fix issue with return next()

Author: dougmoscrop

lib/handler.js

@@ -2,9 +2,9 @@
 
 async function dispatch(middleware, state, i = 0) {
 	const fn = middleware[i] || Function.prototype;
-	const next = (err, context, event) => {
+	const next = async (err, context, event) => {
 		if (err) {
-			return Promise.reject(err);
+			throw err;
 		}
 
 		if (context !== undefined) {
@@ -15,7 +15,7 @@ async function dispatch(middleware, state, i = 0) {
 			state.event = event;
 		}
 
-		return dispatch(middleware, state, i + 1);
+		await dispatch(middleware, state, i + 1);
 	};
 
 	const result = await fn(state.event, state.context, next);

test/lambda-handler-tests.js

@@ -212,7 +212,7 @@ describe('handler', function() {
 				});
 		});
 
-		it('middleware can override result after next()', function() {
+		it('middleware can override result after await next()', function() {
 			const stub = sinon.stub().returns('foo');
 			const fixture = lambdaHandler()
 				.use(async (event, context, next) => {
@@ -228,6 +228,24 @@ describe('handler', function() {
 				});
 		});
 
+		it('middleware can override result after return next()', function() {
+			const stub = sinon.stub().returns('foo');
+			const fixture = lambdaHandler()
+				.use(async (event, context, next) => {
+					return next()
+						.then(() => {
+							return 'bar';
+						});
+				})
+				.use(stub);
+
+			return fixture(testEvent, testContext)
+				.then(result => {
+					expect(result).to.equal('bar');
+					expect(stub.calledOnce).to.be.true;
+				});
+		});
+
 		it('can do things around next() without affecting result', function() {
 			const obj = {};
 			let after = false;
@@ -245,6 +263,20 @@ describe('handler', function() {
 				});
 		});
 
+		it('can have middleware return next() without affecting result value', function() {
+			const obj = {};
+			const fixture = lambdaHandler()
+				.use((event, context, next) => {
+					return next();
+				})
+				.use(() => obj);
+
+			return fixture(testEvent, testContext)
+				.then(result => {
+					expect(result).to.equal(obj);
+				});
+		});
+
 		it('has expected execution order', function() {
 			const order = [];
 			const fixture = lambdaHandler()