Breaking up complexity of main axios file

lib/axios.js

@@ -1,6 +1,10 @@
 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,
@@ -8,60 +12,66 @@ function axios(options) {
   }, options);
 
   var promise = new Promise(function (resolve, reject) {
-    var request = new(XMLHttpRequest || ActiveXObject)('MSXML2.XMLHTTP.3.0');
+    var request = new(XMLHttpRequest || ActiveXObject)('Microsoft.XMLHTTP');
+    var data = transformData(options.data, options.headers, options.transformRequest);
 
-    function onload() {
-      if (request.status >= 200 && request.status < 300) {
-        resolve(transformData(request.responseText, options.headers, options.transformResponse));
-      } else {
-        onerror();
-      }
-    }
+    // 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
+        };
 
-    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();
+        // 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 || {}
-      );
-
-      for (var key in headers) {
-        if (headers.hasOwnProperty(key)) {
-          request.setRequestHeader(key, headers[key]);
-        }
+        // Clean up request
+        request = null;
       }
-    } catch (e) {
-      reject(e);
-    }
+    };
 
-    request.send(transformData(options.data, options.headers, options.transformRequest));
+    // 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];
+      }
+      // Otherwise add header to the request
+      else {
+        request.setRequestHeader(key, val);
+      }
+    });
+
+    // 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);
     });
@@ -69,63 +79,14 @@ function axios(options) {
   };
 
   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);
-  }
+// Expose defaults
+axios.defaults = defaults;
 
-  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;
-}
-
-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;
+}