Initial interceptor implementation.

lib/axios.js

@@ -13,20 +13,22 @@ var axios = module.exports = function axios(config) {
   // Don't allow overriding defaults.withCredentials
   config.withCredentials = config.withCredentials || defaults.withCredentials;
 
-  var promise = new Promise(function (resolve, reject) {
-    try {
-      // For browsers use XHR adapter
-      if (typeof window !== 'undefined') {
-        require('./adapters/xhr')(resolve, reject, config);
+  var serverRequest = function (config) {
+    return new Promise(function (resolve, reject) {
+      try {
+        // For browsers use XHR adapter
+        if (typeof window !== 'undefined') {
+          require('./adapters/xhr')(resolve, reject, config);
+        }
+        // For node use HTTP adapter
+        else if (typeof process !== 'undefined') {
+          require('./adapters/http')(resolve, reject, config);
+        }
+      } catch (e) {
+        reject(e);
       }
-      // For node use HTTP adapter
-      else if (typeof process !== 'undefined') {
-        require('./adapters/http')(resolve, reject, config);
-      }
-    } catch (e) {
-      reject(e);
-    }
-  });
+    });
+  };
 
   function deprecatedMethod(method, instead, docs) {
     try {
@@ -41,6 +43,24 @@ var axios = module.exports = function axios(config) {
     } catch (e) {}
   }
 
+  var chain = [serverRequest, undefined];
+  var promise = Promise.resolve(config);
+
+  utils.forEach(axios.interceptors.request.handlers, function (interceptor) {
+    chain.unshift(interceptor.request, interceptor.requestError);
+  });
+
+  utils.forEach(axios.interceptors.response.handlers, function (interceptor) {
+    chain.push(interceptor.response, interceptor.responseError);
+  });
+
+  while (chain.length) {
+    var thenFn = chain.shift();
+    var rejectFn = chain.shift();
+
+    promise = promise.then(thenFn, rejectFn);
+  }
+
   // Provide alias for success
   promise.success = function success(fn) {
     deprecatedMethod('success', 'then', 'https://github.com/mzabriskie/axios/blob/master/README.md#response-api');
@@ -73,6 +93,22 @@ axios.all = function (promises) {
 };
 axios.spread = require('./helpers/spread');
 
+// interceptors
+axios.interceptors = {
+  request: {
+    handlers: [],
+    use: function (thenFn, rejectFn) {
+      axios.interceptors.request.handlers.push({ request: thenFn, requestError: rejectFn });
+    }
+  },
+  response: {
+    handlers: [],
+    use: function (thenFn, rejectFn) {
+      axios.interceptors.response.handlers.push({ response: thenFn, responseError: rejectFn });
+    }
+  }
+};
+
 // Provide aliases for supported request methods
 createShortMethods('delete', 'get', 'head');
 createShortMethodsWithData('post', 'put', 'patch');
@@ -98,4 +134,4 @@ function createShortMethodsWithData() {
       }));
     };
   });
-}
+}