Fix and add tests

lib/watchpack.js

@@ -26,7 +26,7 @@ function addWatchersToSet(watchers, set) {
 
 const stringOrRegexpToRegexp = ignored => {
 	if (ignored instanceof RegExp) {
-		return ignored;
+		return ignored.source;
 	}
 	const { source } = globToRegExp(ignored, { globstar: true, extended: true });
 	const matchingStart = source.slice(0, source.length - 1) + "(?:$|\\/)";

test/Watchpack.js

@@ -118,6 +118,32 @@ describe("Watchpack", function() {
 		});
 	});
 
+	it("should not watch a single ignored file (array with regexp and glob)", function(done) {
+		var w = new Watchpack({
+			aggregateTimeout: 300,
+			ignored: [/\/a$/, "**/b"]
+		});
+		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