Improve error handling

README.md

@@ -56,8 +56,8 @@ axios.get('/user?ID=12345')
   .then(function (response) {
     console.log(response);
   })
-  .catch(function (response) {
-    console.log(response);
+  .catch(function (error) {
+    console.log(error);
   });
 
 // Optionally the request above could also be done as
@@ -69,8 +69,8 @@ axios.get('/user', {
   .then(function (response) {
     console.log(response);
   })
-  .catch(function (response) {
-    console.log(response);
+  .catch(function (error) {
+    console.log(error);
   });
 ```
 
@@ -84,8 +84,8 @@ axios.post('/user', {
   .then(function (response) {
     console.log(response);
   })
-  .catch(function (response) {
-    console.log(response);
+  .catch(function (error) {
+    console.log(error);
   });
 ```
 
@@ -414,18 +414,18 @@ instance.interceptors.request.use(function () {/*...*/});
 
 ```js
 axios.get('/user/12345')
-  .catch(function (response) {
-    if (response instanceof Error) {
-      // Something happened in setting up the request that triggered an Error
-      console.log('Error', response.message);
-    } else {
+  .catch(function (error) {
+    if (error.response) {
       // The request was made, but the server responded with a status code
       // that falls out of the range of 2xx
-      console.log(response.data);
-      console.log(response.status);
-      console.log(response.headers);
-      console.log(response.config);
+      console.log(error.response.data);
+      console.log(error.response.status);
+      console.log(error.response.headers);
+    } else {
+      // Something happened in setting up the request that triggered an Error
+      console.log('Error', error.message);
     }
+    console.log(error.config);
   });
 ```
 

examples/get/index.html

@@ -20,13 +20,13 @@
                   '<strong>' + person.name + '</strong>' +
                   '<div>Github: <a href="https://github.com/' + person.github + '" target="_blank">' + person.github + '</a></div>' +
                   '<div>Twitter: <a href="https://twitter.com/' + person.twitter + '" target="_blank">' + person.twitter + '</a></div>' +
-                '</div>' + 
+                '</div>' +
               '</li><br/>'
             );
           }).join('');
         })
-        .catch(function(data) {
-          document.getElementById('people').innerHTML = '<li class="text-danger">' + data + '</li>';
+        .catch(function (err) {
+          document.getElementById('people').innerHTML = '<li class="text-danger">' + err.message + '</li>';
         });
     </script>
   </body>

examples/post/index.html

@@ -29,9 +29,9 @@
               output.className = 'container';
               output.innerHTML = res.data;
             })
-            .catch(function (res) {
+            .catch(function (err) {
               output.className = 'container text-danger';
-              output.innerHTML = res.data;
+              output.innerHTML = err.message;
             });
         };
       })();

examples/upload/index.html

@@ -37,9 +37,9 @@
               output.className = 'container';
               output.innerHTML = res.data;
             })
-            .catch(function (res) {
+            .catch(function (err) {
               output.className = 'container text-danger';
-              output.innerHTML = res.data;
+              output.innerHTML = err.message;
             });
         };
       })();

lib/adapters/http.js

@@ -12,6 +12,8 @@ var url = require('url');
 var zlib = require('zlib');
 var pkg = require('./../../package.json');
 var Buffer = require('buffer').Buffer;
+var createError = require('../core/createError');
+var enhanceError = require('../core/enhanceError');
 
 /*eslint consistent-return:0*/
 module.exports = function httpAdapter(resolve, reject, config) {
@@ -33,7 +35,10 @@ module.exports = function httpAdapter(resolve, reject, config) {
     } else if (utils.isString(data)) {
       data = new Buffer(data, 'utf-8');
     } else {
-      return reject(new Error('Data after transformation must be a string, an ArrayBuffer, or a Stream'));
+      return reject(createError(
+        'Data after transformation must be a string, an ArrayBuffer, or a Stream',
+        config
+      ));
     }
 
     // Add Content-Length header if data exists
@@ -122,13 +127,13 @@ module.exports = function httpAdapter(resolve, reject, config) {
 
         // make sure the content length is not over the maxContentLength if specified
         if (config.maxContentLength > -1 && Buffer.concat(responseBuffer).length > config.maxContentLength) {
-          reject(new Error('maxContentLength size of ' + config.maxContentLength + ' exceeded'));
+          reject(createError('maxContentLength size of ' + config.maxContentLength + ' exceeded', config));
         }
       });
 
       stream.on('error', function handleStreamError(err) {
         if (aborted) return;
-        reject(err);
+        reject(enhanceError(err, config));
       });
 
       stream.on('end', function handleStreamEnd() {
@@ -145,17 +150,14 @@ module.exports = function httpAdapter(resolve, reject, config) {
   // Handle errors
   req.on('error', function handleRequestError(err) {
     if (aborted) return;
-    reject(err);
+    reject(enhanceError(err, config));
   });
 
   // Handle request timeout
   if (config.timeout && !timer) {
     timer = setTimeout(function handleRequestTimeout() {
-      var err = new Error('timeout of ' + config.timeout + 'ms exceeded');
-      err.timeout = config.timeout;
-      err.code = 'ECONNABORTED';
       req.abort();
-      reject(err);
+      reject(createError('timeout of ' + config.timeout + 'ms exceeded', config, 'ECONNABORTED'));
       aborted = true;
     }, config.timeout);
   }

lib/adapters/xhr.js

@@ -6,6 +6,7 @@ var transformData = require('./../core/transformData');
 var buildURL = require('./../helpers/buildURL');
 var parseHeaders = require('./../helpers/parseHeaders');
 var isURLSameOrigin = require('./../helpers/isURLSameOrigin');
+var createError = require('../core/createError');
 var btoa = (typeof window !== 'undefined' && window.btoa) || require('./../helpers/btoa');
 
 module.exports = function xhrAdapter(resolve, reject, config) {
@@ -82,7 +83,7 @@ module.exports = function xhrAdapter(resolve, reject, config) {
   request.onerror = function handleError() {
     // Real errors are hidden from us by the browser
     // onerror should only fire if it's a network error
-    reject(new Error('Network Error'));
+    reject(createError('Network Error', config));
 
     // Clean up request
     request = null;
@@ -90,10 +91,7 @@ module.exports = function xhrAdapter(resolve, reject, config) {
 
   // Handle timeout
   request.ontimeout = function handleTimeout() {
-    var err = new Error('timeout of ' + config.timeout + 'ms exceeded');
-    err.timeout = config.timeout;
-    err.code = 'ECONNABORTED';
-    reject(err);
+    reject(createError('timeout of ' + config.timeout + 'ms exceeded', config, 'ECONNABORTED'));
 
     // Clean up request
     request = null;

lib/core/createError.js

+'use strict';
+
+var enhanceError = require('./enhanceError');
+
+/**
+ * Create an Error with the specified message, config, and optional error code.
+ *
+ * @param {string} message The error message.
+ * @param {Object} config The config object.
+ * @param {string} [code] The error code (for example, 'ECONNABORTED').
+ * @returns {Error} The created error.
+ */
+module.exports = function createError(message, config, code) {
+  var error = new Error(message);
+  return enhanceError(error, config, code);
+};

lib/core/enhanceError.js

+'use strict';
+
+/**
+ * Update an Error with the specified config and optional error code.
+ *
+ * @param {Error} error The error to update.
+ * @param {Object} config The config object.
+ * @param {string} [code] The error code (for example, 'ECONNABORTED').
+ * @returns {Error} The error.
+ */
+module.exports = function enhanceError(error, config, code) {
+  error.config = config;
+  if (code) {
+    error.code = code;
+  }
+  return error;
+};

lib/core/settle.js

 'use strict';
 
+var createError = require('./createError');
+
 /**
  * Resolve or reject a Promise based on response status.
  *
@@ -13,6 +15,8 @@ module.exports = function settle(resolve, reject, response) {
   if (!response.status || !validateStatus || validateStatus(response.status)) {
     resolve(response);
   } else {
-    reject(response);
+    var error = createError('Request failed with status code ' + response.status, response.config);
+    error.response = response;
+    reject(error);
   }
 };

test/specs/core/createError.spec.js

+var createError = require('../../../lib/core/createError');
+
+describe('core::createError', function() {
+  it('should create an Error with message, config, and code', function() {
+    var error = createError('Boom!', { foo: 'bar' }, 'ESOMETHING');
+    expect(error instanceof Error).toBe(true);
+    expect(error.message).toBe('Boom!');
+    expect(error.config).toEqual({ foo: 'bar' });
+    expect(error.code).toBe('ESOMETHING');
+  });
+});

test/specs/core/enhanceError.spec.js

+var enhanceError = require('../../../lib/core/enhanceError');
+
+describe('core::enhanceError', function() {
+  it('should add config and code to error', function() {
+    var error = new Error('Boom!');
+    enhanceError(error, { foo: 'bar' }, 'ESOMETHING');
+    expect(error.config).toEqual({ foo: 'bar' });
+    expect(error.code).toBe('ESOMETHING');
+  });
+
+  it('should return error', function() {
+    var error = new Error('Boom!');
+    expect(enhanceError(error, { foo: 'bar' }, 'ESOMETHING')).toBe(error);
+  });
+});

test/specs/core/settle.spec.js

@@ -58,7 +58,12 @@ describe('core::settle', function() {
     };
     settle(resolve, reject, response);
     expect(resolve).not.toHaveBeenCalled();
-    expect(reject).toHaveBeenCalledWith(response);
+    expect(reject).toHaveBeenCalled();
+    var reason = reject.calls.first().args[0];
+    expect(reason instanceof Error).toBe(true);
+    expect(reason.message).toBe('Request failed with status code 500');
+    expect(reason.config).toBe(response.config);
+    expect(reason.response).toBe(response);
   });
 
   it('should pass status to validateStatus', function() {

test/specs/requests.spec.js

@@ -46,6 +46,10 @@ describe('requests', function () {
     var finish = function () {
       expect(resolveSpy).not.toHaveBeenCalled();
       expect(rejectSpy).toHaveBeenCalled();
+      var reason = rejectSpy.calls.first().args[0];
+      expect(reason instanceof Error).toBe(true);
+      expect(reason.config.method).toBe('get');
+      expect(reason.config.url).toBe('http://thisisnotaserver');
 
       done();
     };
@@ -68,6 +72,13 @@ describe('requests', function () {
       .then(function () {
         expect(resolveSpy).not.toHaveBeenCalled();
         expect(rejectSpy).toHaveBeenCalled();
+        var reason = rejectSpy.calls.first().args[0];
+        expect(reason instanceof Error).toBe(true);
+        expect(reason.message).toBe('Request failed with status code 500');
+        expect(reason.config.method).toBe('get');
+        expect(reason.config.url).toBe('/foo');
+        expect(reason.response.status).toBe(500);
+
         done();
       });
 

test/unit/adapters/http.js

@@ -25,8 +25,8 @@ module.exports = {
         timeout: 250
       }).then(function (res) {
         success = true;
-      }).catch(function (res) {
-        error = res;
+      }).catch(function (err) {
+        error = err;
         failure = true;
       });
 
@@ -189,8 +189,8 @@ module.exports = {
         maxContentLength: 2000
       }).then(function (res) {
         success = true;
-      }).catch(function (res) {
-        error = res;
+      }).catch(function (err) {
+        error = err;
         failure = true;
       });