Breaking up complexity of main axios file

lib/axios.js

@@ -1,131 +1,92 @@
 var Promise = require('es6-promise').Promise;
+var defaults = require('./defaults');
+var forEach = require('./forEach');
+var merge = require('./merge');
+var transformData = require('./transformData');
 
-function axios(options) {
+var axios = module.exports = function axios(options) {
   options = merge({
     method: 'get',
     transformRequest: defaults.transformRequest,
     transformResponse: defaults.transformResponse
   }, options);
 
   var promise = new Promise(function (resolve, reject) {
-    var request = new(XMLHttpRequest || ActiveXObject)('MSXML2.XMLHTTP.3.0');
-
-    function onload() {
-      if (request.status >= 200 && request.status < 300) {
-        resolve(transformData(request.responseText, options.headers, options.transformResponse));
-      } else {
-        onerror();
-      }
-    }
-
-    function onerror() {
-      reject(
-        parse(request.responseText) ||
-        new Error('Can\'t connect to ' + JSON.stringify(options.url))
-      );
-    }
-
-    try {
-      request.open(options.method, options.url, true);
-      request.onreadystatechange = function () {
-        if (request.readyState === 4) {
-          onload();
+    var request = new(XMLHttpRequest || ActiveXObject)('Microsoft.XMLHTTP');
+    var data = transformData(options.data, options.headers, options.transformRequest);
+
+    // Open request and listen for ready state
+    request.open(options.method, options.url, true);
+    request.onreadystatechange = function () {
+      if (request && request.readyState === 4) {
+        // Prepare the response
+        var response = {
+          data: transformData(request.responseText, options.headers, options.transformResponse),
+          status: request.status,
+          headers: headers,
+          config: options
+        };
+
+        // Resolve or reject the Promise based on the status
+        if (request.status >= 200 && request.status < 300) {
+          resolve(response);
+        } else {
+          reject(response);
         }
-      };
 
-      request.onload = request.load = onload;
-      request.onerror = request.error = onerror;
-
-      var headers = merge(
-        defaults.headers.common,
-        defaults.headers[options.method] || {},
-        options.headers || {}
-      );
+        // Clean up request
+        request = null;
+      }
+    };
 
-      for (var key in headers) {
-        if (headers.hasOwnProperty(key)) {
-          request.setRequestHeader(key, headers[key]);
-        }
+    // Merge headers and add to request
+    var headers = merge(
+      defaults.headers.common,
+      defaults.headers[options.method] || {},
+      options.headers || {}
+    );
+
+    forEach(headers, function (val, key) {
+      // Remove Content-Type if data is undefined
+      if (typeof data === 'undefined' &&
+          key.toLowerCase() === 'content-type') {
+        delete headers[key];
       }
-    } catch (e) {
-      reject(e);
-    }
+      // Otherwise add header to the request
+      else {
+        request.setRequestHeader(key, val);
+      }
+    });
 
-    request.send(transformData(options.data, options.headers, options.transformRequest));
+    // Send the request
+    request.send(data);
   });
 
-  promise.success = function (fn) {
+  // Provide alias for success
+  promise.success = function success(fn) {
     promise.then(function(response) {
       fn(response);
     });
     return promise;
   };
 
-  promise.error = function(fn) {
+  // Provide alias for error
+  promise.error = function error(fn) {
     promise.then(null, function(response) {
       fn(response);
     });
     return promise;
   };
 
   return promise;
-}
-
-var CONTENT_TYPE_APPLICATION_JSON = {'Content-Type': 'application/json;charset=utf-8'};
-var defaults = axios.defaults = {
-  transformRequest: [function (data) {
-    return data ? JSON.stringify(data) : null;
-  }],
-
-  transformResponse: [function (data) {
-    return parse(data);
-  }],
-
-  headers: {
-    common: {'Accept': 'application/json, text/plain, */*'},
-    patch: merge(CONTENT_TYPE_APPLICATION_JSON),
-    post: merge(CONTENT_TYPE_APPLICATION_JSON),
-    put: merge(CONTENT_TYPE_APPLICATION_JSON)
-  }
 };
 
-function transformData(data, headers, fns) {
-  if (typeof fns === 'function') {
-    return fns(data, headers);
-  }
-
-  forEach(fns, function (fn) {
-    data = fn(data, headers);
-  });
-
-  return data;
-}
-
-function parse(response) {
-  try {
-    return JSON.parse(response);
-  } catch(e) {
-    return response;
-  }
-}
-
-function merge() {
-  var result = {};
-  forEach(arguments, function (obj) {
-    for (var key in obj) {
-      if (obj.hasOwnProperty(key)) {
-        result[key] = obj[key];
-      }
-    }
-  });
-  return result;
-}
+// Expose defaults
+axios.defaults = defaults;
 
-function forEach(arr, fn) {
-  for (var i=0, l=arr.length; i<l; i++) {
-    fn.call(null, arr[i], i, arr);
-  }
-}
+// Provide aliases for supported request methods
+createShortMethods('delete', 'get', 'head');
+createShortMethodsWithData('post', 'put', 'patch');
 
 function createShortMethods() {
   forEach(arguments, function (method) {
@@ -148,9 +109,4 @@ function createShortMethodsWithData() {
       }));
     };
   });
-}
-
-createShortMethods('delete', 'get', 'head');
-createShortMethodsWithData('post', 'put', 'patch');
-
-module.exports = axios;
+}

lib/defaults.js

@@ -0,0 +1,42 @@
+'use strict';
+
+var merge = require('./merge');
+
+var toString = Object.prototype.toString;
+var JSON_START = /^\s*(\[|\{[^\{])/;
+var JSON_END = /[\}\]]\s*$/;
+var PROTECTION_PREFIX = /^\)\]\}',?\n/;
+var CONTENT_TYPE_APPLICATION_JSON = {
+  'Content-Type': 'application/json;charset=utf-8'
+};
+
+module.exports = {
+  transformRequest: [function (data) {
+    return data !== null && typeof data === 'object' &&
+          toString.call(data) !== '[object File]' &&
+          toString.call(data) !== '[object Blob]' ?
+            JSON.stringify(data) : null;
+  }],
+
+  transformResponse: [function (data) {
+    if (typeof data === 'string') {
+      data = data.replace(PROTECTION_PREFIX, '');
+      if (JSON_START.test(data) && JSON_END.test(data)) {
+        data = JSON.parse(data);
+      }
+    }
+    return data;
+  }],
+
+  headers: {
+    common: {
+      'Accept': 'application/json, text/plain, */*'
+    },
+    patch: merge(CONTENT_TYPE_APPLICATION_JSON),
+    post: merge(CONTENT_TYPE_APPLICATION_JSON),
+    put: merge(CONTENT_TYPE_APPLICATION_JSON)
+  },
+
+  xsrfCookiName: 'XSRF-TOKEN',
+  xsrfHeaderName: 'X-XSRF-TOKEN'
+};

lib/forEach.js

@@ -0,0 +1,34 @@
+'use strict';
+
+/**
+ * Iterate over an Array or an Object invoking a function for each item.
+ *
+ * If `obj` is an Array or arguments 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
+ */
+module.exports = function forEach(obj, fn) {
+  if (typeof obj !== 'object') {
+    return;
+  }
+
+  // Iterate over array values
+  if (obj.constructor === Array || typeof obj.callee === 'function') {
+    for (var i=0, l=obj.length; i<l; i++) {
+      fn.call(null, obj[i], i, obj);
+    }
+  }
+  // Iterate over object keys
+  else {
+    for (var key in obj) {
+      if (obj.hasOwnProperty(key)) {
+        fn.call(null, obj[key], key, obj);
+      }
+    }
+  }
+};

lib/merge.js

@@ -0,0 +1,28 @@
+var forEach = require('./forEach');
+
+/**
+ * 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
+ */
+module.exports = function merge(obj1/*, obj2, obj3, ...*/) {
+  var result = {};
+  forEach(arguments, function (obj) {
+    forEach(obj, function (val, key) {
+      result[key] = val;
+    });
+  });
+  return result;
+};

lib/transformData.js

@@ -0,0 +1,23 @@
+'use strict';
+
+var forEach = require('./forEach');
+
+/**
+ * Transform the data for a request or a response
+ *
+ * @param {Object|String} data The data to be transformed
+ * @param {Array} headers The headers for the request or response
+ * @param {Array|Function} fns A single function or Array of functions
+ * @returns {*} The resulting transformed data
+ */
+module.exports = function transformData(data, headers, fns) {
+  if (typeof fns === 'function') {
+    return fns(data, headers);
+  }
+
+  forEach(fns, function (fn) {
+    data = fn(data, headers);
+  });
+
+  return data;
+};

test/unit/forEach.js

@@ -0,0 +1,33 @@
+var forEach = require('../../lib/forEach');
+
+module.exports = {
+  testArray: function (test) {
+    var sum = 0;
+
+    forEach([1, 2, 3, 4, 5], function (val) {
+      sum += val;
+    });
+
+    test.equal(sum, 15);
+    test.done();
+  },
+
+  testObject: function (test) {
+    var keys = '';
+    var vals = 0;
+    var obj = {
+      b: 1,
+      a: 2,
+      r: 3
+    };
+
+    forEach(obj, function (v, k) {
+      keys += k;
+      vals += v;
+    });
+
+    test.equal(keys, 'bar');
+    test.equal(vals, 6);
+    test.done();
+  }
+};