Watchpack.js

/*globals describe it beforeEach afterEach */
"use strict";

require("should");
var path = require("path");
var TestHelper = require("./helpers/TestHelper");
var Watchpack = require("../lib/watchpack");

var fixtures = path.join(__dirname, "fixtures");
var testHelper = new TestHelper(fixtures);

describe("Watchpack", function() {
	this.timeout(10000);
	beforeEach(testHelper.before);
	afterEach(testHelper.after);

	it("should watch a single file", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = 0;
		w.on("change", function(file) {
			file.should.be.eql(path.join(fixtures, "a"));
			changeEvents++;
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "a")]);
			changeEvents.should.be.greaterThan(0);
			w.close();
			done();
		});
		w.watch([path.join(fixtures, "a")], []);
		testHelper.tick(function() {
			testHelper.file("a");
		});
	});

	it("should aggregate changes while paused", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		testHelper.file("a");
		testHelper.file("b");
		w.watch([path.join(fixtures, "a"), path.join(fixtures, "b")], []);
		testHelper.tick(function() {
			w.pause();
			w.on("change", function(file) {
				throw new Error("should not be emitted");
			});
			w.on("aggregated", function(changes) {
				throw new Error("should not be emitted");
			});
			testHelper.tick(function() {
				testHelper.file("a");
				testHelper.remove("b");
				testHelper.file("b");
				testHelper.remove("a");
				testHelper.tick(function() {
					const { changes, removals } = w.getAggregated();
					Array.from(changes).should.be.eql([path.join(fixtures, "b")]);
					Array.from(removals).should.be.eql([path.join(fixtures, "a")]);
					w.close();
					done();
				});
			});
		});
	});

	it("should not watch a single ignored file (glob)", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 300,
			ignored: "**/a"
		});
		var changeEvents = 0;
		var aggregatedEvents = 0;
		w.on("change", () => {
			changeEvents++;
		});
		w.on("aggregated", () => {
			aggregatedEvents++;
		});
		w.watch([path.join(fixtures, "a")], []);
		testHelper.tick(() => {
			testHelper.file("a");
			testHelper.tick(1000, () => {
				changeEvents.should.be.eql(0);
				aggregatedEvents.should.be.eql(0);
				testHelper.getNumberOfWatchers().should.be.eql(0);
				w.close();
				done();
			});
		});
	});

	it("should not watch a single ignored file (regexp)", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 300,
			ignored: /\/a$/
		});
		var changeEvents = 0;
		var aggregatedEvents = 0;
		w.on("change", () => {
			changeEvents++;
		});
		w.on("aggregated", () => {
			aggregatedEvents++;
		});
		w.watch([path.join(fixtures, "a")], []);
		testHelper.tick(() => {
			testHelper.file("a");
			testHelper.tick(1000, () => {
				changeEvents.should.be.eql(0);
				aggregatedEvents.should.be.eql(0);
				testHelper.getNumberOfWatchers().should.be.eql(0);
				w.close();
				done();
			});
		});
	});

	it("should not watch a single ignored file (function)", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 300,
			ignored: entry => entry.includes("a")
		});
		var changeEvents = 0;
		var aggregatedEvents = 0;
		w.on("change", () => {
			changeEvents++;
		});
		w.on("aggregated", () => {
			aggregatedEvents++;
		});
		w.watch([path.join(fixtures, "a")], []);
		testHelper.tick(() => {
			testHelper.file("a");
			testHelper.tick(1000, () => {
				changeEvents.should.be.eql(0);
				aggregatedEvents.should.be.eql(0);
				testHelper.getNumberOfWatchers().should.be.eql(0);
				w.close();
				done();
			});
		});
	});

	it("should watch multiple files", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes)
				.sort()
				.should.be.eql([path.join(fixtures, "a"), path.join(fixtures, "b")]);
			changeEvents.should.be.eql([
				path.join(fixtures, "a"),
				path.join(fixtures, "b"),
				path.join(fixtures, "a"),
				path.join(fixtures, "b"),
				path.join(fixtures, "a")
			]);
			Object.keys(w.getTimes())
				.sort()
				.should.be.eql([path.join(fixtures, "a"), path.join(fixtures, "b")]);
			w.close();
			done();
		});
		w.watch([path.join(fixtures, "a"), path.join(fixtures, "b")], []);
		testHelper.tick(400, function() {
			testHelper.file("a");
			testHelper.tick(400, function() {
				testHelper.file("b");
				testHelper.tick(400, function() {
					testHelper.file("a");
					testHelper.tick(400, function() {
						testHelper.file("b");
						testHelper.tick(400, function() {
							testHelper.file("a");
						});
					});
				});
			});
		});
	});

	it("should watch a directory", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir")]);
			changeEvents.should.be.eql([path.join(fixtures, "dir", "a")]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.tick(200, function() {
			w.watch([], [path.join(fixtures, "dir")]);
			testHelper.tick(200, function() {
				testHelper.file(path.join("dir", "a"));
			});
		});
	});

	it("should not watch an ignored directory", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 300,
			ignored: ["**/dir"]
		});
		var changeEvents = 0;
		var aggregatedEvents = 0;
		w.on("change", () => {
			changeEvents++;
		});
		w.on("aggregated", () => {
			aggregatedEvents++;
		});
		testHelper.dir("dir");
		testHelper.tick(200, function() {
			w.watch([], [path.join(fixtures, "dir")]);
			testHelper.tick(200, function() {
				testHelper.file(path.join("dir", "a"));
				testHelper.tick(1000, function() {
					changeEvents.should.be.eql(0);
					aggregatedEvents.should.be.eql(0);
					testHelper.getNumberOfWatchers().should.be.eql(0);
					w.close();
					done();
				});
			});
		});
	});

	it("should not watch an ignored file in a directory", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 300,
			ignored: ["**/a"]
		});
		var changeEvents = 0;
		var aggregatedEvents = 0;
		w.on("change", () => {
			changeEvents++;
		});
		w.on("aggregated", () => {
			aggregatedEvents++;
		});
		testHelper.dir("dir");
		testHelper.tick(200, function() {
			w.watch([], [path.join(fixtures, "dir")]);
			testHelper.tick(200, function() {
				testHelper.file(path.join("dir", "a"));
				testHelper.tick(1000, function() {
					changeEvents.should.be.eql(0);
					aggregatedEvents.should.be.eql(0);
					w.close();
					done();
				});
			});
		});
	});

	it("should watch a file then a directory", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes, removals) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir")]);
			Array.from(removals).should.be.eql([]);
			changeEvents.should.be.eql([path.join(fixtures, "dir", "a")]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.dir(path.join("dir", "subdir"));
		testHelper.file(path.join("dir", "a"));
		testHelper.tick(400, function() {
			w.watch([path.join(fixtures, "dir", "a")], []);
			testHelper.tick(function() {
				w.watch([], [path.join(fixtures, "dir")]);
				testHelper.tick(function() {
					testHelper.file(path.join("dir", "a"));
				});
			});
		});
	});

	it("should watch a directory (delete file)", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir")]);
			changeEvents.should.be.eql([path.join(fixtures, "dir", "a")]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.file(path.join("dir", "a"));
		testHelper.tick(function() {
			w.watch([], [path.join(fixtures, "dir")]);
			testHelper.tick(function() {
				testHelper.remove(path.join("dir", "a"));
			});
		});
	});

	it("should watch a directory (delete and recreate file)", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir")]);
			changeEvents.should.be.eql([
				path.join(fixtures, "dir", "a"),
				path.join(fixtures, "dir", "b"),
				path.join(fixtures, "dir", "a")
			]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.file(path.join("dir", "a"));
		testHelper.tick(function() {
			w.watch([], [path.join(fixtures, "dir")]);
			testHelper.tick(function() {
				testHelper.remove(path.join("dir", "a"));
				testHelper.tick(function() {
					testHelper.file(path.join("dir", "b"));
					testHelper.tick(500, function() {
						testHelper.file(path.join("dir", "a"));
					});
				});
			});
		});
	});

	it("should watch a missing directory", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir", "sub")]);
			changeEvents.should.be.eql([path.join(fixtures, "dir", "sub")]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.tick(function() {
			w.watch({ missing: [path.join(fixtures, "dir", "sub")] });
			testHelper.tick(function() {
				testHelper.dir(path.join("dir", "sub"));
			});
		});
	});

	it("should watch a directory (add directory)", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir")]);
			changeEvents.should.be.eql([path.join(fixtures, "dir", "sub")]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.tick(function() {
			w.watch([], [path.join(fixtures, "dir")]);
			testHelper.tick(function() {
				testHelper.dir(path.join("dir", "sub"));
			});
		});
	});

	it("should watch a directory (delete directory)", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir")]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.dir(path.join("dir", "sub"));
		testHelper.file(path.join("dir", "sub", "a"));
		testHelper.tick(function() {
			w.watch([], [path.join(fixtures, "dir")]);
			testHelper.tick(function() {
				testHelper.remove(path.join("dir", "sub"));
			});
		});
	});

	it("should watch a directory (delete, restore and change directory)", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes, removals) {
			Array.from(changes).should.be.eql([
				path.join(fixtures, "dir", "sub", "a")
			]);
			Array.from(removals).should.be.eql([]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.dir(path.join("dir", "sub"));
		testHelper.file(path.join("dir", "sub", "a"));
		testHelper.tick(function() {
			w.watch([path.join(fixtures, "dir", "sub", "a")], []);
			testHelper.tick(function() {
				testHelper.remove(path.join("dir", "sub"));
				testHelper.tick(function() {
					testHelper.dir(path.join("dir", "sub"));
					testHelper.file(path.join("dir", "sub", "a"));
				});
			});
		});
	});

	it("should watch a directory (delete directory2)", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir")]);
			changeEvents.should.be.eql([path.join(fixtures, "dir", "sub")]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.dir(path.join("dir", "sub"));
		testHelper.tick(function() {
			w.watch([], [path.join(fixtures, "dir")]);
			testHelper.tick(function() {
				testHelper.remove(path.join("dir", "sub"));
			});
		});
	});

	it("should watch already watched directory", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir")]);
			changeEvents.should.be.eql([path.join(fixtures, "dir", "a")]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.file(path.join("dir", "a"));
		testHelper.tick(400, function() {
			w.watch([path.join(fixtures, "dir", "a")], []);
			testHelper.tick(1000, function() {
				w.watch([], [path.join(fixtures, "dir")]);
				testHelper.tick(400, function() {
					testHelper.remove(path.join("dir", "a"));
				});
			});
		});
	});

	it("should watch file in a sub directory", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir")]);
			changeEvents.should.be.eql([path.join(fixtures, "dir", "sub", "a")]);
			var times = w.getTimeInfoEntries();
			const dir = times.get(path.join(fixtures, "dir"));
			const sub = times.get(path.join(fixtures, "dir", "sub"));
			const a = times.get(path.join(fixtures, "dir", "sub", "a"));
			dir.should.be.type("object");
			dir.should.have.property("safeTime");
			sub.safeTime.should.be.aboveOrEqual(a.safeTime);
			dir.safeTime.should.be.aboveOrEqual(sub.safeTime);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.dir(path.join("dir", "sub"));
		testHelper.tick(function() {
			w.watch([], [path.join(fixtures, "dir")]);
			testHelper.tick(function() {
				testHelper.file(path.join("dir", "sub", "a"));
			});
		});
	});

	it("should watch file in a sub directory (passed in maps)", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir")]);
			changeEvents.should.be.eql([path.join(fixtures, "dir", "sub", "a")]);
			const files = new Map();
			const directories = new Map();
			w.collectTimeInfoEntries(files, directories);
			const dir = directories.get(path.join(fixtures, "dir"));
			const dirAsFile = files.get(path.join(fixtures, "dir"));
			const sub = directories.get(path.join(fixtures, "dir", "sub"));
			const subAsFile = files.get(path.join(fixtures, "dir", "sub"));
			const a = files.get(path.join(fixtures, "dir", "sub", "a"));
			dir.should.be.type("object");
			dir.should.have.property("safeTime");
			dirAsFile.should.be.type("object");
			dirAsFile.should.not.have.property("safeTime");
			sub.should.be.type("object");
			sub.should.have.property("safeTime");
			subAsFile.should.be.type("object");
			subAsFile.should.not.have.property("safeTime");
			a.should.be.type("object");
			a.should.have.property("safeTime");
			a.should.have.property("timestamp");
			sub.safeTime.should.be.aboveOrEqual(a.safeTime);
			dir.safeTime.should.be.aboveOrEqual(sub.safeTime);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.dir(path.join("dir", "sub"));
		testHelper.dir(path.join("dir", "sub2"));
		testHelper.tick(function() {
			w.watch([], [path.join(fixtures, "dir")]);
			testHelper.tick(function() {
				testHelper.file(path.join("dir", "sub", "a"));
			});
		});
	});

	it("should watch 2 files in a not-existing directory", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		w.on("aggregated", function(changes) {
			Array.from(changes)
				.sort()
				.should.be.eql([
					path.join(fixtures, "dir", "sub", "a"),
					path.join(fixtures, "dir", "sub", "b")
				]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		w.watch(
			[
				path.join(fixtures, "dir", "sub", "a"),
				path.join(fixtures, "dir", "sub", "b")
			],
			[]
		);
		testHelper.tick(function() {
			testHelper.dir(path.join("dir", "sub"));
			testHelper.file(path.join("dir", "sub", "a"));
			testHelper.file(path.join("dir", "sub", "b"));
		});
	});

	it("should watch file in a sub sub directory", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir")]);
			changeEvents.should.be.eql([
				path.join(fixtures, "dir", "sub", "sub", "a")
			]);
			Object.keys(w.getTimes())
				.sort()
				.should.be.eql([
					path.join(fixtures, "dir"),
					path.join(fixtures, "dir", "sub"),
					path.join(fixtures, "dir", "sub", "sub"),
					path.join(fixtures, "dir", "sub", "sub", "a")
				]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.dir(path.join("dir", "sub"));
		testHelper.dir(path.join("dir", "sub", "sub"));
		testHelper.tick(2000, function() {
			w.watch([], [path.join(fixtures, "dir")], Date.now());
			testHelper.tick(function() {
				testHelper.file(path.join("dir", "sub", "sub", "a"));
			});
		});
	});

	it("should watch file in a directory that contains special glob characters", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = [];
		w.on("change", function(file) {
			if (changeEvents[changeEvents.length - 1] === file) return;
			changeEvents.push(file);
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "dir")]);
			changeEvents.should.be.eql([path.join(fixtures, "dir", "sub()", "a")]);
			var times = w.getTimeInfoEntries();
			const dir = times.get(path.join(fixtures, "dir"));
			const sub = times.get(path.join(fixtures, "dir", "sub()"));
			const a = times.get(path.join(fixtures, "dir", "sub()", "a"));
			sub.safeTime.should.be.aboveOrEqual(a.safeTime);
			dir.safeTime.should.be.aboveOrEqual(sub.safeTime);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.dir(path.join("dir", "sub()"));
		testHelper.tick(2000, function() {
			w.watch([], [path.join(fixtures, "dir")]);
			testHelper.tick(function() {
				testHelper.file(path.join("dir", "sub()", "a"));
			});
		});
	});

	it("should detect a single change to future timestamps", function(done) {
		const options = {
			aggregateTimeout: 1000
		};
		var w = new Watchpack(options);
		var w2 = new Watchpack(options);
		w.on("change", function() {
			throw new Error("should not report change event");
		});
		w.on("aggregated", function() {
			throw new Error("should not report aggregated event");
		});
		testHelper.file("a");
		testHelper.tick(400, function() {
			w2.watch([path.join(fixtures, "a")], [], Date.now());
			testHelper.tick(1000, function() {
				// wait for initial scan
				testHelper.mtime("a", Date.now() + 1000000);
				testHelper.tick(400, function() {
					w.watch([path.join(fixtures, "a")], [], Date.now());
					testHelper.tick(1000, function() {
						w2.close();
						w.close();
						done();
					});
				});
			});
		});
	});

	it("should create different watchers for different options", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var w2 = new Watchpack({
			aggregateTimeout: 1000
		});
		testHelper.file("a");
		testHelper.tick(400, function() {
			w.watch([path.join(fixtures, "a")], [], Date.now());
			w2.watch([path.join(fixtures, "a")], [], Date.now());
			testHelper.tick(1000, function() {
				testHelper.file("a");
				testHelper.tick(400, function() {
					testHelper.file("a");
					testHelper.tick(1000, function() {
						w2.close();
						w.close();
						done();
					});
				});
			});
		});
	});

	it("should detect a past change to a file (timestamp)", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var changeEvents = 0;
		w.on("change", function(file) {
			file.should.be.eql(path.join(fixtures, "a"));
			changeEvents++;
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "a")]);
			changeEvents.should.be.greaterThan(0);
			w.close();
			done();
		});
		var startTime = Date.now();
		testHelper.tick(function() {
			testHelper.file("a");
			testHelper.tick(function() {
				w.watch([path.join(fixtures, "a")], [], startTime);
			});
		});
	});

	it("should not detect a past change to a file (watched)", function(done) {
		var w2 = new Watchpack();
		var w = new Watchpack();
		w.on("change", function() {
			throw new Error("Should not be detected");
		});
		testHelper.tick(function() {
			testHelper.file("b");
			w2.watch([path.join(fixtures, "b")], []);
			testHelper.tick(1000, function() {
				// wait for stable state
				testHelper.file("a");
				testHelper.tick(1000, function() {
					var startTime = Date.now();
					testHelper.tick(400, function() {
						w.watch([path.join(fixtures, "a")], [], startTime);
						testHelper.tick(1000, function() {
							w.close();
							w2.close();
							done();
						});
					});
				});
			});
		});
	});

	it("should detect a past change to a file (watched)", function(done) {
		var w2 = new Watchpack();
		var w = new Watchpack();
		var changeEvents = 0;
		w.on("change", function(file) {
			file.should.be.eql(path.join(fixtures, "a"));
			changeEvents++;
		});
		w.on("aggregated", function(changes) {
			Array.from(changes).should.be.eql([path.join(fixtures, "a")]);
			changeEvents.should.be.eql(1);
			w.close();
			w2.close();
			done();
		});
		testHelper.tick(function() {
			testHelper.file("b");
			w2.watch([path.join(fixtures, "b")], []);
			testHelper.tick(function() {
				var startTime = Date.now();
				testHelper.tick(function() {
					testHelper.file("a");
					testHelper.tick(400, function() {
						w.watch([path.join(fixtures, "a")], [], startTime);
					});
				});
			});
		});
	});

	it("should watch a single file removal", function(done) {
		testHelper.file("a");
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		var removeEvents = 0;
		w.on("remove", function(file) {
			file.should.be.eql(path.join(fixtures, "a"));
			removeEvents++;
		});
		w.on("aggregated", function(changes, removals) {
			Array.from(removals).should.be.eql([path.join(fixtures, "a")]);
			removeEvents.should.be.eql(1);
			w.close();
			done();
		});
		testHelper.tick(400, function() {
			w.watch([path.join(fixtures, "a")], []);
			testHelper.tick(function() {
				testHelper.remove("a");
			});
		});
	});

	it("should watch multiple file removals", function(done) {
		var step = 0;
		testHelper.file("a");
		testHelper.file("b");
		var w = new Watchpack({
			aggregateTimeout: 3000
		});
		var removeEvents = [];
		w.on("remove", function(file) {
			if (removeEvents[removeEvents.length - 1] === file) return;
			removeEvents.push(file);
		});
		w.on("aggregated", function(changes, removals) {
			step.should.be.eql(6);
			Array.from(removals)
				.sort()
				.should.be.eql([path.join(fixtures, "a"), path.join(fixtures, "b")]);
			if (!+process.env.WATCHPACK_POLLING) {
				removeEvents.should.be.eql([
					path.join(fixtures, "a"),
					path.join(fixtures, "b"),
					path.join(fixtures, "a"),
					path.join(fixtures, "b")
				]);
			}
			Object.keys(w.getTimes())
				.sort()
				.should.be.eql([path.join(fixtures, "a"), path.join(fixtures, "b")]);
			w.close();
			done();
		});
		testHelper.tick(400, function() {
			w.watch([path.join(fixtures, "a"), path.join(fixtures, "b")], []);
			step = 1;
			testHelper.tick(1000, function() {
				testHelper.remove("a");
				step = 2;
				testHelper.tick(function() {
					testHelper.remove("b");
					step = 3;
					testHelper.tick(1000, function() {
						testHelper.file("a");
						testHelper.file("b");
						step = 4;
						testHelper.tick(1000, function() {
							testHelper.remove("a");
							step = 5;
							testHelper.tick(function() {
								testHelper.remove("b");
								step = 6;
							});
						});
					});
				});
			});
		});
	});

	it("should not report changes in initial scan when no start time is provided", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 100
		});
		w.on("aggregated", () => {
			done(new Error("should not fire"));
		});
		testHelper.dir("dir");
		testHelper.dir("dir/b");
		testHelper.dir("dir/b/sub");
		testHelper.file("dir/b/sub/file");
		testHelper.dir("dir/b/sub/sub");
		testHelper.file("dir/b/sub/sub/file");
		testHelper.file("dir/b/file");
		testHelper.file("dir/a");
		testHelper.tick(1000, () => {
			w.watch({
				directories: [path.join(fixtures, "dir", "b", "sub")]
			});
			testHelper.tick(2000, () => {
				// no event fired
				w.watch({
					files: [path.join(fixtures, "dir", "a")],
					directories: [
						path.join(fixtures, "dir", "b", "sub"),
						path.join(fixtures, "dir", "b")
					],
					missing: [path.join(fixtures, "dir", "c")]
				});
				testHelper.tick(2000, () => {
					// no event fired
					w.close();
					done();
				});
			});
		});
	});

	it("should not report changes in initial scan when start time is provided", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 100
		});
		w.on("aggregated", () => {
			done(new Error("should not fire"));
		});
		testHelper.dir("dir");
		testHelper.dir("dir/b");
		testHelper.dir("dir/b/sub");
		testHelper.file("dir/b/sub/file");
		testHelper.dir("dir/b/sub/sub");
		testHelper.file("dir/b/sub/sub/file");
		testHelper.file("dir/b/file");
		testHelper.file("dir/a");
		testHelper.tick(1000, () => {
			w.watch({
				directories: [path.join(fixtures, "dir", "b", "sub")],
				startTime: Date.now()
			});
			testHelper.tick(2000, () => {
				// no event fired
				w.watch({
					files: [path.join(fixtures, "dir", "a")],
					directories: [
						path.join(fixtures, "dir", "b", "sub"),
						path.join(fixtures, "dir", "b")
					],
					missing: [path.join(fixtures, "dir", "c")],
					startTime: Date.now()
				});
				testHelper.tick(2000, () => {
					// no event fired
					w.close();
					done();
				});
			});
		});
	});

	it("should not report changes to a folder watched as file when items are added", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 100
		});
		w.on("aggregated", () => {
			done(new Error("should not fire"));
		});
		testHelper.dir("dir");
		testHelper.file("dir/a");
		testHelper.tick(1000, () => {
			testHelper.file("dir/b");
			w.watch({
				files: [path.join(fixtures, "dir")],
				startTime: Date.now()
			});
			testHelper.tick(1000, () => {
				testHelper.file("dir/c");
				testHelper.tick(1000, () => {
					// no event fired
					w.close();
					done();
				});
			});
		});
	});

	it("should report removal of file and directory if it is missing in initial scan", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		w.on("aggregated", function(changes, removals) {
			Array.from(changes).should.be.eql([]);
			Array.from(removals)
				.sort()
				.should.be.eql([
					path.join(fixtures, "dir", "a"),
					path.join(fixtures, "dir", "b")
				]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.tick(() => {
			w.watch({
				files: [path.join(fixtures, "dir", "a")],
				directories: [path.join(fixtures, "dir", "b")],
				missing: [path.join(fixtures, "dir", "c")]
			});
		});
	});

	it("should report removal of file and directory if parent directory is missing in initial scan", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		w.on("aggregated", function(changes, removals) {
			Array.from(changes).should.be.eql([]);
			Array.from(removals)
				.sort()
				.should.be.eql([
					path.join(fixtures, "dir", "a"),
					path.join(fixtures, "dir", "b")
				]);
			w.close();
			done();
		});
		testHelper.tick(() => {
			w.watch({
				files: [path.join(fixtures, "dir", "a")],
				directories: [path.join(fixtures, "dir", "b")],
				missing: [path.join(fixtures, "dir", "c")]
			});
		});
	});

	it("should not detect file reading as change, but atomic file writes", done => {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		w.on("aggregated", function(changes, removals) {
			Array.from(changes)
				.sort()
				.should.be.eql([
					path.join(fixtures, "dir", "b"),
					path.join(fixtures, "dir", "c")
				]);
			Array.from(removals).should.be.eql([]);
			w.close();
			done();
		});
		testHelper.dir("dir");
		testHelper.file(path.join("dir", "a"));
		testHelper.file(path.join("dir", "b"));
		testHelper.file(path.join("dir", "c"));
		testHelper.tick(1000, () => {
			w.watch({
				files: [
					path.join(fixtures, "dir", "a"),
					path.join(fixtures, "dir", "b"),
					path.join(fixtures, "dir", "c")
				]
			});
			testHelper.tick(1000, () => {
				testHelper.accessFile(path.join("dir", "a"));
				testHelper.fileAtomic(path.join("dir", "b"));
				testHelper.file(path.join("dir", "c"));
			});
		});
	});

	it("should allow to reuse watchers when watch is called again", function(done) {
		var w = new Watchpack({
			aggregateTimeout: 1000
		});
		w.on("aggregated", () => {
			done(new Error("should not fire"));
		});
		testHelper.dir("dir");
		testHelper.dir("dir/b");
		testHelper.dir("dir/b/sub");
		testHelper.file("dir/b/sub/file");
		testHelper.file("dir/b/file");
		testHelper.dir("dir/b1");
		testHelper.dir("dir/b1/sub");
		testHelper.file("dir/b1/sub/file");
		testHelper.file("dir/b1/file");
		testHelper.dir("dir/b2");
		testHelper.dir("dir/b2/sub");
		testHelper.file("dir/b2/sub/file");
		testHelper.file("dir/b2/file");
		testHelper.file("dir/a");
		testHelper.file("dir/a1");
		testHelper.file("dir/a2");
		testHelper.tick(() => {
			w.watch({
				files: [
					path.join(fixtures, "dir", "a"),
					path.join(fixtures, "dir", "a1")
				],
				directories: [
					path.join(fixtures, "dir", "b"),
					path.join(fixtures, "dir", "b1")
				],
				missing: [
					path.join(fixtures, "dir", "c"),
					path.join(fixtures, "dir", "c1")
				]
			});
			testHelper.tick(() => {
				w.watch({
					files: [
						path.join(fixtures, "dir", "a"),
						path.join(fixtures, "dir", "a2")
					],
					directories: [
						path.join(fixtures, "dir", "b"),
						path.join(fixtures, "dir", "b2")
					],
					missing: [
						path.join(fixtures, "dir", "c"),
						path.join(fixtures, "dir", "c2")
					]
				});
				testHelper.file("dir/b1/sub/file");
				testHelper.file("dir/a1");
				testHelper.file("dir/c1");
				testHelper.tick(2000, () => {
					// no event fired
					w.close();
					done();
				});
			});
		});
	});

	let symlinksSupported = false;
	try {
		const fs = require("fs");
		fs.symlinkSync("helpers", path.join(__dirname, "fixtures"), "dir");
		fs.unlinkSync(path.join(__dirname, "fixtures"));
		symlinksSupported = true;
	} catch (e) {
		// ignore
	}

	if (symlinksSupported) {
		describe("symlinks", () => {
			beforeEach(done => {
				testHelper.dir("a");
				testHelper.dir(path.join("a", "b"));
				testHelper.file(path.join("a", "b", "c"));
				testHelper.file(path.join("a", "b", "d"));
				testHelper.symlinkDir("link", "a");
				testHelper.symlinkDir(path.join("a", "link"), "b");
				testHelper.symlinkFile(path.join("a", "b", "link"), "c");
				testHelper.symlinkFile(path.join("a", "b", "link2"), "link");
				testHelper.symlinkFile("link2", "link/link/link2");

				testHelper.tick(1000, done);
			});

			function expectWatchEvent(files, dirs, callback, ready) {
				var w = new Watchpack({
					aggregateTimeout: 500,
					followSymlinks: true
				});

				w.watch([].concat(files), [].concat(dirs), Date.now());

				let active = false;
				let closed = false;

				w.on("aggregated", changes => {
					w.close();
					closed = true;
					if (!active) throw new Error("Events are not expected yet");
					callback(changes);
				});

				testHelper.tick(1000, () => {
					if (closed) return;
					active = true;
					ready();
				});
			}

			it("should detect a change to the original file", function(done) {
				expectWatchEvent(
					path.join(fixtures, "link2"),
					[],
					changes => {
						Array.from(changes).should.be.eql([path.join(fixtures, "link2")]);
						done();
					},
					() => {
						testHelper.file(path.join("a", "b", "c"));
					}
				);
			});

			it("should detect a change to the direct symlink", function(done) {
				expectWatchEvent(
					path.join(fixtures, "link2"),
					[],
					changes => {
						Array.from(changes).should.be.eql([path.join(fixtures, "link2")]);
						done();
					},
					() => {
						testHelper.unlink("link2");
						testHelper.symlinkFile("link2", path.join("a", "b", "d"));
					}
				);
			});

			it("should detect a change to the double symlink", function(done) {
				expectWatchEvent(
					path.join(fixtures, "link2"),
					[],
					changes => {
						Array.from(changes).should.be.eql([path.join(fixtures, "link2")]);
						done();
					},
					() => {
						testHelper.unlink(path.join("a", "b", "link2"));
						testHelper.symlinkFile(path.join("a", "b", "link2"), "d");
					}
				);
			});

			it("should detect a change to the directory symlink", function(done) {
				expectWatchEvent(
					path.join(fixtures, "link2"),
					[],
					changes => {
						Array.from(changes).should.be.eql([path.join(fixtures, "link2")]);
						done();
					},
					() => {
						testHelper.unlink(path.join("a", "link"));
						testHelper.symlinkDir(path.join("a", "link"), path.join("b", "d"));
					}
				);
			});

			it("should detect a file change in a watched symlinked directory", function(done) {
				expectWatchEvent(
					[],
					path.join(fixtures, "link"),
					changes => {
						Array.from(changes).should.be.eql([path.join(fixtures, "link")]);
						done();
					},
					() => {
						testHelper.file(path.join("a", "b", "c"));
					}
				);
			});

			it("should detect a symlink file change in a watched symlinked directory", function(done) {
				expectWatchEvent(
					[],
					path.join(fixtures, "link"),
					changes => {
						Array.from(changes).should.be.eql([path.join(fixtures, "link")]);
						done();
					},
					() => {
						testHelper.unlink(path.join("a", "b", "link2"));
						testHelper.symlinkFile(path.join("a", "b", "link2"), "d");
					}
				);
			});

			it("should detect a symlink dir change in a watched symlinked directory", function(done) {
				expectWatchEvent(
					[],
					path.join(fixtures, "link"),
					changes => {
						Array.from(changes).should.be.eql([path.join(fixtures, "link")]);
						done();
					},
					() => {
						testHelper.unlink(path.join("a", "link"));
						testHelper.symlinkDir(path.join("a", "link"), path.join("b", "d"));
					}
				);
			});
		});
	} else {
		it("symlinks");
	}
});