Add a semicolon for IIFE workers to work (#3)

* Add a semicolon
IIFE's won't work without it

* Add a test for IIFE

Author: Alex Nozdriukhin

src/index.js

@@ -78,7 +78,7 @@ global.Worker = function Worker(url) {
 		.then( code => {
 			let vars = 'var self=this,global=self';
 			for (let k in scope) vars += `,${k}=self.${k}`;
-			getScopeVar = eval('(function() {'+vars+'\n'+code+'\nreturn function(__){return eval(__)}})').call(scope);
+			getScopeVar = eval('(function() {'+vars+';\n'+code+'\nreturn function(__){return eval(__)}})').call(scope);
 			let q = messageQueue;
 			messageQueue = null;
 			q.forEach(this.postMessage);

test/index.test.js

@@ -24,4 +24,14 @@ describe('jsdom-worker', () => {
 		await sleep(10);
 		expect(worker.onmessage).toHaveBeenCalledWith({ data: 'test' });
 	});
+
+	it('should work with IIFE', async () => {
+		const n = Math.random();
+		const code = `(function(n){ onmessage = e => { postMessage(n) } })(${n})`;
+		const worker = new Worker(URL.createObjectURL(new Blob([code])));
+		worker.onmessage = jest.fn();
+		worker.postMessage();
+		await sleep(10);
+		expect(worker.onmessage).toHaveBeenCalledWith({ data: n });
+	});
 });