New source found from dndbeyond.com

2026-07-08 01:00:09 -07:00
parent 9a983a6d7b
commit dcefa0d2f2
2865 changed files with 222467 additions and 49053 deletions
@@ -0,0 +1,61 @@
+'use strict';
+
+import toFormData from './toFormData.js';
+
+/**
+ * It encodes a string by replacing all characters that are not in the unreserved set with
+ * their percent-encoded equivalents
+ *
+ * @param {string} str - The string to encode.
+ *
+ * @returns {string} The encoded string.
+ */
+function encode(str) {
+  const charMap = {
+    '!': '%21',
+    "'": '%27',
+    '(': '%28',
+    ')': '%29',
+    '~': '%7E',
+    '%20': '+',
+  };
+  return encodeURIComponent(str).replace(/[!'()~]|%20/g, function replacer(match) {
+    return charMap[match];
+  });
+}
+
+/**
+ * It takes a params object and converts it to a FormData object
+ *
+ * @param {Object<string, any>} params - The parameters to be converted to a FormData object.
+ * @param {Object<string, any>} options - The options object passed to the Axios constructor.
+ *
+ * @returns {void}
+ */
+function AxiosURLSearchParams(params, options) {
+  this._pairs = [];
+
+  params && toFormData(params, this, options);
+}
+
+const prototype = AxiosURLSearchParams.prototype;
+
+prototype.append = function append(name, value) {
+  this._pairs.push([name, value]);
+};
+
+prototype.toString = function toString(encoder) {
+  const _encode = encoder
+    ? function (value) {
+        return encoder.call(this, value, encode);
+      }
+    : encode;
+
+  return this._pairs
+    .map(function each(pair) {
+      return _encode(pair[0]) + '=' + _encode(pair[1]);
+    }, '')
+    .join('&');
+};
+
+export default AxiosURLSearchParams;
@@ -0,0 +1,77 @@
+const HttpStatusCode = {
+  Continue: 100,
+  SwitchingProtocols: 101,
+  Processing: 102,
+  EarlyHints: 103,
+  Ok: 200,
+  Created: 201,
+  Accepted: 202,
+  NonAuthoritativeInformation: 203,
+  NoContent: 204,
+  ResetContent: 205,
+  PartialContent: 206,
+  MultiStatus: 207,
+  AlreadyReported: 208,
+  ImUsed: 226,
+  MultipleChoices: 300,
+  MovedPermanently: 301,
+  Found: 302,
+  SeeOther: 303,
+  NotModified: 304,
+  UseProxy: 305,
+  Unused: 306,
+  TemporaryRedirect: 307,
+  PermanentRedirect: 308,
+  BadRequest: 400,
+  Unauthorized: 401,
+  PaymentRequired: 402,
+  Forbidden: 403,
+  NotFound: 404,
+  MethodNotAllowed: 405,
+  NotAcceptable: 406,
+  ProxyAuthenticationRequired: 407,
+  RequestTimeout: 408,
+  Conflict: 409,
+  Gone: 410,
+  LengthRequired: 411,
+  PreconditionFailed: 412,
+  PayloadTooLarge: 413,
+  UriTooLong: 414,
+  UnsupportedMediaType: 415,
+  RangeNotSatisfiable: 416,
+  ExpectationFailed: 417,
+  ImATeapot: 418,
+  MisdirectedRequest: 421,
+  UnprocessableEntity: 422,
+  Locked: 423,
+  FailedDependency: 424,
+  TooEarly: 425,
+  UpgradeRequired: 426,
+  PreconditionRequired: 428,
+  TooManyRequests: 429,
+  RequestHeaderFieldsTooLarge: 431,
+  UnavailableForLegalReasons: 451,
+  InternalServerError: 500,
+  NotImplemented: 501,
+  BadGateway: 502,
+  ServiceUnavailable: 503,
+  GatewayTimeout: 504,
+  HttpVersionNotSupported: 505,
+  VariantAlsoNegotiates: 506,
+  InsufficientStorage: 507,
+  LoopDetected: 508,
+  NotExtended: 510,
+  NetworkAuthenticationRequired: 511,
+  WebServerIsDown: 521,
+  ConnectionTimedOut: 522,
+  OriginIsUnreachable: 523,
+  TimeoutOccurred: 524,
+  SslHandshakeFailed: 525,
+  InvalidSslCertificate: 526,
+};
+
+Object.entries(HttpStatusCode).forEach(([key, value]) => {
+  HttpStatusCode[value] = key;
+});
+
+export default HttpStatusCode;
@@ -1,11 +1,14 @@
 'use strict';

-module.exports = function bind(fn, thisArg) {
+/**
+ * Create a bound version of a function with a specified `this` context
+ *
+ * @param {Function} fn - The function to bind
+ * @param {*} thisArg - The value to be passed as the `this` parameter
+ * @returns {Function} A new function that will call the original function with the specified `this` context
+ */
+export default function bind(fn, thisArg) {
  return function wrap() {
-    var args = new Array(arguments.length);
-    for (var i = 0; i < args.length; i++) {
-      args[i] = arguments[i];
-    }
-    return fn.apply(thisArg, args);
+    return fn.apply(thisArg, arguments);
  };
-};
+}
@@ -1,15 +1,22 @@
 'use strict';

-var utils = require('./../utils');
+import utils from '../utils.js';
+import AxiosURLSearchParams from './AxiosURLSearchParams.js';

-function encode(val) {
-  return encodeURIComponent(val).
-    replace(/%3A/gi, ':').
-    replace(/%24/g, '$').
-    replace(/%2C/gi, ',').
-    replace(/%20/g, '+').
-    replace(/%5B/gi, '[').
-    replace(/%5D/gi, ']');
+/**
+ * It replaces URL-encoded forms of `:`, `$`, `,`, and spaces with
+ * their plain counterparts (`:`, `$`, `,`, `+`).
+ *
+ * @param {string} val The value to be encoded.
+ *
+ * @returns {string} The encoded value.
+ */
+export function encode(val) {
+  return encodeURIComponent(val)
+    .replace(/%3A/gi, ':')
+    .replace(/%24/g, '$')
+    .replace(/%2C/gi, ',')
+    .replace(/%20/g, '+');
 }

 /**
@@ -17,54 +24,43 @@ function encode(val) {
 *
 * @param {string} url The base of the url (e.g., http://www.google.com)
 * @param {object} [params] The params to be appended
+ * @param {?(object|Function)} options
+ *
 * @returns {string} The formatted url
 */
-module.exports = function buildURL(url, params, paramsSerializer) {
-  /*eslint no-param-reassign:0*/
+export default function buildURL(url, params, options) {
  if (!params) {
    return url;
  }

-  var serializedParams;
-  if (paramsSerializer) {
-    serializedParams = paramsSerializer(params);
-  } else if (utils.isURLSearchParams(params)) {
-    serializedParams = params.toString();
+  const _encode = (options && options.encode) || encode;
+
+  const _options = utils.isFunction(options)
+    ? {
+        serialize: options,
+      }
+    : options;
+
+  const serializeFn = _options && _options.serialize;
+
+  let serializedParams;
+
+  if (serializeFn) {
+    serializedParams = serializeFn(params, _options);
  } else {
-    var parts = [];
-
-    utils.forEach(params, function serialize(val, key) {
-      if (val === null || typeof val === 'undefined') {
-        return;
-      }
-
-      if (utils.isArray(val)) {
-        key = key + '[]';
-      } else {
-        val = [val];
-      }
-
-      utils.forEach(val, function parseValue(v) {
-        if (utils.isDate(v)) {
-          v = v.toISOString();
-        } else if (utils.isObject(v)) {
-          v = JSON.stringify(v);
-        }
-        parts.push(encode(key) + '=' + encode(v));
-      });
-    });
-
-    serializedParams = parts.join('&');
+    serializedParams = utils.isURLSearchParams(params)
+      ? params.toString()
+      : new AxiosURLSearchParams(params, _options).toString(_encode);
  }

  if (serializedParams) {
-    var hashmarkIndex = url.indexOf('#');
+    const hashmarkIndex = url.indexOf('#');
+
    if (hashmarkIndex !== -1) {
      url = url.slice(0, hashmarkIndex);
    }
-
    url += (url.indexOf('?') === -1 ? '?' : '&') + serializedParams;
  }

  return url;
-};
+}
@@ -5,10 +5,11 @@
 *
 * @param {string} baseURL The base URL
 * @param {string} relativeURL The relative URL
+ *
 * @returns {string} The combined URL
 */
-module.exports = function combineURLs(baseURL, relativeURL) {
+export default function combineURLs(baseURL, relativeURL) {
  return relativeURL
-    ? baseURL.replace(/\/+$/, '') + '/' + relativeURL.replace(/^\/+/, '')
+    ? baseURL.replace(/\/?\/$/, '') + '/' + relativeURL.replace(/^\/+/, '')
    : baseURL;
-};
+}
@@ -0,0 +1,57 @@
+import CanceledError from '../cancel/CanceledError.js';
+import AxiosError from '../core/AxiosError.js';
+import utils from '../utils.js';
+
+const composeSignals = (signals, timeout) => {
+  signals = signals ? signals.filter(Boolean) : [];
+
+  if (!timeout && !signals.length) {
+    return;
+  }
+
+  const controller = new AbortController();
+
+  let aborted = false;
+
+  const onabort = function (reason) {
+    if (!aborted) {
+      aborted = true;
+      unsubscribe();
+      const err = reason instanceof Error ? reason : this.reason;
+      controller.abort(
+        err instanceof AxiosError
+          ? err
+          : new CanceledError(err instanceof Error ? err.message : err)
+      );
+    }
+  };
+
+  let timer =
+    timeout &&
+    setTimeout(() => {
+      timer = null;
+      onabort(new AxiosError(`timeout of ${timeout}ms exceeded`, AxiosError.ETIMEDOUT));
+    }, timeout);
+
+  const unsubscribe = () => {
+    if (!signals) { return; }
+    timer && clearTimeout(timer);
+    timer = null;
+    signals.forEach((signal) => {
+      signal.unsubscribe
+        ? signal.unsubscribe(onabort)
+        : signal.removeEventListener('abort', onabort);
+    });
+    signals = null;
+  };
+
+  signals.forEach((signal) => signal.addEventListener('abort', onabort));
+
+  const { signal } = controller;
+
+  signal.unsubscribe = () => utils.asap(unsubscribe);
+
+  return signal;
+};
+
+export default composeSignals;
@@ -1,53 +1,60 @@
-'use strict';
+import utils from '../utils.js';
+import platform from '../platform/index.js';

-var utils = require('./../utils');
+export default platform.hasStandardBrowserEnv
+  ? // Standard browser envs support document.cookie
+    {
+      write(name, value, expires, path, domain, secure, sameSite) {
+        if (typeof document === 'undefined') return;

-module.exports = (
-  utils.isStandardBrowserEnv() ?
+        const cookie = [`${name}=${encodeURIComponent(value)}`];

-  // Standard browser envs support document.cookie
-    (function standardBrowserEnv() {
-      return {
-        write: function write(name, value, expires, path, domain, secure) {
-          var cookie = [];
-          cookie.push(name + '=' + encodeURIComponent(value));
-
-          if (utils.isNumber(expires)) {
-            cookie.push('expires=' + new Date(expires).toGMTString());
-          }
-
-          if (utils.isString(path)) {
-            cookie.push('path=' + path);
-          }
-
-          if (utils.isString(domain)) {
-            cookie.push('domain=' + domain);
-          }
-
-          if (secure === true) {
-            cookie.push('secure');
-          }
-
-          document.cookie = cookie.join('; ');
-        },
-
-        read: function read(name) {
-          var match = document.cookie.match(new RegExp('(^|;\\s*)(' + name + ')=([^;]*)'));
-          return (match ? decodeURIComponent(match[3]) : null);
-        },
-
-        remove: function remove(name) {
-          this.write(name, '', Date.now() - 86400000);
+        if (utils.isNumber(expires)) {
+          cookie.push(`expires=${new Date(expires).toUTCString()}`);
+        }
+        if (utils.isString(path)) {
+          cookie.push(`path=${path}`);
+        }
+        if (utils.isString(domain)) {
+          cookie.push(`domain=${domain}`);
+        }
+        if (secure === true) {
+          cookie.push('secure');
+        }
+        if (utils.isString(sameSite)) {
+          cookie.push(`SameSite=${sameSite}`);
        }
-      };
-    })() :

-  // Non standard browser env (web workers, react-native) lack needed support.
-    (function nonStandardBrowserEnv() {
-      return {
-        write: function write() {},
-        read: function read() { return null; },
-        remove: function remove() {}
-      };
-    })()
-);
+        document.cookie = cookie.join('; ');
+      },
+
+      read(name) {
+        if (typeof document === 'undefined') return null;
+        // Match name=value by splitting on the semicolon separator instead of building a
+        // RegExp from `name` — interpolating an unescaped string into a RegExp would let
+        // metacharacters (e.g. `.+?` in an attacker-influenced cookie name) cause ReDoS or
+        // match the wrong cookie. Browsers may serialize cookie pairs as either ";" or
+        // "; ", so ignore optional whitespace before each cookie name.
+        const cookies = document.cookie.split(';');
+        for (let i = 0; i < cookies.length; i++) {
+          const cookie = cookies[i].replace(/^\s+/, '');
+          const eq = cookie.indexOf('=');
+          if (eq !== -1 && cookie.slice(0, eq) === name) {
+            return decodeURIComponent(cookie.slice(eq + 1));
+          }
+        }
+        return null;
+      },
+
+      remove(name) {
+        this.write(name, '', Date.now() - 86400000, '/');
+      },
+    }
+  : // Non-standard browser env (web workers, react-native) lack needed support.
+    {
+      write() {},
+      read() {
+        return null;
+      },
+      remove() {},
+    };
@@ -0,0 +1,100 @@
+/**
+ * Estimate decoded byte length of a data:// URL *without* allocating large buffers.
+ * - For base64: compute exact decoded size using length and padding;
+ *               handle %XX at the character-count level (no string allocation).
+ * - For non-base64: use UTF-8 byteLength of the encoded body as a safe upper bound.
+ *
+ * @param {string} url
+ * @returns {number}
+ */
+export default function estimateDataURLDecodedBytes(url) {
+  if (!url || typeof url !== 'string') return 0;
+  if (!url.startsWith('data:')) return 0;
+
+  const comma = url.indexOf(',');
+  if (comma < 0) return 0;
+
+  const meta = url.slice(5, comma);
+  const body = url.slice(comma + 1);
+  const isBase64 = /;base64/i.test(meta);
+
+  if (isBase64) {
+    let effectiveLen = body.length;
+    const len = body.length; // cache length
+
+    for (let i = 0; i < len; i++) {
+      if (body.charCodeAt(i) === 37 /* '%' */ && i + 2 < len) {
+        const a = body.charCodeAt(i + 1);
+        const b = body.charCodeAt(i + 2);
+        const isHex =
+          ((a >= 48 && a <= 57) || (a >= 65 && a <= 70) || (a >= 97 && a <= 102)) &&
+          ((b >= 48 && b <= 57) || (b >= 65 && b <= 70) || (b >= 97 && b <= 102));
+
+        if (isHex) {
+          effectiveLen -= 2;
+          i += 2;
+        }
+      }
+    }
+
+    let pad = 0;
+    let idx = len - 1;
+
+    const tailIsPct3D = (j) =>
+      j >= 2 &&
+      body.charCodeAt(j - 2) === 37 && // '%'
+      body.charCodeAt(j - 1) === 51 && // '3'
+      (body.charCodeAt(j) === 68 || body.charCodeAt(j) === 100); // 'D' or 'd'
+
+    if (idx >= 0) {
+      if (body.charCodeAt(idx) === 61 /* '=' */) {
+        pad++;
+        idx--;
+      } else if (tailIsPct3D(idx)) {
+        pad++;
+        idx -= 3;
+      }
+    }
+
+    if (pad === 1 && idx >= 0) {
+      if (body.charCodeAt(idx) === 61 /* '=' */) {
+        pad++;
+      } else if (tailIsPct3D(idx)) {
+        pad++;
+      }
+    }
+
+    const groups = Math.floor(effectiveLen / 4);
+    const bytes = groups * 3 - (pad || 0);
+    return bytes > 0 ? bytes : 0;
+  }
+
+  if (typeof Buffer !== 'undefined' && typeof Buffer.byteLength === 'function') {
+    return Buffer.byteLength(body, 'utf8');
+  }
+
+  // Compute UTF-8 byte length directly from UTF-16 code units without allocating
+  // a byte buffer (TextEncoder.encode would defeat the DoS guard on large bodies).
+  // Using body.length here would undercount non-ASCII (e.g. '€' is 1 code unit
+  // but 3 UTF-8 bytes).
+  let bytes = 0;
+  for (let i = 0, len = body.length; i < len; i++) {
+    const c = body.charCodeAt(i);
+    if (c < 0x80) {
+      bytes += 1;
+    } else if (c < 0x800) {
+      bytes += 2;
+    } else if (c >= 0xd800 && c <= 0xdbff && i + 1 < len) {
+      const next = body.charCodeAt(i + 1);
+      if (next >= 0xdc00 && next <= 0xdfff) {
+        bytes += 4;
+        i++;
+      } else {
+        bytes += 3;
+      }
+    } else {
+      bytes += 3;
+    }
+  }
+  return bytes;
+}
@@ -0,0 +1,97 @@
+'use strict';
+
+import utils from '../utils.js';
+
+/**
+ * It takes a string like `foo[x][y][z]` and returns an array like `['foo', 'x', 'y', 'z']
+ *
+ * @param {string} name - The name of the property to get.
+ *
+ * @returns An array of strings.
+ */
+function parsePropPath(name) {
+  // foo[x][y][z]
+  // foo.x.y.z
+  // foo-x-y-z
+  // foo x y z
+  return utils.matchAll(/\w+|\[(\w*)]/g, name).map((match) => {
+    return match[0] === '[]' ? '' : match[1] || match[0];
+  });
+}
+
+/**
+ * Convert an array to an object.
+ *
+ * @param {Array<any>} arr - The array to convert to an object.
+ *
+ * @returns An object with the same keys and values as the array.
+ */
+function arrayToObject(arr) {
+  const obj = {};
+  const keys = Object.keys(arr);
+  let i;
+  const len = keys.length;
+  let key;
+  for (i = 0; i < len; i++) {
+    key = keys[i];
+    obj[key] = arr[key];
+  }
+  return obj;
+}
+
+/**
+ * It takes a FormData object and returns a JavaScript object
+ *
+ * @param {string} formData The FormData object to convert to JSON.
+ *
+ * @returns {Object<string, any> | null} The converted object.
+ */
+function formDataToJSON(formData) {
+  function buildPath(path, value, target, index) {
+    let name = path[index++];
+
+    if (name === '__proto__') return true;
+
+    const isNumericKey = Number.isFinite(+name);
+    const isLast = index >= path.length;
+    name = !name && utils.isArray(target) ? target.length : name;
+
+    if (isLast) {
+      if (utils.hasOwnProp(target, name)) {
+        target[name] = utils.isArray(target[name])
+          ? target[name].concat(value)
+          : [target[name], value];
+      } else {
+        target[name] = value;
+      }
+
+      return !isNumericKey;
+    }
+
+    if (!utils.hasOwnProp(target, name) || !utils.isObject(target[name])) {
+      target[name] = [];
+    }
+
+    const result = buildPath(path, value, target[name], index);
+
+    if (result && utils.isArray(target[name])) {
+      target[name] = arrayToObject(target[name]);
+    }
+
+    return !isNumericKey;
+  }
+
+  if (utils.isFormData(formData) && utils.isFunction(formData.entries)) {
+    const obj = {};
+
+    utils.forEachEntry(formData, (name, value) => {
+      buildPath(parsePropPath(name), value, obj, 0);
+    });
+
+    return obj;
+  }
+
+  return null;
+}
+
+export default formDataToJSON;
@@ -4,11 +4,16 @@
 * Determines whether the specified URL is absolute
 *
 * @param {string} url The URL to test
+ *
 * @returns {boolean} True if the specified URL is absolute, otherwise false
 */
-module.exports = function isAbsoluteURL(url) {
+export default function isAbsoluteURL(url) {
  // A URL is considered absolute if it begins with "<scheme>://" or "//" (protocol-relative URL).
  // RFC 3986 defines scheme name as a sequence of characters beginning with a letter and followed
  // by any combination of letters, digits, plus, period, or hyphen.
+  if (typeof url !== 'string') {
+    return false;
+  }
+
  return /^([a-z][a-z\d+\-.]*:)?\/\//i.test(url);
-};
+}
@@ -1,13 +1,14 @@
 'use strict';

-var utils = require('./../utils');
+import utils from '../utils.js';

 /**
 * Determines whether the payload is an error thrown by Axios
 *
 * @param {*} payload The value to test
+ *
 * @returns {boolean} True if the payload is an error thrown by Axios, otherwise false
 */
-module.exports = function isAxiosError(payload) {
-  return utils.isObject(payload) && (payload.isAxiosError === true);
-};
+export default function isAxiosError(payload) {
+  return utils.isObject(payload) && payload.isAxiosError === true;
+}
@@ -1,68 +1,16 @@
-'use strict';
+import platform from '../platform/index.js';

-var utils = require('./../utils');
+export default platform.hasStandardBrowserEnv
+  ? ((origin, isMSIE) => (url) => {
+      url = new URL(url, platform.origin);

-module.exports = (
-  utils.isStandardBrowserEnv() ?
-
-  // Standard browser envs have full support of the APIs needed to test
-  // whether the request URL is of the same origin as current location.
-    (function standardBrowserEnv() {
-      var msie = /(msie|trident)/i.test(navigator.userAgent);
-      var urlParsingNode = document.createElement('a');
-      var originURL;
-
-      /**
-    * Parse a URL to discover it's components
-    *
-    * @param {String} url The URL to be parsed
-    * @returns {Object}
-    */
-      function resolveURL(url) {
-        var href = url;
-
-        if (msie) {
-        // IE needs attribute set twice to normalize properties
-          urlParsingNode.setAttribute('href', href);
-          href = urlParsingNode.href;
-        }
-
-        urlParsingNode.setAttribute('href', href);
-
-        // urlParsingNode provides the UrlUtils interface - http://url.spec.whatwg.org/#urlutils
-        return {
-          href: urlParsingNode.href,
-          protocol: urlParsingNode.protocol ? urlParsingNode.protocol.replace(/:$/, '') : '',
-          host: urlParsingNode.host,
-          search: urlParsingNode.search ? urlParsingNode.search.replace(/^\?/, '') : '',
-          hash: urlParsingNode.hash ? urlParsingNode.hash.replace(/^#/, '') : '',
-          hostname: urlParsingNode.hostname,
-          port: urlParsingNode.port,
-          pathname: (urlParsingNode.pathname.charAt(0) === '/') ?
-            urlParsingNode.pathname :
-            '/' + urlParsingNode.pathname
-        };
-      }
-
-      originURL = resolveURL(window.location.href);
-
-      /**
-    * Determine if a URL shares the same origin as the current location
-    *
-    * @param {String} requestURL The URL to test
-    * @returns {boolean} True if URL shares the same origin, otherwise false
-    */
-      return function isURLSameOrigin(requestURL) {
-        var parsed = (utils.isString(requestURL)) ? resolveURL(requestURL) : requestURL;
-        return (parsed.protocol === originURL.protocol &&
-            parsed.host === originURL.host);
-      };
-    })() :
-
-  // Non standard browser envs (web workers, react-native) lack needed support.
-    (function nonStandardBrowserEnv() {
-      return function isURLSameOrigin() {
-        return true;
-      };
-    })()
-);
+      return (
+        origin.protocol === url.protocol &&
+        origin.host === url.host &&
+        (isMSIE || origin.port === url.port)
+      );
+    })(
+      new URL(platform.origin),
+      platform.navigator && /(msie|trident)/i.test(platform.navigator.userAgent)
+    )
+  : () => true;
@@ -1,12 +0,0 @@
-'use strict';
-
-var utils = require('../utils');
-
-module.exports = function normalizeHeaderName(headers, normalizedName) {
-  utils.forEach(headers, function processHeader(value, name) {
-    if (name !== normalizedName && name.toUpperCase() === normalizedName.toUpperCase()) {
-      headers[normalizedName] = value;
-      delete headers[name];
-    }
-  });
-};
@@ -0,0 +1,2 @@
+// eslint-disable-next-line strict
+export default null;
@@ -1,15 +1,28 @@
 'use strict';

-var utils = require('./../utils');
+import utils from '../utils.js';

-// Headers whose duplicates are ignored by node
+// RawAxiosHeaders whose duplicates are ignored by node
 // c.f. https://nodejs.org/api/http.html#http_message_headers
-var ignoreDuplicateOf = [
-  'age', 'authorization', 'content-length', 'content-type', 'etag',
-  'expires', 'from', 'host', 'if-modified-since', 'if-unmodified-since',
-  'last-modified', 'location', 'max-forwards', 'proxy-authorization',
-  'referer', 'retry-after', 'user-agent'
-];
+const ignoreDuplicateOf = utils.toObjectSet([
+  'age',
+  'authorization',
+  'content-length',
+  'content-type',
+  'etag',
+  'expires',
+  'from',
+  'host',
+  'if-modified-since',
+  'if-unmodified-since',
+  'last-modified',
+  'location',
+  'max-forwards',
+  'proxy-authorization',
+  'referer',
+  'retry-after',
+  'user-agent',
+]);

 /**
 * Parse headers into an object
@@ -21,33 +34,36 @@ var ignoreDuplicateOf = [
 * Transfer-Encoding: chunked
 * ```
 *
- * @param {String} headers Headers needing to be parsed
+ * @param {String} rawHeaders Headers needing to be parsed
+ *
 * @returns {Object} Headers parsed into an object
 */
-module.exports = function parseHeaders(headers) {
-  var parsed = {};
-  var key;
-  var val;
-  var i;
+export default (rawHeaders) => {
+  const parsed = {};
+  let key;
+  let val;
+  let i;

-  if (!headers) { return parsed; }
+  rawHeaders &&
+    rawHeaders.split('\n').forEach(function parser(line) {
+      i = line.indexOf(':');
+      key = line.substring(0, i).trim().toLowerCase();
+      val = line.substring(i + 1).trim();

-  utils.forEach(headers.split('\n'), function parser(line) {
-    i = line.indexOf(':');
-    key = utils.trim(line.substr(0, i)).toLowerCase();
-    val = utils.trim(line.substr(i + 1));
-
-    if (key) {
-      if (parsed[key] && ignoreDuplicateOf.indexOf(key) >= 0) {
+      if (!key || (parsed[key] && ignoreDuplicateOf[key])) {
        return;
      }
+
      if (key === 'set-cookie') {
-        parsed[key] = (parsed[key] ? parsed[key] : []).concat([val]);
+        if (parsed[key]) {
+          parsed[key].push(val);
+        } else {
+          parsed[key] = [val];
+        }
      } else {
        parsed[key] = parsed[key] ? parsed[key] + ', ' + val : val;
      }
-    }
-  });
+    });

  return parsed;
 };
@@ -0,0 +1,6 @@
+'use strict';
+
+export default function parseProtocol(url) {
+  const match = /^([-+\w]{1,25}):(?:\/\/)?/.exec(url);
+  return (match && match[1]) || '';
+}
@@ -0,0 +1,54 @@
+import speedometer from './speedometer.js';
+import throttle from './throttle.js';
+import utils from '../utils.js';
+
+export const progressEventReducer = (listener, isDownloadStream, freq = 3) => {
+  let bytesNotified = 0;
+  const _speedometer = speedometer(50, 250);
+
+  return throttle((e) => {
+    if (!e || typeof e.loaded !== 'number') {
+      return;
+    }
+    const rawLoaded = e.loaded;
+    const total = e.lengthComputable ? e.total : undefined;
+    const loaded = total != null ? Math.min(rawLoaded, total) : rawLoaded;
+    const progressBytes = Math.max(0, loaded - bytesNotified);
+    const rate = _speedometer(progressBytes);
+
+    bytesNotified = Math.max(bytesNotified, loaded);
+
+    const data = {
+      loaded,
+      total,
+      progress: total ? loaded / total : undefined,
+      bytes: progressBytes,
+      rate: rate ? rate : undefined,
+      estimated: rate && total ? (total - loaded) / rate : undefined,
+      event: e,
+      lengthComputable: total != null,
+      [isDownloadStream ? 'download' : 'upload']: true,
+    };
+
+    listener(data);
+  }, freq);
+};
+
+export const progressEventDecorator = (total, throttled) => {
+  const lengthComputable = total != null;
+
+  return [
+    (loaded) =>
+      throttled[0]({
+        lengthComputable,
+        total,
+        loaded,
+      }),
+    throttled[1],
+  ];
+};
+
+export const asyncDecorator =
+  (fn) =>
+  (...args) =>
+    utils.asap(() => fn(...args));
@@ -0,0 +1,112 @@
+import platform from '../platform/index.js';
+import utils from '../utils.js';
+import isURLSameOrigin from './isURLSameOrigin.js';
+import cookies from './cookies.js';
+import buildFullPath from '../core/buildFullPath.js';
+import mergeConfig from '../core/mergeConfig.js';
+import AxiosHeaders from '../core/AxiosHeaders.js';
+import buildURL from './buildURL.js';
+
+const FORM_DATA_CONTENT_HEADERS = ['content-type', 'content-length'];
+
+function setFormDataHeaders(headers, formHeaders, policy) {
+  if (policy !== 'content-only') {
+    headers.set(formHeaders);
+    return;
+  }
+
+  Object.entries(formHeaders).forEach(([key, val]) => {
+    if (FORM_DATA_CONTENT_HEADERS.includes(key.toLowerCase())) {
+      headers.set(key, val);
+    }
+  });
+}
+
+/**
+ * Encode a UTF-8 string to a Latin-1 byte string for use with btoa().
+ * This is a modern replacement for the deprecated unescape(encodeURIComponent(str)) pattern.
+ *
+ * @param {string} str The string to encode
+ *
+ * @returns {string} UTF-8 bytes as a Latin-1 string
+ */
+const encodeUTF8 = (str) =>
+  encodeURIComponent(str).replace(/%([0-9A-F]{2})/gi, (_, hex) =>
+    String.fromCharCode(parseInt(hex, 16))
+  );
+
+function resolveConfig(config) {
+  const newConfig = mergeConfig({}, config);
+
+  // Read only own properties to prevent prototype pollution gadgets
+  // (e.g. Object.prototype.baseURL = 'https://evil.com').
+  const own = (key) => (utils.hasOwnProp(newConfig, key) ? newConfig[key] : undefined);
+
+  const data = own('data');
+  let withXSRFToken = own('withXSRFToken');
+  const xsrfHeaderName = own('xsrfHeaderName');
+  const xsrfCookieName = own('xsrfCookieName');
+  let headers = own('headers');
+  const auth = own('auth');
+  const baseURL = own('baseURL');
+  const allowAbsoluteUrls = own('allowAbsoluteUrls');
+  const url = own('url');
+
+  newConfig.headers = headers = AxiosHeaders.from(headers);
+
+  newConfig.url = buildURL(
+    buildFullPath(baseURL, url, allowAbsoluteUrls),
+    own('params'),
+    own('paramsSerializer')
+  );
+
+  // HTTP basic authentication
+  if (auth) {
+    headers.set(
+      'Authorization',
+      'Basic ' +
+        btoa((auth.username || '') + ':' + (auth.password ? encodeUTF8(auth.password) : ''))
+    );
+  }
+
+  if (utils.isFormData(data)) {
+    if (
+      platform.hasStandardBrowserEnv ||
+      platform.hasStandardBrowserWebWorkerEnv ||
+      utils.isReactNative(data)
+    ) {
+      headers.setContentType(undefined); // browser/web worker/RN handles it
+    } else if (utils.isFunction(data.getHeaders)) {
+      // Node.js FormData (like form-data package)
+      setFormDataHeaders(headers, data.getHeaders(), own('formDataHeaderPolicy'));
+    }
+  }
+
+  // Add xsrf header
+  // This is only done if running in a standard browser environment.
+  // Specifically not if we're in a web worker, or react-native.
+
+  if (platform.hasStandardBrowserEnv) {
+    if (utils.isFunction(withXSRFToken)) {
+      withXSRFToken = withXSRFToken(newConfig);
+    }
+
+    // Strict boolean check — prevents proto-pollution gadgets (e.g. Object.prototype.withXSRFToken = 1)
+    // and misconfigurations (e.g. "false") from short-circuiting the same-origin check and leaking
+    // the XSRF token cross-origin.
+    const shouldSendXSRF =
+      withXSRFToken === true || (withXSRFToken == null && isURLSameOrigin(newConfig.url));
+
+    if (shouldSendXSRF) {
+      const xsrfValue = xsrfHeaderName && xsrfCookieName && cookies.read(xsrfCookieName);
+
+      if (xsrfValue) {
+        headers.set(xsrfHeaderName, xsrfValue);
+      }
+    }
+  }
+
+  return newConfig;
+}
+
+export default resolveConfig;
@@ -0,0 +1,60 @@
+'use strict';
+
+import utils from '../utils.js';
+
+function trimSPorHTAB(str) {
+  let start = 0;
+  let end = str.length;
+
+  while (start < end) {
+    const code = str.charCodeAt(start);
+
+    if (code !== 0x09 && code !== 0x20) {
+      break;
+    }
+
+    start += 1;
+  }
+
+  while (end > start) {
+    const code = str.charCodeAt(end - 1);
+
+    if (code !== 0x09 && code !== 0x20) {
+      break;
+    }
+
+    end -= 1;
+  }
+
+  return start === 0 && end === str.length ? str : str.slice(start, end);
+}
+
+// The control-code ranges are intentional: header sanitization strips C0/DEL bytes.
+// eslint-disable-next-line no-control-regex
+const INVALID_UNICODE_HEADER_VALUE_CHARS = new RegExp('[\\u0000-\\u0008\\u000a-\\u001f\\u007f]+', 'g');
+// eslint-disable-next-line no-control-regex
+const INVALID_BYTE_STRING_HEADER_VALUE_CHARS = new RegExp('[^\\u0009\\u0020-\\u007e\\u0080-\\u00ff]+', 'g');
+
+function sanitizeValue(value, invalidChars) {
+  if (utils.isArray(value)) {
+    return value.map((item) => sanitizeValue(item, invalidChars));
+  }
+
+  return trimSPorHTAB(String(value).replace(invalidChars, ''));
+}
+
+export const sanitizeHeaderValue = (value) =>
+  sanitizeValue(value, INVALID_UNICODE_HEADER_VALUE_CHARS);
+
+export const sanitizeByteStringHeaderValue = (value) =>
+  sanitizeValue(value, INVALID_BYTE_STRING_HEADER_VALUE_CHARS);
+
+export function toByteStringHeaderObject(headers) {
+  const byteStringHeaders = Object.create(null);
+
+  utils.forEach(headers.toJSON(), (value, header) => {
+    byteStringHeaders[header] = sanitizeByteStringHeaderValue(value);
+  });
+
+  return byteStringHeaders;
+}
@@ -0,0 +1,55 @@
+'use strict';
+
+/**
+ * Calculate data maxRate
+ * @param {Number} [samplesCount= 10]
+ * @param {Number} [min= 1000]
+ * @returns {Function}
+ */
+function speedometer(samplesCount, min) {
+  samplesCount = samplesCount || 10;
+  const bytes = new Array(samplesCount);
+  const timestamps = new Array(samplesCount);
+  let head = 0;
+  let tail = 0;
+  let firstSampleTS;
+
+  min = min !== undefined ? min : 1000;
+
+  return function push(chunkLength) {
+    const now = Date.now();
+
+    const startedAt = timestamps[tail];
+
+    if (!firstSampleTS) {
+      firstSampleTS = now;
+    }
+
+    bytes[head] = chunkLength;
+    timestamps[head] = now;
+
+    let i = tail;
+    let bytesCount = 0;
+
+    while (i !== head) {
+      bytesCount += bytes[i++];
+      i = i % samplesCount;
+    }
+
+    head = (head + 1) % samplesCount;
+
+    if (head === tail) {
+      tail = (tail + 1) % samplesCount;
+    }
+
+    if (now - firstSampleTS < min) {
+      return;
+    }
+
+    const passed = startedAt && now - startedAt;
+
+    return passed ? Math.round((bytesCount * 1000) / passed) : undefined;
+  };
+}
+
+export default speedometer;
@@ -7,7 +7,7 @@
 *
 *  ```js
 *  function f(x, y, z) {}
- *  var args = [1, 2, 3];
+ *  const args = [1, 2, 3];
 *  f.apply(null, args);
 *  ```
 *
@@ -18,10 +18,11 @@
 *  ```
 *
 * @param {Function} callback
+ *
 * @returns {Function}
 */
-module.exports = function spread(callback) {
+export default function spread(callback) {
  return function wrap(arr) {
    return callback.apply(null, arr);
  };
-};
+}
@@ -0,0 +1,44 @@
+/**
+ * Throttle decorator
+ * @param {Function} fn
+ * @param {Number} freq
+ * @return {Function}
+ */
+function throttle(fn, freq) {
+  let timestamp = 0;
+  let threshold = 1000 / freq;
+  let lastArgs;
+  let timer;
+
+  const invoke = (args, now = Date.now()) => {
+    timestamp = now;
+    lastArgs = null;
+    if (timer) {
+      clearTimeout(timer);
+      timer = null;
+    }
+    fn(...args);
+  };
+
+  const throttled = (...args) => {
+    const now = Date.now();
+    const passed = now - timestamp;
+    if (passed >= threshold) {
+      invoke(args, now);
+    } else {
+      lastArgs = args;
+      if (!timer) {
+        timer = setTimeout(() => {
+          timer = null;
+          invoke(lastArgs);
+        }, threshold - passed);
+      }
+    }
+  };
+
+  const flush = () => lastArgs && invoke(lastArgs);
+
+  return [throttled, flush];
+}
+
+export default throttle;
@@ -0,0 +1,249 @@
+'use strict';
+
+import utils from '../utils.js';
+import AxiosError from '../core/AxiosError.js';
+// temporary hotfix to avoid circular references until AxiosURLSearchParams is refactored
+import PlatformFormData from '../platform/node/classes/FormData.js';
+
+/**
+ * Determines if the given thing is a array or js object.
+ *
+ * @param {string} thing - The object or array to be visited.
+ *
+ * @returns {boolean}
+ */
+function isVisitable(thing) {
+  return utils.isPlainObject(thing) || utils.isArray(thing);
+}
+
+/**
+ * It removes the brackets from the end of a string
+ *
+ * @param {string} key - The key of the parameter.
+ *
+ * @returns {string} the key without the brackets.
+ */
+function removeBrackets(key) {
+  return utils.endsWith(key, '[]') ? key.slice(0, -2) : key;
+}
+
+/**
+ * It takes a path, a key, and a boolean, and returns a string
+ *
+ * @param {string} path - The path to the current key.
+ * @param {string} key - The key of the current object being iterated over.
+ * @param {string} dots - If true, the key will be rendered with dots instead of brackets.
+ *
+ * @returns {string} The path to the current key.
+ */
+function renderKey(path, key, dots) {
+  if (!path) return key;
+  return path
+    .concat(key)
+    .map(function each(token, i) {
+      // eslint-disable-next-line no-param-reassign
+      token = removeBrackets(token);
+      return !dots && i ? '[' + token + ']' : token;
+    })
+    .join(dots ? '.' : '');
+}
+
+/**
+ * If the array is an array and none of its elements are visitable, then it's a flat array.
+ *
+ * @param {Array<any>} arr - The array to check
+ *
+ * @returns {boolean}
+ */
+function isFlatArray(arr) {
+  return utils.isArray(arr) && !arr.some(isVisitable);
+}
+
+const predicates = utils.toFlatObject(utils, {}, null, function filter(prop) {
+  return /^is[A-Z]/.test(prop);
+});
+
+/**
+ * Convert a data object to FormData
+ *
+ * @param {Object} obj
+ * @param {?Object} [formData]
+ * @param {?Object} [options]
+ * @param {Function} [options.visitor]
+ * @param {Boolean} [options.metaTokens = true]
+ * @param {Boolean} [options.dots = false]
+ * @param {?Boolean} [options.indexes = false]
+ *
+ * @returns {Object}
+ **/
+
+/**
+ * It converts an object into a FormData object
+ *
+ * @param {Object<any, any>} obj - The object to convert to form data.
+ * @param {string} formData - The FormData object to append to.
+ * @param {Object<string, any>} options
+ *
+ * @returns
+ */
+function toFormData(obj, formData, options) {
+  if (!utils.isObject(obj)) {
+    throw new TypeError('target must be an object');
+  }
+
+  // eslint-disable-next-line no-param-reassign
+  formData = formData || new (PlatformFormData || FormData)();
+
+  // eslint-disable-next-line no-param-reassign
+  options = utils.toFlatObject(
+    options,
+    {
+      metaTokens: true,
+      dots: false,
+      indexes: false,
+    },
+    false,
+    function defined(option, source) {
+      // eslint-disable-next-line no-eq-null,eqeqeq
+      return !utils.isUndefined(source[option]);
+    }
+  );
+
+  const metaTokens = options.metaTokens;
+  // eslint-disable-next-line no-use-before-define
+  const visitor = options.visitor || defaultVisitor;
+  const dots = options.dots;
+  const indexes = options.indexes;
+  const _Blob = options.Blob || (typeof Blob !== 'undefined' && Blob);
+  const maxDepth = options.maxDepth === undefined ? 100 : options.maxDepth;
+  const useBlob = _Blob && utils.isSpecCompliantForm(formData);
+
+  if (!utils.isFunction(visitor)) {
+    throw new TypeError('visitor must be a function');
+  }
+
+  function convertValue(value) {
+    if (value === null) return '';
+
+    if (utils.isDate(value)) {
+      return value.toISOString();
+    }
+
+    if (utils.isBoolean(value)) {
+      return value.toString();
+    }
+
+    if (!useBlob && utils.isBlob(value)) {
+      throw new AxiosError('Blob is not supported. Use a Buffer instead.');
+    }
+
+    if (utils.isArrayBuffer(value) || utils.isTypedArray(value)) {
+      return useBlob && typeof Blob === 'function' ? new Blob([value]) : Buffer.from(value);
+    }
+
+    return value;
+  }
+
+  /**
+   * Default visitor.
+   *
+   * @param {*} value
+   * @param {String|Number} key
+   * @param {Array<String|Number>} path
+   * @this {FormData}
+   *
+   * @returns {boolean} return true to visit the each prop of the value recursively
+   */
+  function defaultVisitor(value, key, path) {
+    let arr = value;
+
+    if (utils.isReactNative(formData) && utils.isReactNativeBlob(value)) {
+      formData.append(renderKey(path, key, dots), convertValue(value));
+      return false;
+    }
+
+    if (value && !path && typeof value === 'object') {
+      if (utils.endsWith(key, '{}')) {
+        // eslint-disable-next-line no-param-reassign
+        key = metaTokens ? key : key.slice(0, -2);
+        // eslint-disable-next-line no-param-reassign
+        value = JSON.stringify(value);
+      } else if (
+        (utils.isArray(value) && isFlatArray(value)) ||
+        ((utils.isFileList(value) || utils.endsWith(key, '[]')) && (arr = utils.toArray(value)))
+      ) {
+        // eslint-disable-next-line no-param-reassign
+        key = removeBrackets(key);
+
+        arr.forEach(function each(el, index) {
+          !(utils.isUndefined(el) || el === null) &&
+            formData.append(
+              // eslint-disable-next-line no-nested-ternary
+              indexes === true
+                ? renderKey([key], index, dots)
+                : indexes === null
+                  ? key
+                  : key + '[]',
+              convertValue(el)
+            );
+        });
+        return false;
+      }
+    }
+
+    if (isVisitable(value)) {
+      return true;
+    }
+
+    formData.append(renderKey(path, key, dots), convertValue(value));
+
+    return false;
+  }
+
+  const stack = [];
+
+  const exposedHelpers = Object.assign(predicates, {
+    defaultVisitor,
+    convertValue,
+    isVisitable,
+  });
+
+  function build(value, path, depth = 0) {
+    if (utils.isUndefined(value)) return;
+
+    if (depth > maxDepth) {
+      throw new AxiosError(
+        'Object is too deeply nested (' + depth + ' levels). Max depth: ' + maxDepth,
+        AxiosError.ERR_FORM_DATA_DEPTH_EXCEEDED
+      );
+    }
+
+    if (stack.indexOf(value) !== -1) {
+      throw new Error('Circular reference detected in ' + path.join('.'));
+    }
+
+    stack.push(value);
+
+    utils.forEach(value, function each(el, key) {
+      const result =
+        !(utils.isUndefined(el) || el === null) &&
+        visitor.call(formData, el, utils.isString(key) ? key.trim() : key, path, exposedHelpers);
+
+      if (result === true) {
+        build(el, path ? path.concat(key) : [key], depth + 1);
+      }
+    });
+
+    stack.pop();
+  }
+
+  if (!utils.isObject(obj)) {
+    throw new TypeError('data must be an object');
+  }
+
+  build(obj);
+
+  return formData;
+}
+
+export default toFormData;
@@ -0,0 +1,19 @@
+'use strict';
+
+import utils from '../utils.js';
+import toFormData from './toFormData.js';
+import platform from '../platform/index.js';
+
+export default function toURLEncodedForm(data, options) {
+  return toFormData(data, new platform.classes.URLSearchParams(), {
+    visitor: function (value, key, path, helpers) {
+      if (platform.isNode && utils.isBuffer(value)) {
+        this.append(key, value.toString('base64'));
+        return false;
+      }
+
+      return helpers.defaultVisitor.apply(this, arguments);
+    },
+    ...options,
+  });
+}
@@ -0,0 +1,89 @@
+export const streamChunk = function* (chunk, chunkSize) {
+  let len = chunk.byteLength;
+
+  if (!chunkSize || len < chunkSize) {
+    yield chunk;
+    return;
+  }
+
+  let pos = 0;
+  let end;
+
+  while (pos < len) {
+    end = pos + chunkSize;
+    yield chunk.slice(pos, end);
+    pos = end;
+  }
+};
+
+export const readBytes = async function* (iterable, chunkSize) {
+  for await (const chunk of readStream(iterable)) {
+    yield* streamChunk(chunk, chunkSize);
+  }
+};
+
+const readStream = async function* (stream) {
+  if (stream[Symbol.asyncIterator]) {
+    yield* stream;
+    return;
+  }
+
+  const reader = stream.getReader();
+  try {
+    for (;;) {
+      const { done, value } = await reader.read();
+      if (done) {
+        break;
+      }
+      yield value;
+    }
+  } finally {
+    await reader.cancel();
+  }
+};
+
+export const trackStream = (stream, chunkSize, onProgress, onFinish) => {
+  const iterator = readBytes(stream, chunkSize);
+
+  let bytes = 0;
+  let done;
+  let _onFinish = (e) => {
+    if (!done) {
+      done = true;
+      onFinish && onFinish(e);
+    }
+  };
+
+  return new ReadableStream(
+    {
+      async pull(controller) {
+        try {
+          const { done, value } = await iterator.next();
+
+          if (done) {
+            _onFinish();
+            controller.close();
+            return;
+          }
+
+          let len = value.byteLength;
+          if (onProgress) {
+            let loadedBytes = (bytes += len);
+            onProgress(loadedBytes);
+          }
+          controller.enqueue(new Uint8Array(value));
+        } catch (err) {
+          _onFinish(err);
+          throw err;
+        }
+      },
+      cancel(reason) {
+        _onFinish(reason);
+        return iterator.return();
+      },
+    },
+    {
+      highWaterMark: 2,
+    }
+  );
+};
@@ -1,34 +1,48 @@
 'use strict';

-var VERSION = require('../env/data').version;
+import { VERSION } from '../env/data.js';
+import AxiosError from '../core/AxiosError.js';

-var validators = {};
+const validators = {};

 // eslint-disable-next-line func-names
-['object', 'boolean', 'number', 'function', 'string', 'symbol'].forEach(function(type, i) {
+['object', 'boolean', 'number', 'function', 'string', 'symbol'].forEach((type, i) => {
  validators[type] = function validator(thing) {
    return typeof thing === type || 'a' + (i < 1 ? 'n ' : ' ') + type;
  };
 });

-var deprecatedWarnings = {};
+const deprecatedWarnings = {};

 /**
 * Transitional option validator
+ *
 * @param {function|boolean?} validator - set to false if the transitional option has been removed
 * @param {string?} version - deprecated version / removed since version
 * @param {string?} message - some message with additional info
+ *
 * @returns {function}
 */
 validators.transitional = function transitional(validator, version, message) {
  function formatMessage(opt, desc) {
-    return '[Axios v' + VERSION + '] Transitional option \'' + opt + '\'' + desc + (message ? '. ' + message : '');
+    return (
+      '[Axios v' +
+      VERSION +
+      "] Transitional option '" +
+      opt +
+      "'" +
+      desc +
+      (message ? '. ' + message : '')
+    );
  }

  // eslint-disable-next-line func-names
-  return function(value, opt, opts) {
+  return (value, opt, opts) => {
    if (validator === false) {
-      throw new Error(formatMessage(opt, ' has been removed' + (version ? ' in ' + version : '')));
+      throw new AxiosError(
+        formatMessage(opt, ' has been removed' + (version ? ' in ' + version : '')),
+        AxiosError.ERR_DEPRECATED
+      );
    }

    if (version && !deprecatedWarnings[opt]) {
@@ -46,37 +60,53 @@ validators.transitional = function transitional(validator, version, message) {
  };
 };

+validators.spelling = function spelling(correctSpelling) {
+  return (value, opt) => {
+    // eslint-disable-next-line no-console
+    console.warn(`${opt} is likely a misspelling of ${correctSpelling}`);
+    return true;
+  };
+};
+
 /**
 * Assert object's properties type
+ *
 * @param {object} options
 * @param {object} schema
 * @param {boolean?} allowUnknown
+ *
+ * @returns {object}
 */

 function assertOptions(options, schema, allowUnknown) {
  if (typeof options !== 'object') {
-    throw new TypeError('options must be an object');
+    throw new AxiosError('options must be an object', AxiosError.ERR_BAD_OPTION_VALUE);
  }
-  var keys = Object.keys(options);
-  var i = keys.length;
+  const keys = Object.keys(options);
+  let i = keys.length;
  while (i-- > 0) {
-    var opt = keys[i];
-    var validator = schema[opt];
+    const opt = keys[i];
+    // Use hasOwnProperty so a polluted Object.prototype.<opt> cannot supply
+    // a non-function validator and cause a TypeError.
+    const validator = Object.prototype.hasOwnProperty.call(schema, opt) ? schema[opt] : undefined;
    if (validator) {
-      var value = options[opt];
-      var result = value === undefined || validator(value, opt, options);
+      const value = options[opt];
+      const result = value === undefined || validator(value, opt, options);
      if (result !== true) {
-        throw new TypeError('option ' + opt + ' must be ' + result);
+        throw new AxiosError(
+          'option ' + opt + ' must be ' + result,
+          AxiosError.ERR_BAD_OPTION_VALUE
+        );
      }
      continue;
    }
    if (allowUnknown !== true) {
-      throw Error('Unknown option ' + opt);
+      throw new AxiosError('Unknown option ' + opt, AxiosError.ERR_BAD_OPTION);
    }
  }
 }

-module.exports = {
-  assertOptions: assertOptions,
-  validators: validators
+export default {
+  assertOptions,
+  validators,
 };