Fix triggering of queued 'fail' methods on the request. Example:

model.save().fail( function() {
    // Should be triggered when the request fails
}

backbone_tastypie/static/js/backbone-tastypie.js

@@ -18,8 +18,8 @@
 		if ( method === 'create' ) {
 			var dfd = new $.Deferred();
 
-			var success = options.success;
-			dfd.done( success );
+			// Set up 'success' handling
+			dfd.done( options.success );
 			options.success = function( resp, status, xhr ) {
 				// If create is successful but doesn't return a response, fire an extra GET.
 				// Otherwise, resolve the deferred (which triggers the original 'success' callbacks).
@@ -36,6 +36,11 @@
 				}
 			};
 
+			// Set up 'error' handling
+			dfd.fail( options.error );
+			options.error = dfd.reject;
+
+			// Make the request, make it accessibly by assigning it to the 'request' property on the deferred 
 			dfd.request = Backbone.oldSync( method, model, options );
 			return dfd;
 		}

test/tests.js

@@ -94,7 +94,7 @@ $(document).ready(function() {
 		});
 
 		test( "Success callbacks are triggered, receive proper parameters", function() {
-			expect( 4 );
+			expect( 6 );
 
 			var emptyResponse = '';
 			var response = { id: 1, 'resource_uri': '/animal/1/' };
@@ -108,18 +108,47 @@ $(document).ready(function() {
 			// Request with a response
 			var animal = new Animal( { species: 'Turtle' } );
 			var dfd = animal.save( null, { success: successCallback } );
+			// Add another 'success' callback
+			dfd.done( function() {
+					ok( true, "Done triggered" );
+				});
 
 				// Do the server's job
 				dfd.request.success( response, 'created', xhr );
 
 			// Request without a response right away, response in second request
 			animal = new Animal( { species: 'Lion' } );
 			dfd = animal.save( null, { success: successCallback } );
+			// Add another 'success' callback
+			dfd.done( function() {
+					ok( true, "Done triggered" );
+				});
 
 				// Do the server's job
 				var secondRequest = dfd.request.success( emptyResponse, 'created', xhr );
 				secondRequest.success( response, 'get', { status: 200 } );
 		});
+
+		test( "Error callbacks are triggered, receive proper parameters", function() {
+			expect( 2 );
+
+			var xhr = { status: 404 };
+
+			var errorCallback = function( model, resp, options ) {
+					equals( resp.status, 404 );
+				};
+
+			// Request with a response
+			var animal = new Animal( { species: 'Turtle' } );
+			var dfd = animal.save( null, { error: errorCallback } );
+			// Add another 'error' callback
+			dfd.fail( function() {
+					ok( true, "Fail triggered" );
+				});
+
+				// Do the server's job
+				dfd.request.error( xhr, 'error', 'Not found' );
+		});
 
 
 	module("Model url building", { setup: initObjects } );