feat(apimock): automatic fallbacks

ApiMock can now activate automatically on request errors. So it’ll try
to access the API and if it fails then it will try to do a rerouted
mock request instead. The flag is `auto` and can be set globally in
browser url `?apiMock=auto` or locally on $http request (`$http.get({
url: ‘…’, apiMock: ‘auto’ })`).

app/scripts/angular-apimock.js

@@ -48,6 +48,7 @@ angular.module('apiMock', [])
   var apiPath = '/api';
   var $location;
 	var $q;
+	var fallbacks = [];
 
 	function determineMock(obj) {
 		switch (typeof obj) {
@@ -57,6 +58,9 @@ angular.module('apiMock', [])
 			case 'number':
 				return !obj ? false : obj;
 
+//			case 'string':
+//				return obj === 'auto' ? true : !!obj;
+
 			default:
 				return !!obj;
 		}
@@ -106,13 +110,33 @@ angular.module('apiMock', [])
     return !!(mock && this._isApiPath(req));
   };
 
+	p.shouldAutoMock = function (req) {
+		return $location.search('apiMock') === 'auto' || req.apiMock === 'auto';
+	};
+
 	p.doMock = function (req) {
 		if (req && typeof req.apiMock === 'number') {
 			return httpStatusResponse(req);
 		}
 		return mockDataResponse(req);
 	};
 
+	p.prepare = function (req) {
+		fallbacks.push(req);
+	};
+
+	p.remove = function (res) {
+		var found = false;
+		angular.forEach(fallbacks, function (fallback, index) {
+			if (fallback.method === res.method && fallback.url === res.url) {
+				found = true;
+				fallbacks.removeAt(index);
+			}
+		});
+
+		return found;
+	};
+
   p._isApiPath = function (req) {
     return req && req.url.indexOf(config.apiPath) === 0;
   };
@@ -154,11 +178,29 @@ angular.module('apiMock', [])
    `apiMock` to determine if a mock should be done, then do the actual mocking.
 */
   this.request = function (req) {
+		if (req && apiMock.shouldAutoMock(req)) {
+			apiMock.prepare(req);
+		}
+		else
     if (req && apiMock.shouldMock(req)) {
       req = apiMock.doMock(req);
     }
 
 		// Return the request or promise.
     return req || $q.when(req);
   };
+
+	this.response = function (res) {
+		apiMock.remove(res);
+
+		return res || $q.when(res);
+	};
+
+	this.responseError = function (rejection) {
+		if (apiMock.remove(rejection)) {
+			return apiMock.doMock(rejection);
+		}
+
+		return $q.reject(rejection);
+	};
 });

test/spec/services/angular-apimock.js

@@ -360,6 +360,59 @@ describe('Service: apiMock', function () {
 
 			$httpBackend.flush();
 		});
+
+		it('should automatically mock when request fails, with global flag auto', function (done) {
+			// Set global flag: auto
+			$location.search('apiMock', 'auto');
+
+			// Don't include override
+			var mockRequest = {
+				url: '/api/people/pokemon',
+				method: 'GET'
+			};
+
+			// Do a call, and expect it to recover from fail.
+			$httpBackend.when('GET', '/api/people/pokemon').respond(404);
+			$httpBackend.when('GET', '/mock_data/people/pokemon.get.json').respond(200);
+			$http(mockRequest)
+				.success(function() {
+					done();
+				})
+				.error(function() {
+					expect(true).to.be.false; // Todo: How to fail the test if this happens?
+					done();
+				});
+
+			$httpBackend.flush();
+		});
+
+		it('cant automatically mock request failure if the URL is an invalid API url', function (done) {
+			// Set global flag: auto
+			$location.search('apiMock', 'auto');
+
+			// Don't include override, but use an URL that doesn't pass the isApiPath test.
+			var mockRequest = {
+				url: '/something/people/pokemon',
+				method: 'GET'
+			};
+
+			// Verify the API path is invalid.
+			expect(apiMock._isApiPath(mockRequest)).to.be.false;
+
+			// Do a call, and expect it to fail.
+			$httpBackend.when('GET', '/something/people/pokemon').respond(404);
+			$http(mockRequest)
+				.success(function() {
+					expect(true).to.be.false; // Todo: How to fail the test if this happens?
+					done();
+				})
+				.error(function(data, status) {
+					expect(status).to.equal(404);
+					done();
+				});
+
+			$httpBackend.flush();
+		});
 	});
 
 });