utils.ts

"use strict";

import bind from "./helpers/bind";

// utils is a library of generic helper functions non-specific to axios

var toString = Object.prototype.toString;

// eslint-disable-next-line func-names
var kindOf = (function (cache) {
  // eslint-disable-next-line func-names
  return function (thing) {
    var str = toString.call(thing);
    return cache[str] || (cache[str] = str.slice(8, -1).toLowerCase());
  };
})(Object.create(null));

function kindOfTest(type) {
  type = type.toLowerCase();
  return function isKindOf(thing) {
    return kindOf(thing) === type;
  };
}

/**
 * Determine if a value is an Array
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is an Array, otherwise false
 */
function isArray(val) {
  return Array.isArray(val);
}

/**
 * Determine if a value is undefined
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if the value is undefined, otherwise false
 */
function isUndefined(val) {
  return typeof val === "undefined";
}

/**
 * Determine if a value is a Buffer
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a Buffer, otherwise false
 */
function isBuffer(val) {
  return (
    val !== null &&
    !isUndefined(val) &&
    val.constructor !== null &&
    !isUndefined(val.constructor) &&
    typeof val.constructor.isBuffer === "function" &&
    val.constructor.isBuffer(val)
  );
}

/**
 * Determine if a value is an ArrayBuffer
 *
 * @function
 * @param {Object} val The value to test
 * @returns {boolean} True if value is an ArrayBuffer, otherwise false
 */
var isArrayBuffer = kindOfTest("ArrayBuffer");

/**
 * Determine if a value is a view on an ArrayBuffer
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a view on an ArrayBuffer, otherwise false
 */
function isArrayBufferView(val) {
  var result;
  if (typeof ArrayBuffer !== "undefined" && ArrayBuffer.isView) {
    result = ArrayBuffer.isView(val);
  } else {
    result = val && val.buffer && isArrayBuffer(val.buffer);
  }
  return result;
}

/**
 * Determine if a value is a String
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a String, otherwise false
 */
function isString(val) {
  return typeof val === "string";
}

/**
 * Determine if a value is a Number
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a Number, otherwise false
 */
function isNumber(val) {
  return typeof val === "number";
}

/**
 * Determine if a value is an Object
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is an Object, otherwise false
 */
function isObject(val) {
  return val !== null && typeof val === "object";
}

/**
 * Determine if a value is a plain Object
 *
 * @param {Object} val The value to test
 * @return {boolean} True if value is a plain Object, otherwise false
 */
function isPlainObject(val) {
  if (kindOf(val) !== "object") {
    return false;
  }

  var prototype = Object.getPrototypeOf(val);
  return prototype === null || prototype === Object.prototype;
}

/**
 * Determine if a value is a Date
 *
 * @function
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a Date, otherwise false
 */
var isDate = kindOfTest("Date");

/**
 * Determine if a value is a File
 *
 * @function
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a File, otherwise false
 */
var isFile = kindOfTest("File");

/**
 * Determine if a value is a Blob
 *
 * @function
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a Blob, otherwise false
 */
var isBlob = kindOfTest("Blob");

/**
 * Determine if a value is a FileList
 *
 * @function
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a File, otherwise false
 */
var isFileList = kindOfTest("FileList");

/**
 * Determine if a value is a Function
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a Function, otherwise false
 */
function isFunction(val) {
  return toString.call(val) === "[object Function]";
}

/**
 * Determine if a value is a Stream
 *
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a Stream, otherwise false
 */
function isStream(val) {
  return isObject(val) && isFunction(val.pipe);
}

/**
 * Determine if a value is a FormData
 *
 * @param {Object} thing The value to test
 * @returns {boolean} True if value is an FormData, otherwise false
 */
function isFormData(thing) {
  var pattern = "[object FormData]";
  return (
    thing &&
    ((typeof FormData === "function" && thing instanceof FormData) ||
      toString.call(thing) === pattern ||
      (isFunction(thing.toString) && thing.toString() === pattern))
  );
}

/**
 * Determine if a value is a URLSearchParams object
 * @function
 * @param {Object} val The value to test
 * @returns {boolean} True if value is a URLSearchParams object, otherwise false
 */
var isURLSearchParams = kindOfTest("URLSearchParams");

/**
 * Trim excess whitespace off the beginning and end of a string
 *
 * @param {String} str The String to trim
 * @returns {String} The String freed of excess whitespace
 */
function trim(str) {
  return str.trim ? str.trim() : str.replace(/^\s+|\s+$/g, "");
}

/**
 * Determine if we're running in a standard browser environment
 *
 * This allows axios to run in a web worker, and react-native.
 * Both environments support XMLHttpRequest, but not fully standard globals.
 *
 * web workers:
 *  typeof window -> undefined
 *  typeof document -> undefined
 *
 * react-native:
 *  navigator.product -> 'ReactNative'
 * nativescript
 *  navigator.product -> 'NativeScript' or 'NS'
 */
function isStandardBrowserEnv() {
  if (
    typeof navigator !== "undefined" &&
    (navigator.product === "ReactNative" ||
      navigator.product === "NativeScript" ||
      navigator.product === "NS")
  ) {
    return false;
  }
  return typeof window !== "undefined" && typeof document !== "undefined";
}

/**
 * Iterate over an Array or an Object invoking a function for each item.
 *
 * If `obj` is an Array callback will be called passing
 * the value, index, and complete array for each item.
 *
 * If 'obj' is an Object callback will be called passing
 * the value, key, and complete object for each property.
 *
 * @param {Object|Array} obj The object to iterate
 * @param {Function} fn The callback to invoke for each item
 */
function forEach(obj, fn) {
  // Don't bother if no value provided
  if (obj === null || typeof obj === "undefined") {
    return;
  }

  // Force an array if not already something iterable
  if (typeof obj !== "object") {
    /*eslint no-param-reassign:0*/
    obj = [obj];
  }

  if (isArray(obj)) {
    // Iterate over array values
    for (var i = 0, l = obj.length; i < l; i++) {
      fn.call(null, obj[i], i, obj);
    }
  } else {
    // Iterate over object keys
    for (var key in obj) {
      if (Object.prototype.hasOwnProperty.call(obj, key)) {
        fn.call(null, obj[key], key, obj);
      }
    }
  }
}

/**
 * Accepts varargs expecting each argument to be an object, then
 * immutably merges the properties of each object and returns result.
 *
 * When multiple objects contain the same key the later object in
 * the arguments list will take precedence.
 *
 * Example:
 *
 * ```js
 * var result = merge({foo: 123}, {foo: 456});
 * console.log(result.foo); // outputs 456
 * ```
 *
 * @param {Object} obj1 Object to merge
 * @returns {Object} Result of all merge properties
 */
function merge(/* obj1, obj2, obj3, ... */) {
  var result = {};
  function assignValue(val, key) {
    if (isPlainObject(result[key]) && isPlainObject(val)) {
      // @ts-ignore
      result[key] = merge(result[key], val);
    } else if (isPlainObject(val)) {
      // @ts-ignore
      result[key] = merge({}, val);
    } else if (isArray(val)) {
      result[key] = val.slice();
    } else {
      result[key] = val;
    }
  }

  for (var i = 0, l = arguments.length; i < l; i++) {
    forEach(arguments[i], assignValue);
  }
  return result;
}

/**
 * Extends object a by mutably adding to it the properties of object b.
 *
 * @param {Object} a The object to be extended
 * @param {Object} b The object to copy properties from
 * @param {Object} thisArg The object to bind function to
 * @return {Object} The resulting value of object a
 */
function extend(a, b, thisArg) {
  forEach(b, function assignValue(val, key) {
    if (thisArg && typeof val === "function") {
      a[key] = bind(val, thisArg);
    } else {
      a[key] = val;
    }
  });
  return a;
}

/**
 * Remove byte order marker. This catches EF BB BF (the UTF-8 BOM)
 *
 * @param {string} content with BOM
 * @return {string} content value without BOM
 */
function stripBOM(content) {
  if (content.charCodeAt(0) === 0xfeff) {
    content = content.slice(1);
  }
  return content;
}

/**
 * Inherit the prototype methods from one constructor into another
 * @param {function} constructor
 * @param {function} superConstructor
 * @param {object} [props]
 * @param {object} [descriptors]
 */

function inherits(constructor, superConstructor, props, descriptors) {
  constructor.prototype = Object.create(
    superConstructor.prototype,
    descriptors
  );
  constructor.prototype.constructor = constructor;
  props && Object.assign(constructor.prototype, props);
}

/**
 * Resolve object with deep prototype chain to a flat object
 * @param {Object} sourceObj source object
 * @param {Object} [destObj]
 * @param {Function} [filter]
 * @returns {Object}
 */

function toFlatObject(sourceObj, destObj, filter) {
  var props;
  var i;
  var prop;
  var merged = {};

  destObj = destObj || {};

  do {
    props = Object.getOwnPropertyNames(sourceObj);
    i = props.length;
    while (i-- > 0) {
      prop = props[i];
      if (!merged[prop]) {
        destObj[prop] = sourceObj[prop];
        merged[prop] = true;
      }
    }
    sourceObj = Object.getPrototypeOf(sourceObj);
  } while (
    sourceObj &&
    (!filter || filter(sourceObj, destObj)) &&
    sourceObj !== Object.prototype
  );

  return destObj;
}

/*
 * determines whether a string ends with the characters of a specified string
 * @param {String} str
 * @param {String} searchString
 * @param {Number} [position= 0]
 * @returns {boolean}
 */
function endsWith(str, searchString, position) {
  str = String(str);
  if (position === undefined || position > str.length) {
    position = str.length;
  }
  position -= searchString.length;
  var lastIndex = str.indexOf(searchString, position);
  return lastIndex !== -1 && lastIndex === position;
}

/**
 * Returns new array from array like object
 * @param {*} [thing]
 * @returns {Array}
 */
function toArray(thing) {
  if (!thing) return null;
  var i = thing.length;
  if (isUndefined(i)) return null;
  var arr = new Array(i);
  while (i-- > 0) {
    arr[i] = thing[i];
  }
  return arr;
}

// eslint-disable-next-line func-names
var isTypedArray = (function (TypedArray) {
  // eslint-disable-next-line func-names
  return function (thing) {
    return TypedArray && thing instanceof TypedArray;
  };
})(typeof Uint8Array !== "undefined" && Object.getPrototypeOf(Uint8Array));

export { isArray };
export { isArrayBuffer };
export { isBuffer };
export { isFormData };
export { isArrayBufferView };
export { isString };
export { isNumber };
export { isObject };
export { isPlainObject };
export { isUndefined };
export { isDate };
export { isFile };
export { isBlob };
export { isFunction };
export { isStream };
export { isURLSearchParams };
export { isStandardBrowserEnv };
export { forEach };
export { merge };
export { extend };
export { trim };
export { stripBOM };
export { inherits };
export { toFlatObject };
export { kindOf };
export { kindOfTest };
export { endsWith };
export { toArray };
export { isTypedArray };
export { isFileList };

export default {
  isArray,
  isArrayBuffer,
  isBuffer,
  isFormData,
  isArrayBufferView,
  isString,
  isNumber,
  isObject,
  isPlainObject,
  isUndefined,
  isDate,
  isFile,
  isBlob,
  isFunction,
  isStream,
  isURLSearchParams,
  isStandardBrowserEnv,
  forEach,
  merge,
  extend,
  trim,
  stripBOM,
  inherits,
  toFlatObject,
  kindOf,
  kindOfTest,
  endsWith,
  toArray,
  isTypedArray,
  isFileList,
};