Allow simple regex to be passed in array

lib/watchpack.js

@@ -24,18 +24,25 @@ function addWatchersToSet(watchers, set) {
 	}
 }
 
-const stringToRegexp = ignored => {
-	const source = globToRegExp(ignored, { globstar: true, extended: true })
-		.source;
+const stringOrRegexpToRegexp = ignored => {
+	if (ignored instanceof RegExp) {
+		if (ignored.flags !== "") {
+			throw new Error(
+				`Invalid option for 'ignored', regex in list does not support flags ${ignored}`
+			);
+		}
+		return ignored.source;
+	}
+	const { source } = globToRegExp(ignored, { globstar: true, extended: true });
 	const matchingStart = source.slice(0, source.length - 1) + "(?:$|\\/)";
 	return matchingStart;
 };
 
 const ignoredToRegexp = ignored => {
 	if (Array.isArray(ignored)) {
-		return new RegExp(ignored.map(i => stringToRegexp(i)).join("|"));
+		return new RegExp(ignored.map(i => stringOrRegexpToRegexp(i)).join("|"));
 	} else if (typeof ignored === "string") {
-		return new RegExp(stringToRegexp(ignored));
+		return new RegExp(stringOrRegexpToRegexp(ignored));
 	} else if (ignored instanceof RegExp) {
 		return ignored;
 	} else if (ignored) {

test/Watchpack.js

@@ -14,6 +14,16 @@ describe("Watchpack", function() {
 	beforeEach(testHelper.before);
 	afterEach(testHelper.after);
 
+	it("should throw on invalid ignore options", function() {
+		try {
+		var w = new Watchpack({
+			ignored: [/\/a$/i]
+		});
+		} catch(e) {
+			e.message.should.startWith("Invalid");
+		}
+	});
+
 	it("should watch a single file", function(done) {
 		var w = new Watchpack({
 			aggregateTimeout: 1000
@@ -118,6 +128,32 @@ 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