Add fail fast support

A new config option `bail` is available. Setting this to a truthy value
will cause all subsequent tests (in all suites) after a failing test to
be skipped.

Resolves #413

lib/Suite.js

@@ -11,6 +11,10 @@ define([
 		this.reporterManager && this.reporterManager.emit('newSuite', this);
 	}
 
+	// BAIL_REASON needs to be a string so that Intern can tell when a remote has bailed during unit tests so that it
+	// can skip functional tests.
+	var BAIL_REASON = 'bailed';
+
 	Suite.prototype = {
 		constructor: Suite,
 		name: null,
@@ -22,6 +26,7 @@ define([
 		teardown: null,
 		error: null,
 		timeElapsed: null,
+		_bail: null,
 		_grep: null,
 		_remote: null,
 		_environmentType: null,
@@ -33,6 +38,17 @@ define([
 		 */
 		publishAfterSetup: false,
 
+		/**
+		 * A flag used to indicate whether a test run shoudl stop after a failed test.
+		 */
+		get bail() {
+			return this._bail || (this.parent && this.parent.bail);
+		},
+
+		set bail(value) {
+			this._bail = value;
+		},
+
 		/**
 		 * A regular expression used to filter, by test ID, which tests are run.
 		 */
@@ -291,8 +307,8 @@ define([
 						throw reason;
 					});
 
-					function next() {
-						var test = tests[i++];
+					function next(test) {
+						test = tests[i++];
 
 						if (!test) {
 							firstError ? reject(firstError) : resolve();
@@ -350,7 +366,23 @@ define([
 								});
 						}
 
-						current.then(next);
+						current.then(function () {
+							function skipRestOfSuite() {
+								self.skipped = self.skipped != null ? self.skipped : BAIL_REASON;
+							}
+
+							// If the test was a suite and the suite was skipped due to bailing, skip the rest of this
+							// suite
+							if (test.tests && test.skipped === BAIL_REASON) {
+								skipRestOfSuite();
+							}
+							// If the test errored and bail mode is enabled, skip the rest of this suite
+							else if (test.error && self.bail) {
+								skipRestOfSuite();
+							}
+
+							next();
+						});
 					}
 
 					next();

lib/executors/Client.js

@@ -50,7 +50,8 @@ define([
 				grep: config.grep,
 				sessionId: config.sessionId,
 				timeout: config.defaultTimeout,
-				reporterManager: this.reporterManager
+				reporterManager: this.reporterManager,
+				bail: config.bail
 			});
 
 			this.suites = [ suite ];

lib/executors/Runner.js

@@ -184,6 +184,7 @@ define([
 					reporterManager: reporterManager,
 					publishAfterSetup: true,
 					grep: config.grep,
+					bail: config.bail,
 					timeout: config.defaultTimeout,
 					setup: function () {
 						return util.retry(function () {

tests/unit/lib/Suite.js

@@ -644,6 +644,65 @@ define([
 			}));
 		},
 
+		'Suite#run bail': function () {
+			var dfd = this.async(5000);
+			var suite = createSuite({
+				bail: true
+			});
+			var testsRun = [];
+			var fooTest = new Test({
+				name: 'foo',
+				parent: suite,
+				test: function () {
+					testsRun.push(this);
+				}
+			});
+			var barSuite = createSuite({
+				name: 'bar',
+				parent: suite,
+				tests: [
+					new Test({
+						name: 'foo',
+						test: function () {
+							testsRun.push(this);
+							// Fail this test; everything after this should not run
+							throw new Error('fail');
+						}
+					}),
+					new Test({
+						name: 'baz',
+						test: function () {
+							testsRun.push(this);
+						}
+					})
+				]
+			});
+			var foodTest = new Test({
+				name: 'food',
+				parent: suite,
+				test: function () {
+					testsRun.push(this);
+				}
+			});
+
+			var teardownRan = false;
+			barSuite.teardown = function () {
+				teardownRan = true;
+			};
+
+			suite.tests.push(fooTest);
+			suite.tests.push(barSuite);
+			suite.tests.push(foodTest);
+
+			suite.run().then(dfd.callback(function () {
+				assert.deepEqual(testsRun, [ fooTest, barSuite.tests[0] ],
+					'Only tests before failing test should have run');
+				assert.isTrue(teardownRan, 'teardown should have run for bailing suite');
+			}, function () {
+				dfd.reject(new assert.AssertionError('Suite should not fail'));
+			}));
+		},
+
 		'Suite#run skip': function () {
 			var dfd = this.async(5000);
 			var suite = createSuite();