check if watchers work as expected

Author: sokra

test/Assumption.js

@@ -9,6 +9,10 @@ var TestHelper = require("./helpers/TestHelper");
 var fixtures = path.join(__dirname, "fixtures");
 var testHelper = new TestHelper(fixtures);
 
+const IS_OSX = require("os").platform() === "darwin";
+const IS_WIN = require("os").platform() === "win32";
+const SUPPORTS_RECURSIVE_WATCHING = IS_OSX || IS_WIN;
+
 describe("Assumption", function() {
 	this.timeout(10000);
 	var watcherToClose = null;
@@ -145,6 +149,76 @@ describe("Assumption", function() {
 		}
 	});
 
+	if (SUPPORTS_RECURSIVE_WATCHING) {
+		it("should have a file system with correct mtime behavior (fs.watch recursive)", function(done) {
+			this.timeout(20000);
+			testHelper.file("a");
+			var i = 60;
+			var count = 60;
+			var before;
+			var after;
+			var minDiffBefore = +Infinity;
+			var maxDiffBefore = -Infinity;
+			var sumDiffBefore = 0;
+			var minDiffAfter = +Infinity;
+			var maxDiffAfter = -Infinity;
+			var sumDiffAfter = 0;
+			var watcher = (watcherToClose = fs.watch(fixtures, { recursive: true }));
+			testHelper.tick(100, function() {
+				watcher.on("change", function(type, filename) {
+					const s = fs.statSync(path.join(fixtures, filename));
+					if (before && after) {
+						var diffBefore = +s.mtime - before;
+						if (diffBefore < minDiffBefore) minDiffBefore = diffBefore;
+						if (diffBefore > maxDiffBefore) maxDiffBefore = diffBefore;
+						sumDiffBefore += diffBefore;
+						var diffAfter = +s.mtime - after;
+						if (diffAfter < minDiffAfter) minDiffAfter = diffAfter;
+						if (diffAfter > maxDiffAfter) maxDiffAfter = diffAfter;
+						sumDiffAfter += diffAfter;
+						before = after = undefined;
+						if (i-- === 0) {
+							afterMeasure();
+						} else {
+							testHelper.tick(100, checkMtime);
+						}
+					}
+				});
+				testHelper.tick(100, checkMtime);
+			});
+
+			function checkMtime() {
+				before = Date.now();
+				testHelper.file("a");
+				after = Date.now();
+			}
+
+			function afterMeasure() {
+				console.log(
+					"mtime fs.watch({ recursive: true }) accuracy (before): [" +
+						minDiffBefore +
+						" ; " +
+						maxDiffBefore +
+						"] avg " +
+						Math.round(sumDiffBefore / count)
+				);
+				console.log(
+					"mtime fs.watch({ recursive: true }) accuracy (after): [" +
+						minDiffAfter +
+						" ; " +
+						maxDiffAfter +
+						"] avg " +
+						Math.round(sumDiffAfter / count)
+				);
+				minDiffBefore.should.be.aboveOrEqual(-2000);
+				maxDiffBefore.should.be.below(2000);
+				minDiffAfter.should.be.aboveOrEqual(-2000);
+				maxDiffAfter.should.be.below(2000);
+				done();
+			}
+		});
+	}
+
 	it("should not fire events in subdirectories", function(done) {
 		testHelper.dir("watch-test-directory");
 		testHelper.tick(500, () => {
@@ -166,7 +240,77 @@ describe("Assumption", function() {
 		});
 	});
 
-	if (require("os").platform() !== "darwin") {
+	if (SUPPORTS_RECURSIVE_WATCHING) {
+		it("should fire events in subdirectories (recursive)", function(done) {
+			testHelper.dir("watch-test-directory");
+			testHelper.file("watch-test-directory/watch-test-file");
+			testHelper.file("watch-test-directory/existing-file");
+			testHelper.tick(500, () => {
+				var watcher = (watcherToClose = fs.watch(fixtures, {
+					recursive: true
+				}));
+				const events = [];
+				watcher.once("change", () => {
+					testHelper.tick(1000, function() {
+						events.should.matchAny(/watch-test-directory[/\\]watch-test-file/);
+						done();
+					});
+				});
+				watcher.on("change", function(type, filename) {
+					events.push(filename);
+				});
+				watcher.on("error", function(err) {
+					done(err);
+					done = function() {};
+				});
+				testHelper.tick(500, function() {
+					testHelper.file("watch-test-directory/watch-test-file");
+				});
+			});
+		});
+
+		it("should allow to create/close/create recursive watchers", function(done) {
+			testHelper.dir("watch-test-directory");
+			testHelper.file("watch-test-directory/watch-test-file");
+			testHelper.file("watch-test-directory/existing-file");
+			testHelper.tick(500, () => {
+				watcherToClose = fs.watch(fixtures, {
+					recursive: true
+				});
+				watcherToClose.close();
+				watcherToClose = fs.watch(fixtures, {
+					recursive: true
+				});
+				watcherToClose.close();
+				watcherToClose = fs.watch(fixtures, {
+					recursive: true
+				});
+				watcherToClose.close();
+				var watcher = (watcherToClose = fs.watch(fixtures, {
+					recursive: true
+				}));
+				const events = [];
+				watcher.once("change", () => {
+					testHelper.tick(1000, function() {
+						events.should.matchAny(/watch-test-directory[/\\]watch-test-file/);
+						done();
+					});
+				});
+				watcher.on("change", function(type, filename) {
+					events.push(filename);
+				});
+				watcher.on("error", function(err) {
+					done(err);
+					done = function() {};
+				});
+				testHelper.tick(500, function() {
+					testHelper.file("watch-test-directory/watch-test-file");
+				});
+			});
+		});
+	}
+
+	if (!IS_OSX) {
 		it("should detect removed directory", function(done) {
 			testHelper.dir("watch-test-dir");
 			testHelper.tick(() => {