socket will be destroyed as well.
" }, { "textRaw": "`outgoingMessage.end(chunk[, encoding][, callback])`", "type": "method", "name": "end", "meta": { "added": [ "v0.1.90" ], "changes": [ { "version": "v0.11.6", "description": "add `callback` argument." } ] }, "signatures": [ { "return": { "textRaw": "Returns: {this}", "name": "return", "type": "this" }, "params": [ { "textRaw": "`chunk` {string | Buffer}", "name": "chunk", "type": "string | Buffer" }, { "textRaw": "`encoding` {string} Optional, **Default**: `utf8`", "name": "encoding", "type": "string", "desc": "Optional, **Default**: `utf8`" }, { "textRaw": "`callback` {Function} Optional", "name": "callback", "type": "Function", "desc": "Optional" } ] } ], "desc": "Finishes the outgoing message. If any parts of the body are unsent, it will\nflush them to the underlying system. If the message is chunked, it will\nsend the terminating chunk 0\\r\\n\\r\\n, and send the trailer (if any).
If chunk is specified, it is equivalent to call\noutgoingMessage.write(chunk, encoding), followed by\noutgoingMessage.end(callback).
If callback is provided, it will be called when the message is finished.\n(equivalent to the callback to event finish)
Compulsorily flushes the message headers
\nFor efficiency reason, Node.js normally buffers the message headers\nuntil outgoingMessage.end() is called or the first chunk of message data\nis written. It then tries to pack the headers and data into a single TCP\npacket.
It is usually desired (it saves a TCP round-trip), but not when the first\ndata is not sent until possibly much later. outgoingMessage.flushHeaders()\nbypasses the optimization and kickstarts the request.
Gets the value of HTTP header with the given name. If such a name doesn't\nexist in message, it will be undefined.
Returns an array of names of headers of the outgoing outgoingMessage. All\nnames are lowercase.
" }, { "textRaw": "`outgoingMessage.getHeaders()`", "type": "method", "name": "getHeaders", "meta": { "added": [ "v8.0.0" ], "changes": [] }, "signatures": [ { "return": { "textRaw": "Returns: {Object}", "name": "return", "type": "Object" }, "params": [] } ], "desc": "Returns a shallow copy of the current outgoing headers. Since a shallow\ncopy is used, array values may be mutated without additional calls to\nvarious header-related HTTP module methods. The keys of the returned\nobject are the header names and the values are the respective header\nvalues. All header names are lowercase.
\nThe object returned by the outgoingMessage.getHeaders() method does\nnot prototypically inherit from the JavaScript Object. This means that\ntypical Object methods such as obj.toString(), obj.hasOwnProperty(),\nand others are not defined and will not work.
outgoingMessage.setHeader('Foo', 'bar');\noutgoingMessage.setHeader('Set-Cookie', ['foo=bar', 'bar=baz']);\n\nconst headers = outgoingMessage.getHeaders();\n// headers === { foo: 'bar', 'set-cookie': ['foo=bar', 'bar=baz'] }\nReturns true if the header identified by name is currently set in the\noutgoing headers. The header name is case-insensitive.
const hasContentType = outgoingMessage.hasHeader('content-type');\nOverrides the pipe method of legacy Stream which is the parent class of\nhttp.outgoingMessage.
Since OutgoingMessage should be a write-only stream,\ncall this function will throw an Error. Thus, it disabled the pipe method\nit inherits from Stream.
The User should not call this function directly.
" }, { "textRaw": "`outgoingMessage.removeHeader()`", "type": "method", "name": "removeHeader", "meta": { "added": [ "v0.4.0" ], "changes": [] }, "signatures": [ { "params": [] } ], "desc": "Removes a header that is queued for implicit sending.
\noutgoingMessage.removeHeader('Content-Encoding');\nSets a single header value for the header object.
" }, { "textRaw": "`outgoingMessage.setTimeout(msesc[, callback])`", "type": "method", "name": "setTimeout", "meta": { "added": [ "v0.9.12" ], "changes": [] }, "signatures": [ { "params": [ { "textRaw": "`msesc` {number}", "name": "msesc", "type": "number" }, { "textRaw": "`callback` {Function} Optional function to be called when a timeout", "name": "callback", "type": "Function", "desc": "Optional function to be called when a timeout" } ] } ], "desc": "occurs, Same as binding to the timeout event.
Once a socket is associated with the message and is connected,\nsocket.setTimeout() will be called with msecs as the first parameter.
If this method is called and the header is not sent, it will call\nthis._implicitHeader to flush implicit header.\nIf the message should not have a body (indicated by this._hasBody),\nthe call is ignored and chunk will not be sent. It could be useful\nwhen handling a particular message which must not include a body.\ne.g. response to HEAD request, 204 and 304 response.
chunk can be a string or a buffer. When chunk is a string, the\nencoding parameter specifies how to encode chunk into a byte stream.\ncallback will be called when the chunk is flushed.
If the message is transferred in chucked encoding\n(indicated by this.chunkedEncoding), chunk will be flushed as\none chunk among a stream of chunks. Otherwise, it will be flushed as the\nbody of message.
This method handles the raw body of the HTTP message and has nothing to do\nwith higher-level multi-part body encodings that may be used.
\nIf it is the first call to this method of a message, it will send the\nbuffered header first, then flush the chunk as described above.
The second and successive calls to this method will assume the data\nwill be streamed and send the new data separately. It means that the response\nis buffered up to the first chunk of the body.
\nReturns true if the entire data was flushed successfully to the kernel\nbuffer. Returns false if all or part of the data was queued in the user\nmemory. Event drain will be emitted when the buffer is free again.
Aliases of outgoingMessage.socket
Read-only. true if the headers were sent, otherwise false.
Reference to the underlying socket. Usually, users will not want to access\nthis property.
\nAfter calling outgoingMessage.end(), this property will be nulled.
This outgoingMessage.writableCorked will return the time how many\noutgoingMessage.cork() have been called.
Readonly, true if outgoingMessage.end() has been called. Noted that\nthis property does not reflect whether the data has been flush. For that\npurpose, use message.writableFinished instead.
Readonly. true if all data has been flushed to the underlying system.
This outgoingMessage.writableHighWaterMark will be the highWaterMark of\nunderlying socket if socket exists. Else, it would be the default\nhighWaterMark.
highWaterMark is the maximum amount of data that can be potentially\nbuffered by the socket.
Readonly, This outgoingMessage.writableLength contains the number of\nbytes (or objects) in the buffer ready to send.
Readonly, always returns false.
A list of the HTTP methods that are supported by the parser.
" }, { "textRaw": "`STATUS_CODES` {Object}", "type": "Object", "name": "STATUS_CODES", "meta": { "added": [ "v0.1.22" ], "changes": [] }, "desc": "A collection of all the standard HTTP response status codes, and the\nshort description of each. For example, http.STATUS_CODES[404] === 'Not Found'.
Global instance of Agent which is used as the default for all HTTP client\nrequests.
Read-only property specifying the maximum allowed size of HTTP headers in bytes.\nDefaults to 8 KB. Configurable using the --max-http-header-size CLI\noption.
This can be overridden for servers and client requests by passing the\nmaxHeaderSize option.
Returns a new instance of http.Server.
The requestListener is a function which is automatically\nadded to the 'request' event.
Since most requests are GET requests without bodies, Node.js provides this\nconvenience method. The only difference between this method and\nhttp.request() is that it sets the method to GET and calls req.end()\nautomatically. The callback must take care to consume the response\ndata for reasons stated in http.ClientRequest section.
The callback is invoked with a single argument that is an instance of\nhttp.IncomingMessage.
JSON fetching example:
\nhttp.get('http://localhost:8000/', (res) => {\n const { statusCode } = res;\n const contentType = res.headers['content-type'];\n\n let error;\n // Any 2xx status code signals a successful response but\n // here we're only checking for 200.\n if (statusCode !== 200) {\n error = new Error('Request Failed.\\n' +\n `Status Code: ${statusCode}`);\n } else if (!/^application\\/json/.test(contentType)) {\n error = new Error('Invalid content-type.\\n' +\n `Expected application/json but received ${contentType}`);\n }\n if (error) {\n console.error(error.message);\n // Consume response data to free up memory\n res.resume();\n return;\n }\n\n res.setEncoding('utf8');\n let rawData = '';\n res.on('data', (chunk) => { rawData += chunk; });\n res.on('end', () => {\n try {\n const parsedData = JSON.parse(rawData);\n console.log(parsedData);\n } catch (e) {\n console.error(e.message);\n }\n });\n}).on('error', (e) => {\n console.error(`Got error: ${e.message}`);\n});\n\n// Create a local server to receive data from\nconst server = http.createServer((req, res) => {\n res.writeHead(200, { 'Content-Type': 'application/json' });\n res.end(JSON.stringify({\n data: 'Hello World!'\n }));\n});\n\nserver.listen(8000);\nSince most requests are GET requests without bodies, Node.js provides this\nconvenience method. The only difference between this method and\nhttp.request() is that it sets the method to GET and calls req.end()\nautomatically. The callback must take care to consume the response\ndata for reasons stated in http.ClientRequest section.
The callback is invoked with a single argument that is an instance of\nhttp.IncomingMessage.
JSON fetching example:
\nhttp.get('http://localhost:8000/', (res) => {\n const { statusCode } = res;\n const contentType = res.headers['content-type'];\n\n let error;\n // Any 2xx status code signals a successful response but\n // here we're only checking for 200.\n if (statusCode !== 200) {\n error = new Error('Request Failed.\\n' +\n `Status Code: ${statusCode}`);\n } else if (!/^application\\/json/.test(contentType)) {\n error = new Error('Invalid content-type.\\n' +\n `Expected application/json but received ${contentType}`);\n }\n if (error) {\n console.error(error.message);\n // Consume response data to free up memory\n res.resume();\n return;\n }\n\n res.setEncoding('utf8');\n let rawData = '';\n res.on('data', (chunk) => { rawData += chunk; });\n res.on('end', () => {\n try {\n const parsedData = JSON.parse(rawData);\n console.log(parsedData);\n } catch (e) {\n console.error(e.message);\n }\n });\n}).on('error', (e) => {\n console.error(`Got error: ${e.message}`);\n});\n\n// Create a local server to receive data from\nconst server = http.createServer((req, res) => {\n res.writeHead(200, { 'Content-Type': 'application/json' });\n res.end(JSON.stringify({\n data: 'Hello World!'\n }));\n});\n\nserver.listen(8000);\nNode.js maintains several connections per server to make HTTP requests.\nThis function allows one to transparently issue requests.
\nurl can be a string or a URL object. If url is a\nstring, it is automatically parsed with new URL(). If it is a URL\nobject, it will be automatically converted to an ordinary options object.
If both url and options are specified, the objects are merged, with the\noptions properties taking precedence.
The optional callback parameter will be added as a one-time listener for\nthe 'response' event.
http.request() returns an instance of the http.ClientRequest\nclass. The ClientRequest instance is a writable stream. If one needs to\nupload a file with a POST request, then write to the ClientRequest object.
const http = require('http');\n\nconst postData = JSON.stringify({\n 'msg': 'Hello World!'\n});\n\nconst options = {\n hostname: 'www.google.com',\n port: 80,\n path: '/upload',\n method: 'POST',\n headers: {\n 'Content-Type': 'application/json',\n 'Content-Length': Buffer.byteLength(postData)\n }\n};\n\nconst req = http.request(options, (res) => {\n console.log(`STATUS: ${res.statusCode}`);\n console.log(`HEADERS: ${JSON.stringify(res.headers)}`);\n res.setEncoding('utf8');\n res.on('data', (chunk) => {\n console.log(`BODY: ${chunk}`);\n });\n res.on('end', () => {\n console.log('No more data in response.');\n });\n});\n\nreq.on('error', (e) => {\n console.error(`problem with request: ${e.message}`);\n});\n\n// Write data to request body\nreq.write(postData);\nreq.end();\nIn the example req.end() was called. With http.request() one\nmust always call req.end() to signify the end of the request -\neven if there is no data being written to the request body.
If any error is encountered during the request (be that with DNS resolution,\nTCP level errors, or actual HTTP parse errors) an 'error' event is emitted\non the returned request object. As with all 'error' events, if no listeners\nare registered the error will be thrown.
There are a few special headers that should be noted.
\nSending a 'Connection: keep-alive' will notify Node.js that the connection to\nthe server should be persisted until the next request.
\nSending a 'Content-Length' header will disable the default chunked encoding.
\nSending an 'Expect' header will immediately send the request headers.\nUsually, when sending 'Expect: 100-continue', both a timeout and a listener\nfor the 'continue' event should be set. See RFC 2616 Section 8.2.3 for more\ninformation.
Sending an Authorization header will override using the auth option\nto compute basic authentication.
Example using a URL as options:
const options = new URL('http://abc:xyz@example.com');\n\nconst req = http.request(options, (res) => {\n // ...\n});\nIn a successful request, the following events will be emitted in the following\norder:
\n'socket''response'\n'data' any number of times, on the res object\n('data' will not be emitted at all if the response body is empty, for\ninstance, in most redirects)'end' on the res object'close'In the case of a connection error, the following events will be emitted:
\n'socket''error''close'In the case of a premature connection close before the response is received,\nthe following events will be emitted in the following order:
\n'socket''error' with an error with message 'Error: socket hang up' and code\n'ECONNRESET''close'In the case of a premature connection close after the response is received,\nthe following events will be emitted in the following order:
\n'socket''response'\n'data' any number of times, on the res object'aborted' on the res object'error' on the res object with an error with message\n'Error: aborted' and code 'ECONNRESET'.'close''close' on the res objectIf req.destroy() is called before a socket is assigned, the following\nevents will be emitted in the following order:
req.destroy() called here)'error' with an error with message 'Error: socket hang up' and code\n'ECONNRESET''close'If req.destroy() is called before the connection succeeds, the following\nevents will be emitted in the following order:
'socket'req.destroy() called here)'error' with an error with message 'Error: socket hang up' and code\n'ECONNRESET''close'If req.destroy() is called after the response is received, the following\nevents will be emitted in the following order:
'socket''response'\n'data' any number of times, on the res objectreq.destroy() called here)'aborted' on the res object'error' on the res object with an error with message\n'Error: aborted' and code 'ECONNRESET'.'close''close' on the res objectIf req.abort() is called before a socket is assigned, the following\nevents will be emitted in the following order:
req.abort() called here)'abort''close'If req.abort() is called before the connection succeeds, the following\nevents will be emitted in the following order:
'socket'req.abort() called here)'abort''error' with an error with message 'Error: socket hang up' and code\n'ECONNRESET''close'If req.abort() is called after the response is received, the following\nevents will be emitted in the following order:
'socket''response'\n'data' any number of times, on the res objectreq.abort() called here)'abort''aborted' on the res object'error' on the res object with an error with message\n'Error: aborted' and code 'ECONNRESET'.'close''close' on the res objectSetting the timeout option or using the setTimeout() function will\nnot abort the request or do anything besides add a 'timeout' event.
Passing an AbortSignal and then calling abort on the corresponding\nAbortController will behave the same way as calling .destroy() on the\nrequest itself.
Node.js maintains several connections per server to make HTTP requests.\nThis function allows one to transparently issue requests.
\nurl can be a string or a URL object. If url is a\nstring, it is automatically parsed with new URL(). If it is a URL\nobject, it will be automatically converted to an ordinary options object.
If both url and options are specified, the objects are merged, with the\noptions properties taking precedence.
The optional callback parameter will be added as a one-time listener for\nthe 'response' event.
http.request() returns an instance of the http.ClientRequest\nclass. The ClientRequest instance is a writable stream. If one needs to\nupload a file with a POST request, then write to the ClientRequest object.
const http = require('http');\n\nconst postData = JSON.stringify({\n 'msg': 'Hello World!'\n});\n\nconst options = {\n hostname: 'www.google.com',\n port: 80,\n path: '/upload',\n method: 'POST',\n headers: {\n 'Content-Type': 'application/json',\n 'Content-Length': Buffer.byteLength(postData)\n }\n};\n\nconst req = http.request(options, (res) => {\n console.log(`STATUS: ${res.statusCode}`);\n console.log(`HEADERS: ${JSON.stringify(res.headers)}`);\n res.setEncoding('utf8');\n res.on('data', (chunk) => {\n console.log(`BODY: ${chunk}`);\n });\n res.on('end', () => {\n console.log('No more data in response.');\n });\n});\n\nreq.on('error', (e) => {\n console.error(`problem with request: ${e.message}`);\n});\n\n// Write data to request body\nreq.write(postData);\nreq.end();\nIn the example req.end() was called. With http.request() one\nmust always call req.end() to signify the end of the request -\neven if there is no data being written to the request body.
If any error is encountered during the request (be that with DNS resolution,\nTCP level errors, or actual HTTP parse errors) an 'error' event is emitted\non the returned request object. As with all 'error' events, if no listeners\nare registered the error will be thrown.
There are a few special headers that should be noted.
\nSending a 'Connection: keep-alive' will notify Node.js that the connection to\nthe server should be persisted until the next request.
\nSending a 'Content-Length' header will disable the default chunked encoding.
\nSending an 'Expect' header will immediately send the request headers.\nUsually, when sending 'Expect: 100-continue', both a timeout and a listener\nfor the 'continue' event should be set. See RFC 2616 Section 8.2.3 for more\ninformation.
Sending an Authorization header will override using the auth option\nto compute basic authentication.
Example using a URL as options:
const options = new URL('http://abc:xyz@example.com');\n\nconst req = http.request(options, (res) => {\n // ...\n});\nIn a successful request, the following events will be emitted in the following\norder:
\n'socket''response'\n'data' any number of times, on the res object\n('data' will not be emitted at all if the response body is empty, for\ninstance, in most redirects)'end' on the res object'close'In the case of a connection error, the following events will be emitted:
\n'socket''error''close'In the case of a premature connection close before the response is received,\nthe following events will be emitted in the following order:
\n'socket''error' with an error with message 'Error: socket hang up' and code\n'ECONNRESET''close'In the case of a premature connection close after the response is received,\nthe following events will be emitted in the following order:
\n'socket''response'\n'data' any number of times, on the res object'aborted' on the res object'error' on the res object with an error with message\n'Error: aborted' and code 'ECONNRESET'.'close''close' on the res objectIf req.destroy() is called before a socket is assigned, the following\nevents will be emitted in the following order:
req.destroy() called here)'error' with an error with message 'Error: socket hang up' and code\n'ECONNRESET''close'If req.destroy() is called before the connection succeeds, the following\nevents will be emitted in the following order:
'socket'req.destroy() called here)'error' with an error with message 'Error: socket hang up' and code\n'ECONNRESET''close'If req.destroy() is called after the response is received, the following\nevents will be emitted in the following order:
'socket''response'\n'data' any number of times, on the res objectreq.destroy() called here)'aborted' on the res object'error' on the res object with an error with message\n'Error: aborted' and code 'ECONNRESET'.'close''close' on the res objectIf req.abort() is called before a socket is assigned, the following\nevents will be emitted in the following order:
req.abort() called here)'abort''close'If req.abort() is called before the connection succeeds, the following\nevents will be emitted in the following order:
'socket'req.abort() called here)'abort''error' with an error with message 'Error: socket hang up' and code\n'ECONNRESET''close'If req.abort() is called after the response is received, the following\nevents will be emitted in the following order:
'socket''response'\n'data' any number of times, on the res objectreq.abort() called here)'abort''aborted' on the res object'error' on the res object with an error with message\n'Error: aborted' and code 'ECONNRESET'.'close''close' on the res objectSetting the timeout option or using the setTimeout() function will\nnot abort the request or do anything besides add a 'timeout' event.
Passing an AbortSignal and then calling abort on the corresponding\nAbortController will behave the same way as calling .destroy() on the\nrequest itself.
Performs the low-level validations on the provided name that are done when\nres.setHeader(name, value) is called.
Passing illegal value as name will result in a TypeError being thrown,\nidentified by code: 'ERR_INVALID_HTTP_TOKEN'.
It is not necessary to use this method before passing headers to an HTTP request\nor response. The HTTP module will automatically validate such headers.\nExamples:
\nExample:
\nconst { validateHeaderName } = require('http');\n\ntry {\n validateHeaderName('');\n} catch (err) {\n err instanceof TypeError; // --> true\n err.code; // --> 'ERR_INVALID_HTTP_TOKEN'\n err.message; // --> 'Header name must be a valid HTTP token [\"\"]'\n}\nPerforms the low-level validations on the provided value that are done when\nres.setHeader(name, value) is called.
Passing illegal value as value will result in a TypeError being thrown.
code: 'ERR_HTTP_INVALID_HEADER_VALUE'.code: 'ERR_INVALID_CHAR'.It is not necessary to use this method before passing headers to an HTTP request\nor response. The HTTP module will automatically validate such headers.
\nExamples:
\nconst { validateHeaderValue } = require('http');\n\ntry {\n validateHeaderValue('x-my-header', undefined);\n} catch (err) {\n err instanceof TypeError; // --> true\n err.code === 'ERR_HTTP_INVALID_HEADER_VALUE'; // --> true\n err.message; // --> 'Invalid value \"undefined\" for header \"x-my-header\"'\n}\n\ntry {\n validateHeaderValue('x-my-header', 'oʊmɪɡə');\n} catch (err) {\n err instanceof TypeError; // --> true\n err.code === 'ERR_INVALID_CHAR'; // --> true\n err.message; // --> 'Invalid character in header content [\"x-my-header\"]'\n}\n