Fix case renames not marking previous casing as missing in time entries

lib/DirectoryWatcher.js

@@ -64,6 +64,8 @@ class DirectoryWatcher extends EventEmitter {
 		// timestamp is a value that should be compared with another timestamp (mtime)
 		/** @type {Map<string, { safeTime: number, timestamp: number }} */
 		this.files = new Map();
+		/** @type {Map<string, number>} */
+		this.filesWithoutCase = new Map();
 		this.directories = new Map();
 		this.lastWatchEvent = 0;
 		this.initialScan = true;
@@ -154,8 +156,15 @@ class DirectoryWatcher extends EventEmitter {
 		const oldFile = this.files.get(itemPath);
 		if (oldFile) {
 			this.files.delete(itemPath);
+			const key = withoutCase(itemPath);
+			const count = this.filesWithoutCase.get(key) - 1;
+			if (count <= 0) {
+				this.filesWithoutCase.delete(key);
+				this.forEachWatcher(itemPath, w => w.emit("remove", type));
+			} else {
+				this.filesWithoutCase.set(key, count);
+			}
 
-			this.forEachWatcher(itemPath, w => w.emit("remove", type));
 			if (!initial) {
 				this.forEachWatcher(this.path, w =>
 					w.emit("change", itemPath, null, type)
@@ -198,6 +207,18 @@ class DirectoryWatcher extends EventEmitter {
 		this._cachedTimeInfoEntries = undefined;
 
 		if (!old) {
+			const key = withoutCase(filePath);
+			const count = this.filesWithoutCase.get(key);
+			this.filesWithoutCase.set(key, (count || 0) + 1);
+			if (count !== undefined) {
+				// There is already a file with case-insenstive-equal name
+				// On a case-insenstive filesystem we may miss the renaming
+				// when only casing is changed.
+				// To be sure that our information is correct
+				// we trigger a rescan here
+				this.doScan(false);
+			}
+
 			this.forEachWatcher(filePath, w => {
 				if (!initial || w.checkStartTime(safeTime, initial)) {
 					w.emit("change", mtime, type);

test/Casing.js

@@ -44,5 +44,75 @@ if (fsIsCaseInsensitive) {
 				testHelper.file("A");
 			});
 		});
+
+		it("should mark as missing on changing filename casing (dir watch)", function(done) {
+			var w = new Watchpack({
+				aggregateTimeout: 1000
+			});
+			var dir = "case-rename";
+			var testFile = path.join(dir, "hello.txt");
+			var testFileRename = path.join(dir, "hEllO.txt");
+			testHelper.dir(dir);
+			testHelper.file(testFile);
+
+			w.on("aggregated", function(changes, removals) {
+				const files = w.getTimeInfoEntries();
+				w.close();
+
+				changes.has(path.join(fixtures, dir)).should.be.eql(true);
+
+				for (const file of files.keys()) {
+					if (file.endsWith("hello.txt")) {
+						return done(new Error(`Renamed file was still in timeInfoEntries`));
+					}
+				}
+				return done();
+			});
+
+			testHelper.tick(function() {
+				w.watch([], [path.join(fixtures, "case-rename")]);
+
+				testHelper.tick(function() {
+					testHelper.rename(testFile, testFileRename);
+				});
+			});
+		});
+
+		it("should mark as missing on changing filename casing (file watch)", function(done) {
+			var w = new Watchpack({
+				aggregateTimeout: 1000
+			});
+			var dir = "case-rename";
+			var testFile = path.join(dir, "hello.txt");
+			var testFileRename = path.join(dir, "hEllO.txt");
+			testHelper.dir(dir);
+			testHelper.file(testFile);
+
+			w.on("aggregated", function(changes, removals) {
+				const files = w.getTimeInfoEntries();
+				w.close();
+
+				changes.has(path.join(fixtures, testFileRename)).should.be.eql(true);
+				removals.has(path.join(fixtures, testFileRename)).should.be.eql(false);
+
+				for (const file of files.keys()) {
+					if (file.endsWith("hello.txt") && files.get(file)) {
+						return done(new Error(`Renamed file was still in timeInfoEntries`));
+					}
+				}
+				return done();
+			});
+
+			testHelper.tick(function() {
+				w.watch({
+					files: [path.join(fixtures, testFile)],
+					missing: [path.join(fixtures, testFileRename)]
+				});
+
+				testHelper.tick(function() {
+					testHelper.rename(testFile, testFileRename);
+				});
+			});
+		});
 	});
 }

test/helpers/TestHelper.js

@@ -68,6 +68,10 @@ TestHelper.prototype.dir = function dir(name) {
 	fs.mkdirSync(path.join(this.testdir, name));
 };
 
+TestHelper.prototype.rename = function rename(orig, dest) {
+	fs.renameSync(path.join(this.testdir, orig), path.join(this.testdir, dest));
+};
+
 TestHelper.prototype.file = function file(name) {
 	fs.writeFileSync(path.join(this.testdir, name), Math.random() + "", "utf-8");
 };