Merge pull request #27 from Financial-Times/matth/minor-refactors

Minor internal refactors

src/evented-queue.js

@@ -3,27 +3,27 @@ const EventEmitter = require('events');
 class EventedQueue extends EventEmitter {
 	constructor() {
 		super();
-		this.queue = new Set();
+		this.waiting = new Set();
 	}
 
 	add(item) {
-		this.queue.add(item);
+		this.waiting.add(item);
 		this.emit('add', item);
 		return this;
 	}
 
 	delete(item) {
-		this.queue.delete(item);
+		this.waiting.delete(item);
 		this.emit('delete', item);
 		return this;
 	}
 
-	waitFor(items = []) {
+	waitBehind(items = []) {
 		return new Promise((resolve) => {
 			const callback = () => {
-				const itemsRunning = items.some((item) => this.queue.has(item));
+				const itemsWaiting = items.some((item) => this.waiting.has(item));
 
-				if (!itemsRunning) {
+				if (!itemsWaiting) {
 					this.removeListener('delete', callback);
 					resolve();
 				}

src/run-parallel.js

@@ -9,22 +9,21 @@ module.exports = (tasks = [], concurrency = 1, preserveOrder = false) => {
 	logger.info(`Executing up to ${concurrency} tasks at a time`);
 
 	return Promise.all(
-		tasks.map(({ pkg, apply }) => {
+		tasks.map(async ({ pkg, apply }) => {
 			queue.add(pkg.name);
 
-			return semaphore
-				.acquire()
-				.then(() => {
-					// wait for any dependencies still in the queue to finish
-					return preserveOrder ? queue.waitFor(pkg.allDependencies) : null;
-				})
-				.then(() => {
-					return apply();
-				})
-				.then(() => {
-					queue.delete(pkg.name);
-					return semaphore.release();
-				});
+			await semaphore.acquire();
+
+			// wait for any dependencies still in the queue to finish
+			if (preserveOrder) {
+				await queue.waitBehind(pkg.allDependencies);
+			}
+
+			await apply();
+
+			queue.delete(pkg.name);
+
+			semaphore.release();
 		})
 	);
 };

test/src/evented-queue.spec.js

@@ -10,7 +10,7 @@ describe('src/evented-queue', () => {
 	describe('#add', () => {
 		it('adds the given item to the queue', () => {
 			instance.add('foo');
-			expect(instance.queue.size).toEqual(1);
+			expect(instance.waiting.size).toEqual(1);
 		});
 
 		it('emits an event when items are added to the queue', (done) => {
@@ -25,10 +25,10 @@ describe('src/evented-queue', () => {
 	describe('#delete', () => {
 		it('removes the given item to the queue', () => {
 			instance.add('foo');
-			expect(instance.queue.size).toEqual(1);
+			expect(instance.waiting.size).toEqual(1);
 
 			instance.delete('foo');
-			expect(instance.queue.size).toEqual(0);
+			expect(instance.waiting.size).toEqual(0);
 		});
 
 		it('emits an event when items are removed from the queue', (done) => {
@@ -42,15 +42,15 @@ describe('src/evented-queue', () => {
 		});
 	});
 
-	describe('#waitFor', () => {
+	describe('#waitBehind', () => {
 		it('resolves when the queue no longer contains any of the given items', (done) => {
 			instance
 				.add('foo')
 				.add('bar')
 				.add('baz');
 
-			instance.waitFor(['foo', 'bar', 'baz']).then(() => {
-				expect(instance.queue.size).toEqual(0);
+			instance.waitBehind(['foo', 'bar', 'baz']).then(() => {
+				expect(instance.waiting.size).toEqual(0);
 				done();
 			});