Adding cancellation support

lib/core/dispatchRequest.js

@@ -2,6 +2,16 @@
 
 var utils = require('./../utils');
 var transformData = require('./transformData');
+var Cancel = require('../cancel/Cancel');
+
+/**
+ * Throws a `Cancel` if cancellation has been requested.
+ */
+function throwIfCancellationRequested(config) {
+  if (config.cancelToken) {
+    config.cancelToken.throwIfRequested();
+  }
+}
 
 /**
  * Dispatch a request to the server using whichever adapter
@@ -11,6 +21,8 @@ var transformData = require('./transformData');
  * @returns {Promise} The Promise to be fulfilled
  */
 module.exports = function dispatchRequest(config) {
+  throwIfCancellationRequested(config);
+
   // Ensure headers exist
   config.headers = config.headers || {};
 
@@ -52,6 +64,8 @@ module.exports = function dispatchRequest(config) {
     // Wrap synchronous adapter errors and pass configuration
     .then(adapter)
     .then(function onFulfilled(response) {
+      throwIfCancellationRequested(config);
+
       // Transform response data
       response.data = transformData(
         response.data,
@@ -60,16 +74,20 @@ module.exports = function dispatchRequest(config) {
       );
 
       return response;
-    }, function onRejected(error) {
-      // Transform response data
-      if (error && error.response) {
-        error.response.data = transformData(
-          error.response.data,
-          error.response.headers,
-          config.transformResponse
-        );
+    }, function onRejected(reason) {
+      if (!(reason instanceof Cancel)) {
+        throwIfCancellationRequested(config);
+
+        // Transform response data
+        if (reason && reason.response) {
+          reason.response.data = transformData(
+            reason.response.data,
+            reason.response.headers,
+            config.transformResponse
+          );
+        }
       }
 
-      return Promise.reject(error);
+      return Promise.reject(reason);
     });
 };