Upload 799 files

748250d almost 3 years ago

17.6 kB

var url = require("url");
var URL = url.URL;
var http = require("http");
var https = require("https");
var Writable = require("stream").Writable;
var assert = require("assert");
var debug = require("./debug");

// Create handlers that pass events from native requests
var events = ["abort", "aborted", "connect", "error", "socket", "timeout"];
var eventHandlers = Object.create(null);
events.forEach(function (event) {
  eventHandlers[event] = function (arg1, arg2, arg3) {
    this._redirectable.emit(event, arg1, arg2, arg3);
  };
});

// Error types with codes
var RedirectionError = createErrorType(
  "ERR_FR_REDIRECTION_FAILURE",
  "Redirected request failed"
);
var TooManyRedirectsError = createErrorType(
  "ERR_FR_TOO_MANY_REDIRECTS",
  "Maximum number of redirects exceeded"
);
var MaxBodyLengthExceededError = createErrorType(
  "ERR_FR_MAX_BODY_LENGTH_EXCEEDED",
  "Request body larger than maxBodyLength limit"
);
var WriteAfterEndError = createErrorType(
  "ERR_STREAM_WRITE_AFTER_END",
  "write after end"
);

// An HTTP(S) request that can be redirected
function RedirectableRequest(options, responseCallback) {
  // Initialize the request
  Writable.call(this);
  this._sanitizeOptions(options);
  this._options = options;
  this._ended = false;
  this._ending = false;
  this._redirectCount = 0;
  this._redirects = [];
  this._requestBodyLength = 0;
  this._requestBodyBuffers = [];

  // Attach a callback if passed
  if (responseCallback) {
    this.on("response", responseCallback);
  }

  // React to responses of native requests
  var self = this;
  this._onNativeResponse = function (response) {
    self._processResponse(response);
  };

  // Perform the first request
  this._performRequest();
}
RedirectableRequest.prototype = Object.create(Writable.prototype);

RedirectableRequest.prototype.abort = function () {
  abortRequest(this._currentRequest);
  this.emit("abort");
};

// Writes buffered data to the current native request
RedirectableRequest.prototype.write = function (data, encoding, callback) {
  // Writing is not allowed if end has been called
  if (this._ending) {
    throw new WriteAfterEndError();
  }

  // Validate input and shift parameters if necessary
  if (!(typeof data === "string" || typeof data === "object" && ("length" in data))) {
    throw new TypeError("data should be a string, Buffer or Uint8Array");
  }
  if (typeof encoding === "function") {
    callback = encoding;
    encoding = null;
  }

  // Ignore empty buffers, since writing them doesn't invoke the callback
  // https://github.com/nodejs/node/issues/22066
  if (data.length === 0) {
    if (callback) {
      callback();
    }
    return;
  }
  // Only write when we don't exceed the maximum body length
  if (this._requestBodyLength + data.length <= this._options.maxBodyLength) {
    this._requestBodyLength += data.length;
    this._requestBodyBuffers.push({ data: data, encoding: encoding });
    this._currentRequest.write(data, encoding, callback);
  }
  // Error when we exceed the maximum body length
  else {
    this.emit("error", new MaxBodyLengthExceededError());
    this.abort();
  }
};

// Ends the current native request
RedirectableRequest.prototype.end = function (data, encoding, callback) {
  // Shift parameters if necessary
  if (typeof data === "function") {
    callback = data;
    data = encoding = null;
  }
  else if (typeof encoding === "function") {
    callback = encoding;
    encoding = null;
  }

  // Write data if needed and end
  if (!data) {
    this._ended = this._ending = true;
    this._currentRequest.end(null, null, callback);
  }
  else {
    var self = this;
    var currentRequest = this._currentRequest;
    this.write(data, encoding, function () {
      self._ended = true;
      currentRequest.end(null, null, callback);
    });
    this._ending = true;
  }
};

// Sets a header value on the current native request
RedirectableRequest.prototype.setHeader = function (name, value) {
  this._options.headers[name] = value;
  this._currentRequest.setHeader(name, value);
};

// Clears a header value on the current native request
RedirectableRequest.prototype.removeHeader = function (name) {
  delete this._options.headers[name];
  this._currentRequest.removeHeader(name);
};

// Global timeout for all underlying requests
RedirectableRequest.prototype.setTimeout = function (msecs, callback) {
  var self = this;

  // Destroys the socket on timeout
  function destroyOnTimeout(socket) {
    socket.setTimeout(msecs);
    socket.removeListener("timeout", socket.destroy);
    socket.addListener("timeout", socket.destroy);
  }

  // Sets up a timer to trigger a timeout event
  function startTimer(socket) {
    if (self._timeout) {
      clearTimeout(self._timeout);
    }
    self._timeout = setTimeout(function () {
      self.emit("timeout");
      clearTimer();
    }, msecs);
    destroyOnTimeout(socket);
  }

  // Stops a timeout from triggering
  function clearTimer() {
    // Clear the timeout
    if (self._timeout) {
      clearTimeout(self._timeout);
      self._timeout = null;
    }

    // Clean up all attached listeners
    self.removeListener("abort", clearTimer);
    self.removeListener("error", clearTimer);
    self.removeListener("response", clearTimer);
    if (callback) {
      self.removeListener("timeout", callback);
    }
    if (!self.socket) {
      self._currentRequest.removeListener("socket", startTimer);
    }
  }

  // Attach callback if passed
  if (callback) {
    this.on("timeout", callback);
  }

  // Start the timer if or when the socket is opened
  if (this.socket) {
    startTimer(this.socket);
  }
  else {
    this._currentRequest.once("socket", startTimer);
  }

  // Clean up on events
  this.on("socket", destroyOnTimeout);
  this.on("abort", clearTimer);
  this.on("error", clearTimer);
  this.on("response", clearTimer);

  return this;
};

// Proxy all other public ClientRequest methods
[
  "flushHeaders", "getHeader",
  "setNoDelay", "setSocketKeepAlive",
].forEach(function (method) {
  RedirectableRequest.prototype[method] = function (a, b) {
    return this._currentRequest[method](a, b);
  };
});

// Proxy all public ClientRequest properties
["aborted", "connection", "socket"].forEach(function (property) {
  Object.defineProperty(RedirectableRequest.prototype, property, {
    get: function () { return this._currentRequest[property]; },
  });
});

RedirectableRequest.prototype._sanitizeOptions = function (options) {
  // Ensure headers are always present
  if (!options.headers) {
    options.headers = {};
  }

  // Since http.request treats host as an alias of hostname,
  // but the url module interprets host as hostname plus port,
  // eliminate the host property to avoid confusion.
  if (options.host) {
    // Use hostname if set, because it has precedence
    if (!options.hostname) {
      options.hostname = options.host;
    }
    delete options.host;
  }

  // Complete the URL object when necessary
  if (!options.pathname && options.path) {
    var searchPos = options.path.indexOf("?");
    if (searchPos < 0) {
      options.pathname = options.path;
    }
    else {
      options.pathname = options.path.substring(0, searchPos);
      options.search = options.path.substring(searchPos);
    }
  }
};


// Executes the next native request (initial or redirect)
RedirectableRequest.prototype._performRequest = function () {
  // Load the native protocol
  var protocol = this._options.protocol;
  var nativeProtocol = this._options.nativeProtocols[protocol];
  if (!nativeProtocol) {
    this.emit("error", new TypeError("Unsupported protocol " + protocol));
    return;
  }

  // If specified, use the agent corresponding to the protocol
  // (HTTP and HTTPS use different types of agents)
  if (this._options.agents) {
    var scheme = protocol.substr(0, protocol.length - 1);
    this._options.agent = this._options.agents[scheme];
  }

  // Create the native request
  var request = this._currentRequest =
        nativeProtocol.request(this._options, this._onNativeResponse);
  this._currentUrl = url.format(this._options);

  // Set up event handlers
  request._redirectable = this;
  for (var e = 0; e < events.length; e++) {
    request.on(events[e], eventHandlers[events[e]]);
  }

  // End a redirected request
  // (The first request must be ended explicitly with RedirectableRequest#end)
  if (this._isRedirect) {
    // Write the request entity and end.
    var i = 0;
    var self = this;
    var buffers = this._requestBodyBuffers;
    (function writeNext(error) {
      // Only write if this request has not been redirected yet
      /* istanbul ignore else */
      if (request === self._currentRequest) {
        // Report any write errors
        /* istanbul ignore if */
        if (error) {
          self.emit("error", error);
        }
        // Write the next buffer if there are still left
        else if (i < buffers.length) {
          var buffer = buffers[i++];
          /* istanbul ignore else */
          if (!request.finished) {
            request.write(buffer.data, buffer.encoding, writeNext);
          }
        }
        // End the request if `end` has been called on us
        else if (self._ended) {
          request.end();
        }
      }
    }());
  }
};

// Processes a response from the current native request
RedirectableRequest.prototype._processResponse = function (response) {
  // Store the redirected response
  var statusCode = response.statusCode;
  if (this._options.trackRedirects) {
    this._redirects.push({
      url: this._currentUrl,
      headers: response.headers,
      statusCode: statusCode,
    });
  }

  // RFC7231§6.4: The 3xx (Redirection) class of status code indicates
  // that further action needs to be taken by the user agent in order to
  // fulfill the request. If a Location header field is provided,
  // the user agent MAY automatically redirect its request to the URI
  // referenced by the Location field value,
  // even if the specific status code is not understood.

  // If the response is not a redirect; return it as-is
  var location = response.headers.location;
  if (!location || this._options.followRedirects === false ||
      statusCode < 300 || statusCode >= 400) {
    response.responseUrl = this._currentUrl;
    response.redirects = this._redirects;
    this.emit("response", response);

    // Clean up
    this._requestBodyBuffers = [];
    return;
  }

  // The response is a redirect, so abort the current request
  abortRequest(this._currentRequest);
  // Discard the remainder of the response to avoid waiting for data
  response.destroy();

  // RFC7231§6.4: A client SHOULD detect and intervene
  // in cyclical redirections (i.e., "infinite" redirection loops).
  if (++this._redirectCount > this._options.maxRedirects) {
    this.emit("error", new TooManyRedirectsError());
    return;
  }

  // RFC7231§6.4: Automatic redirection needs to done with
  // care for methods not known to be safe, […]
  // RFC7231§6.4.2–3: For historical reasons, a user agent MAY change
  // the request method from POST to GET for the subsequent request.
  if ((statusCode === 301 || statusCode === 302) && this._options.method === "POST" ||
      // RFC7231§6.4.4: The 303 (See Other) status code indicates that
      // the server is redirecting the user agent to a different resource […]
      // A user agent can perform a retrieval request targeting that URI
      // (a GET or HEAD request if using HTTP) […]
      (statusCode === 303) && !/^(?:GET|HEAD)$/.test(this._options.method)) {
    this._options.method = "GET";
    // Drop a possible entity and headers related to it
    this._requestBodyBuffers = [];
    removeMatchingHeaders(/^content-/i, this._options.headers);
  }

  // Drop the Host header, as the redirect might lead to a different host
  var currentHostHeader = removeMatchingHeaders(/^host$/i, this._options.headers);

  // If the redirect is relative, carry over the host of the last request
  var currentUrlParts = url.parse(this._currentUrl);
  var currentHost = currentHostHeader || currentUrlParts.host;
  var currentUrl = /^\w+:/.test(location) ? this._currentUrl :
    url.format(Object.assign(currentUrlParts, { host: currentHost }));

  // Determine the URL of the redirection
  var redirectUrl;
  try {
    redirectUrl = url.resolve(currentUrl, location);
  }
  catch (cause) {
    this.emit("error", new RedirectionError(cause));
    return;
  }

  // Create the redirected request
  debug("redirecting to", redirectUrl);
  this._isRedirect = true;
  var redirectUrlParts = url.parse(redirectUrl);
  Object.assign(this._options, redirectUrlParts);

  // Drop confidential headers when redirecting to a less secure protocol
  // or to a different domain that is not a superdomain
  if (redirectUrlParts.protocol !== currentUrlParts.protocol &&
     redirectUrlParts.protocol !== "https:" ||
     redirectUrlParts.host !== currentHost &&
     !isSubdomain(redirectUrlParts.host, currentHost)) {
    removeMatchingHeaders(/^(?:authorization|cookie)$/i, this._options.headers);
  }

  // Evaluate the beforeRedirect callback
  if (typeof this._options.beforeRedirect === "function") {
    var responseDetails = { headers: response.headers };
    try {
      this._options.beforeRedirect.call(null, this._options, responseDetails);
    }
    catch (err) {
      this.emit("error", err);
      return;
    }
    this._sanitizeOptions(this._options);
  }

  // Perform the redirected request
  try {
    this._performRequest();
  }
  catch (cause) {
    this.emit("error", new RedirectionError(cause));
  }
};

// Wraps the key/value object of protocols with redirect functionality
function wrap(protocols) {
  // Default settings
  var exports = {
    maxRedirects: 21,
    maxBodyLength: 10 * 1024 * 1024,
  };

  // Wrap each protocol
  var nativeProtocols = {};
  Object.keys(protocols).forEach(function (scheme) {
    var protocol = scheme + ":";
    var nativeProtocol = nativeProtocols[protocol] = protocols[scheme];
    var wrappedProtocol = exports[scheme] = Object.create(nativeProtocol);

    // Executes a request, following redirects
    function request(input, options, callback) {
      // Parse parameters
      if (typeof input === "string") {
        var urlStr = input;
        try {
          input = urlToOptions(new URL(urlStr));
        }
        catch (err) {
          /* istanbul ignore next */
          input = url.parse(urlStr);
        }
      }
      else if (URL && (input instanceof URL)) {
        input = urlToOptions(input);
      }
      else {
        callback = options;
        options = input;
        input = { protocol: protocol };
      }
      if (typeof options === "function") {
        callback = options;
        options = null;
      }

      // Set defaults
      options = Object.assign({
        maxRedirects: exports.maxRedirects,
        maxBodyLength: exports.maxBodyLength,
      }, input, options);
      options.nativeProtocols = nativeProtocols;

      assert.equal(options.protocol, protocol, "protocol mismatch");
      debug("options", options);
      return new RedirectableRequest(options, callback);
    }

    // Executes a GET request, following redirects
    function get(input, options, callback) {
      var wrappedRequest = wrappedProtocol.request(input, options, callback);
      wrappedRequest.end();
      return wrappedRequest;
    }

    // Expose the properties on the wrapped protocol
    Object.defineProperties(wrappedProtocol, {
      request: { value: request, configurable: true, enumerable: true, writable: true },
      get: { value: get, configurable: true, enumerable: true, writable: true },
    });
  });
  return exports;
}

/* istanbul ignore next */
function noop() { /* empty */ }

// from https://github.com/nodejs/node/blob/master/lib/internal/url.js
function urlToOptions(urlObject) {
  var options = {
    protocol: urlObject.protocol,
    hostname: urlObject.hostname.startsWith("[") ?
      /* istanbul ignore next */
      urlObject.hostname.slice(1, -1) :
      urlObject.hostname,
    hash: urlObject.hash,
    search: urlObject.search,
    pathname: urlObject.pathname,
    path: urlObject.pathname + urlObject.search,
    href: urlObject.href,
  };
  if (urlObject.port !== "") {
    options.port = Number(urlObject.port);
  }
  return options;
}

function removeMatchingHeaders(regex, headers) {
  var lastValue;
  for (var header in headers) {
    if (regex.test(header)) {
      lastValue = headers[header];
      delete headers[header];
    }
  }
  return (lastValue === null || typeof lastValue === "undefined") ?
    undefined : String(lastValue).trim();
}

function createErrorType(code, defaultMessage) {
  function CustomError(cause) {
    Error.captureStackTrace(this, this.constructor);
    if (!cause) {
      this.message = defaultMessage;
    }
    else {
      this.message = defaultMessage + ": " + cause.message;
      this.cause = cause;
    }
  }
  CustomError.prototype = new Error();
  CustomError.prototype.constructor = CustomError;
  CustomError.prototype.name = "Error [" + code + "]";
  CustomError.prototype.code = code;
  return CustomError;
}

function abortRequest(request) {
  for (var e = 0; e < events.length; e++) {
    request.removeListener(events[e], eventHandlers[events[e]]);
  }
  request.on("error", noop);
  request.abort();
}

function isSubdomain(subdomain, domain) {
  const dot = subdomain.length - domain.length - 1;
  return dot > 0 && subdomain[dot] === "." && subdomain.endsWith(domain);
}

// Exports
module.exports = wrap({ http: http, https: https });
module.exports.wrap = wrap;

	var url = require("url");
	var URL = url.URL;
	var http = require("http");
	var https = require("https");
	var Writable = require("stream").Writable;
	var assert = require("assert");
	var debug = require("./debug");

	// Create handlers that pass events from native requests
	var events = ["abort", "aborted", "connect", "error", "socket", "timeout"];
	var eventHandlers = Object.create(null);
	events.forEach(function (event) {
	eventHandlers[event] = function (arg1, arg2, arg3) {
	this._redirectable.emit(event, arg1, arg2, arg3);
	};
	});

	// Error types with codes
	var RedirectionError = createErrorType(
	"ERR_FR_REDIRECTION_FAILURE",
	"Redirected request failed"
	);
	var TooManyRedirectsError = createErrorType(
	"ERR_FR_TOO_MANY_REDIRECTS",
	"Maximum number of redirects exceeded"
	);
	var MaxBodyLengthExceededError = createErrorType(
	"ERR_FR_MAX_BODY_LENGTH_EXCEEDED",
	"Request body larger than maxBodyLength limit"
	);
	var WriteAfterEndError = createErrorType(
	"ERR_STREAM_WRITE_AFTER_END",
	"write after end"
	);

	// An HTTP(S) request that can be redirected
	function RedirectableRequest(options, responseCallback) {
	// Initialize the request
	Writable.call(this);
	this._sanitizeOptions(options);
	this._options = options;
	this._ended = false;
	this._ending = false;
	this._redirectCount = 0;
	this._redirects = [];
	this._requestBodyLength = 0;
	this._requestBodyBuffers = [];

	// Attach a callback if passed
	if (responseCallback) {
	this.on("response", responseCallback);
	}

	// React to responses of native requests
	var self = this;
	this._onNativeResponse = function (response) {
	self._processResponse(response);
	};

	// Perform the first request
	this._performRequest();
	}
	RedirectableRequest.prototype = Object.create(Writable.prototype);

	RedirectableRequest.prototype.abort = function () {
	abortRequest(this._currentRequest);
	this.emit("abort");
	};

	// Writes buffered data to the current native request
	RedirectableRequest.prototype.write = function (data, encoding, callback) {
	// Writing is not allowed if end has been called
	if (this._ending) {
	throw new WriteAfterEndError();
	}

	// Validate input and shift parameters if necessary
	if (!(typeof data === "string" \|\| typeof data === "object" && ("length" in data))) {
	throw new TypeError("data should be a string, Buffer or Uint8Array");
	}
	if (typeof encoding === "function") {
	callback = encoding;
	encoding = null;
	}

	// Ignore empty buffers, since writing them doesn't invoke the callback
	// https://github.com/nodejs/node/issues/22066
	if (data.length === 0) {
	if (callback) {
	callback();
	}
	return;
	}
	// Only write when we don't exceed the maximum body length
	if (this._requestBodyLength + data.length <= this._options.maxBodyLength) {
	this._requestBodyLength += data.length;
	this._requestBodyBuffers.push({ data: data, encoding: encoding });
	this._currentRequest.write(data, encoding, callback);
	}
	// Error when we exceed the maximum body length
	else {
	this.emit("error", new MaxBodyLengthExceededError());
	this.abort();
	}
	};

	// Ends the current native request
	RedirectableRequest.prototype.end = function (data, encoding, callback) {
	// Shift parameters if necessary
	if (typeof data === "function") {
	callback = data;
	data = encoding = null;
	}
	else if (typeof encoding === "function") {
	callback = encoding;
	encoding = null;
	}

	// Write data if needed and end
	if (!data) {
	this._ended = this._ending = true;
	this._currentRequest.end(null, null, callback);
	}
	else {
	var self = this;
	var currentRequest = this._currentRequest;
	this.write(data, encoding, function () {
	self._ended = true;
	currentRequest.end(null, null, callback);
	});
	this._ending = true;
	}
	};

	// Sets a header value on the current native request
	RedirectableRequest.prototype.setHeader = function (name, value) {
	this._options.headers[name] = value;
	this._currentRequest.setHeader(name, value);
	};

	// Clears a header value on the current native request
	RedirectableRequest.prototype.removeHeader = function (name) {
	delete this._options.headers[name];
	this._currentRequest.removeHeader(name);
	};

	// Global timeout for all underlying requests
	RedirectableRequest.prototype.setTimeout = function (msecs, callback) {
	var self = this;

	// Destroys the socket on timeout
	function destroyOnTimeout(socket) {
	socket.setTimeout(msecs);
	socket.removeListener("timeout", socket.destroy);
	socket.addListener("timeout", socket.destroy);
	}

	// Sets up a timer to trigger a timeout event
	function startTimer(socket) {
	if (self._timeout) {
	clearTimeout(self._timeout);
	}
	self._timeout = setTimeout(function () {
	self.emit("timeout");
	clearTimer();
	}, msecs);
	destroyOnTimeout(socket);
	}

	// Stops a timeout from triggering
	function clearTimer() {
	// Clear the timeout
	if (self._timeout) {
	clearTimeout(self._timeout);
	self._timeout = null;
	}

	// Clean up all attached listeners
	self.removeListener("abort", clearTimer);
	self.removeListener("error", clearTimer);
	self.removeListener("response", clearTimer);
	if (callback) {
	self.removeListener("timeout", callback);
	}
	if (!self.socket) {
	self._currentRequest.removeListener("socket", startTimer);
	}
	}

	// Attach callback if passed
	if (callback) {
	this.on("timeout", callback);
	}

	// Start the timer if or when the socket is opened
	if (this.socket) {
	startTimer(this.socket);
	}
	else {
	this._currentRequest.once("socket", startTimer);
	}

	// Clean up on events
	this.on("socket", destroyOnTimeout);
	this.on("abort", clearTimer);
	this.on("error", clearTimer);
	this.on("response", clearTimer);

	return this;
	};

	// Proxy all other public ClientRequest methods
	[
	"flushHeaders", "getHeader",
	"setNoDelay", "setSocketKeepAlive",
	].forEach(function (method) {
	RedirectableRequest.prototype[method] = function (a, b) {
	return this._currentRequest[method](a, b);
	};
	});

	// Proxy all public ClientRequest properties
	["aborted", "connection", "socket"].forEach(function (property) {
	Object.defineProperty(RedirectableRequest.prototype, property, {
	get: function () { return this._currentRequest[property]; },
	});
	});

	RedirectableRequest.prototype._sanitizeOptions = function (options) {
	// Ensure headers are always present
	if (!options.headers) {
	options.headers = {};
	}

	// Since http.request treats host as an alias of hostname,
	// but the url module interprets host as hostname plus port,
	// eliminate the host property to avoid confusion.
	if (options.host) {
	// Use hostname if set, because it has precedence
	if (!options.hostname) {
	options.hostname = options.host;
	}
	delete options.host;
	}

	// Complete the URL object when necessary
	if (!options.pathname && options.path) {
	var searchPos = options.path.indexOf("?");
	if (searchPos < 0) {
	options.pathname = options.path;
	}
	else {
	options.pathname = options.path.substring(0, searchPos);
	options.search = options.path.substring(searchPos);
	}
	}
	};


	// Executes the next native request (initial or redirect)
	RedirectableRequest.prototype._performRequest = function () {
	// Load the native protocol
	var protocol = this._options.protocol;
	var nativeProtocol = this._options.nativeProtocols[protocol];
	if (!nativeProtocol) {
	this.emit("error", new TypeError("Unsupported protocol " + protocol));
	return;
	}

	// If specified, use the agent corresponding to the protocol
	// (HTTP and HTTPS use different types of agents)
	if (this._options.agents) {
	var scheme = protocol.substr(0, protocol.length - 1);
	this._options.agent = this._options.agents[scheme];
	}

	// Create the native request
	var request = this._currentRequest =
	nativeProtocol.request(this._options, this._onNativeResponse);
	this._currentUrl = url.format(this._options);

	// Set up event handlers
	request._redirectable = this;
	for (var e = 0; e < events.length; e++) {
	request.on(events[e], eventHandlers[events[e]]);
	}

	// End a redirected request
	// (The first request must be ended explicitly with RedirectableRequest#end)
	if (this._isRedirect) {
	// Write the request entity and end.
	var i = 0;
	var self = this;
	var buffers = this._requestBodyBuffers;
	(function writeNext(error) {
	// Only write if this request has not been redirected yet
	/* istanbul ignore else */
	if (request === self._currentRequest) {
	// Report any write errors
	/* istanbul ignore if */
	if (error) {
	self.emit("error", error);
	}
	// Write the next buffer if there are still left
	else if (i < buffers.length) {
	var buffer = buffers[i++];
	/* istanbul ignore else */
	if (!request.finished) {
	request.write(buffer.data, buffer.encoding, writeNext);
	}
	}
	// End the request if `end` has been called on us
	else if (self._ended) {
	request.end();
	}
	}
	}());
	}
	};

	// Processes a response from the current native request
	RedirectableRequest.prototype._processResponse = function (response) {
	// Store the redirected response
	var statusCode = response.statusCode;
	if (this._options.trackRedirects) {
	this._redirects.push({
	url: this._currentUrl,
	headers: response.headers,
	statusCode: statusCode,
	});
	}

	// RFC7231§6.4: The 3xx (Redirection) class of status code indicates
	// that further action needs to be taken by the user agent in order to
	// fulfill the request. If a Location header field is provided,
	// the user agent MAY automatically redirect its request to the URI
	// referenced by the Location field value,
	// even if the specific status code is not understood.

	// If the response is not a redirect; return it as-is
	var location = response.headers.location;
	if (!location \|\| this._options.followRedirects === false \|\|
	statusCode < 300 \|\| statusCode >= 400) {
	response.responseUrl = this._currentUrl;
	response.redirects = this._redirects;
	this.emit("response", response);

	// Clean up
	this._requestBodyBuffers = [];
	return;
	}

	// The response is a redirect, so abort the current request
	abortRequest(this._currentRequest);
	// Discard the remainder of the response to avoid waiting for data
	response.destroy();

	// RFC7231§6.4: A client SHOULD detect and intervene
	// in cyclical redirections (i.e., "infinite" redirection loops).
	if (++this._redirectCount > this._options.maxRedirects) {
	this.emit("error", new TooManyRedirectsError());
	return;
	}

	// RFC7231§6.4: Automatic redirection needs to done with
	// care for methods not known to be safe, […]
	// RFC7231§6.4.2–3: For historical reasons, a user agent MAY change
	// the request method from POST to GET for the subsequent request.
	if ((statusCode === 301 \|\| statusCode === 302) && this._options.method === "POST" \|\|
	// RFC7231§6.4.4: The 303 (See Other) status code indicates that
	// the server is redirecting the user agent to a different resource […]
	// A user agent can perform a retrieval request targeting that URI
	// (a GET or HEAD request if using HTTP) […]
	(statusCode === 303) && !/^(?:GET\|HEAD)$/.test(this._options.method)) {
	this._options.method = "GET";
	// Drop a possible entity and headers related to it
	this._requestBodyBuffers = [];
	removeMatchingHeaders(/^content-/i, this._options.headers);
	}

	// Drop the Host header, as the redirect might lead to a different host
	var currentHostHeader = removeMatchingHeaders(/^host$/i, this._options.headers);

	// If the redirect is relative, carry over the host of the last request
	var currentUrlParts = url.parse(this._currentUrl);
	var currentHost = currentHostHeader \|\| currentUrlParts.host;
	var currentUrl = /^\w+:/.test(location) ? this._currentUrl :
	url.format(Object.assign(currentUrlParts, { host: currentHost }));

	// Determine the URL of the redirection
	var redirectUrl;
	try {
	redirectUrl = url.resolve(currentUrl, location);
	}
	catch (cause) {
	this.emit("error", new RedirectionError(cause));
	return;
	}

	// Create the redirected request
	debug("redirecting to", redirectUrl);
	this._isRedirect = true;
	var redirectUrlParts = url.parse(redirectUrl);
	Object.assign(this._options, redirectUrlParts);

	// Drop confidential headers when redirecting to a less secure protocol
	// or to a different domain that is not a superdomain
	if (redirectUrlParts.protocol !== currentUrlParts.protocol &&
	redirectUrlParts.protocol !== "https:" \|\|
	redirectUrlParts.host !== currentHost &&
	!isSubdomain(redirectUrlParts.host, currentHost)) {
	removeMatchingHeaders(/^(?:authorization\|cookie)$/i, this._options.headers);
	}

	// Evaluate the beforeRedirect callback
	if (typeof this._options.beforeRedirect === "function") {
	var responseDetails = { headers: response.headers };
	try {
	this._options.beforeRedirect.call(null, this._options, responseDetails);
	}
	catch (err) {
	this.emit("error", err);
	return;
	}
	this._sanitizeOptions(this._options);
	}

	// Perform the redirected request
	try {
	this._performRequest();
	}
	catch (cause) {
	this.emit("error", new RedirectionError(cause));
	}
	};

	// Wraps the key/value object of protocols with redirect functionality
	function wrap(protocols) {
	// Default settings
	var exports = {
	maxRedirects: 21,
	maxBodyLength: 10 * 1024 * 1024,
	};

	// Wrap each protocol
	var nativeProtocols = {};
	Object.keys(protocols).forEach(function (scheme) {
	var protocol = scheme + ":";
	var nativeProtocol = nativeProtocols[protocol] = protocols[scheme];
	var wrappedProtocol = exports[scheme] = Object.create(nativeProtocol);

	// Executes a request, following redirects
	function request(input, options, callback) {
	// Parse parameters
	if (typeof input === "string") {
	var urlStr = input;
	try {
	input = urlToOptions(new URL(urlStr));
	}
	catch (err) {
	/* istanbul ignore next */
	input = url.parse(urlStr);
	}
	}
	else if (URL && (input instanceof URL)) {
	input = urlToOptions(input);
	}
	else {
	callback = options;
	options = input;
	input = { protocol: protocol };
	}
	if (typeof options === "function") {
	callback = options;
	options = null;
	}

	// Set defaults
	options = Object.assign({
	maxRedirects: exports.maxRedirects,
	maxBodyLength: exports.maxBodyLength,
	}, input, options);
	options.nativeProtocols = nativeProtocols;

	assert.equal(options.protocol, protocol, "protocol mismatch");
	debug("options", options);
	return new RedirectableRequest(options, callback);
	}

	// Executes a GET request, following redirects
	function get(input, options, callback) {
	var wrappedRequest = wrappedProtocol.request(input, options, callback);
	wrappedRequest.end();
	return wrappedRequest;
	}

	// Expose the properties on the wrapped protocol
	Object.defineProperties(wrappedProtocol, {
	request: { value: request, configurable: true, enumerable: true, writable: true },
	get: { value: get, configurable: true, enumerable: true, writable: true },
	});
	});
	return exports;
	}

	/* istanbul ignore next */
	function noop() { /* empty */ }

	// from https://github.com/nodejs/node/blob/master/lib/internal/url.js
	function urlToOptions(urlObject) {
	var options = {
	protocol: urlObject.protocol,
	hostname: urlObject.hostname.startsWith("[") ?
	/* istanbul ignore next */
	urlObject.hostname.slice(1, -1) :
	urlObject.hostname,
	hash: urlObject.hash,
	search: urlObject.search,
	pathname: urlObject.pathname,
	path: urlObject.pathname + urlObject.search,
	href: urlObject.href,
	};
	if (urlObject.port !== "") {
	options.port = Number(urlObject.port);
	}
	return options;
	}

	function removeMatchingHeaders(regex, headers) {
	var lastValue;
	for (var header in headers) {
	if (regex.test(header)) {
	lastValue = headers[header];
	delete headers[header];
	}
	}
	return (lastValue === null \|\| typeof lastValue === "undefined") ?
	undefined : String(lastValue).trim();
	}

	function createErrorType(code, defaultMessage) {
	function CustomError(cause) {
	Error.captureStackTrace(this, this.constructor);
	if (!cause) {
	this.message = defaultMessage;
	}
	else {
	this.message = defaultMessage + ": " + cause.message;
	this.cause = cause;
	}
	}
	CustomError.prototype = new Error();
	CustomError.prototype.constructor = CustomError;
	CustomError.prototype.name = "Error [" + code + "]";
	CustomError.prototype.code = code;
	return CustomError;
	}

	function abortRequest(request) {
	for (var e = 0; e < events.length; e++) {
	request.removeListener(events[e], eventHandlers[events[e]]);
	}
	request.on("error", noop);
	request.abort();
	}

	function isSubdomain(subdomain, domain) {
	const dot = subdomain.length - domain.length - 1;
	return dot > 0 && subdomain[dot] === "." && subdomain.endsWith(domain);
	}

	// Exports
	module.exports = wrap({ http: http, https: https });
	module.exports.wrap = wrap;