ensure watcher receives dependencies again (#756)

Since #713 the API no longer emits 'dependencies' events. These are emitted
instead by the RunStatus, which can be obtained by listening to the 'test-run'
event on the API.

The watcher tests use a mocked API object which wasn't updated to reflect these
changes. Consequently dependency tracking was broken since #713 was merged.

This commit fixes the watcher and the corresponding tests. I've also added an
integration test which does not rely on mocking, helping us detect breakage
sooner.

lib/watcher.js

@@ -125,10 +125,12 @@ Watcher.prototype.trackTestDependencies = function (api, sources) {
 		return nodePath.relative(cwd, absPath);
 	};
 
-	api.on('dependencies', function (file, dependencies) {
+	api.on('test-run', function (runStatus) {
+		runStatus.on('dependencies', function (file, dependencies) {
 			var sourceDeps = dependencies.map(relative).filter(isSource);
 			self.updateTestDependencies(file, sourceDeps);
 		});
+	});
 };
 
 Watcher.prototype.updateTestDependencies = function (file, sources) {

test/cli.js

@@ -176,7 +176,7 @@ test('pkg-conf: cli takes precedence', function (t) {
 	});
 });
 
-test('watcher works', function (t) {
+test("watcher reruns test files when they changed", function (t) {
 	var killed = false;
 
 	var child = execCli(['--verbose', '--watch', 'test.js'], {dirname: 'fixture/watcher'}, function (err, stdout, stderr) {
@@ -209,6 +209,30 @@ test('watcher works', function (t) {
 });
 
 if (hasChokidar) {
+	test("watcher reruns test files when source dependencies change", function (t) {
+		var killed = false;
+
+		var child = execCli(['--verbose', '--watch', '--source=source.js', 'test-*.js'], {dirname: 'fixture/watcher/with-dependencies'}, function (err) {
+			t.ok(killed);
+			t.ifError(err);
+			t.end();
+		});
+
+		var buffer = '';
+		var passedFirst = false;
+		child.stderr.on('data', function (str) {
+			buffer += str;
+			if (/2 tests passed/.test(buffer) && !passedFirst) {
+				touch.sync(path.join(__dirname, 'fixture/watcher/with-dependencies/source.js'));
+				buffer = '';
+				passedFirst = true;
+			} else if (/1 test passed/.test(buffer) && !killed) {
+				child.kill();
+				killed = true;
+			}
+		});
+	});
+
 	test('`"tap": true` config is ignored when --watch is given', function (t) {
 		var killed = false;
 

test/fixture/watcher/with-dependencies/source.js

@@ -0,0 +1,2 @@
+'use strict';
+module.exports = true;

test/fixture/watcher/with-dependencies/test-1.js

@@ -0,0 +1,6 @@
+import test from '../../../../';
+import dependency from './source.js';
+
+test('works', t => {
+	t.truthy(dependency);
+});

test/fixture/watcher/with-dependencies/test-2.js

@@ -0,0 +1,5 @@
+import test from '../../../../';
+
+test('works', t => {
+	t.pass();
+});

test/watcher.js

@@ -812,15 +812,23 @@ group('chokidar is installed', function (beforeEach, test, group) {
 
 	group('tracks test dependencies', function (beforeEach, test) {
 		var apiEmitter;
+		var runStatus;
+		var runStatusEmitter;
 		beforeEach(function () {
 			apiEmitter = new EventEmitter();
 			api.on = function (event, fn) {
 				apiEmitter.on(event, fn);
 			};
+			runStatusEmitter = new EventEmitter();
+			runStatus = {
+				on: function (event, fn) {
+					runStatusEmitter.on(event, fn);
+				}
+			};
 		});
 
 		var emitDependencies = function (file, dependencies) {
-			apiEmitter.emit('dependencies', file, dependencies);
+			runStatusEmitter.emit('dependencies', file, dependencies);
 		};
 
 		var seed = function (sources) {
@@ -832,8 +840,13 @@ group('chokidar is installed', function (beforeEach, test, group) {
 			}));
 
 			var watcher = start(sources);
-			emitDependencies(path.join('test', '1.js'), [path.resolve('dep-1.js'), path.resolve('dep-3.js')]);
-			emitDependencies(path.join('test', '2.js'), [path.resolve('dep-2.js'), path.resolve('dep-3.js')]);
+			var files = [path.join('test', '1.js'), path.join('test', '2.js')];
+			var absFiles = files.map(function (relFile) {
+				return path.resolve(relFile);
+			});
+			apiEmitter.emit('test-run', runStatus, absFiles);
+			emitDependencies(files[0], [path.resolve('dep-1.js'), path.resolve('dep-3.js')]);
+			emitDependencies(files[1], [path.resolve('dep-2.js'), path.resolve('dep-3.js')]);
 
 			done();
 			api.run.returns(new Promise(function () {}));