Add async handler support for nodejs8.10 runtime (dherault#398)

Author: domaslasauskas

package.json

@@ -44,6 +44,7 @@
     "David Bunker (https://github.com/dbunker)",
     "demetriusnunes (https://github.com/demetriusnunes)",
     "DJCrabhat (https://github.com/djcrabhat)",
+    "Domas Lasauskas (https://github.com/domaslasauskas)",
     "Echo Nolan (https://github.com/enolan)",
     "Egor Kislitsyn (https://github.com/minibikini)",
     "Elliott Spira (https://github.com/em0ney)",

src/index.js

@@ -779,7 +779,7 @@ class Offline {
               const x = handler(event, lambdaContext, lambdaContext.done);
 
               // Promise support
-              if (serviceRuntime === 'babel' && !this.requests[requestId].done) {
+              if ((serviceRuntime === 'nodejs8.10' || serviceRuntime === 'babel') && !this.requests[requestId].done) {
                 if (x && typeof x.then === 'function' && typeof x.catch === 'function') x.then(lambdaContext.succeed).catch(lambdaContext.fail);
                 else if (x instanceof Error) lambdaContext.fail(x);
               }

test/integration/offline.js

@@ -387,7 +387,6 @@ describe('Offline', () => {
         else {
           cb('JSON body was mangled');
         }
-        
       }).toObject();
       done();
     });
@@ -421,4 +420,35 @@ describe('Offline', () => {
       });
     });
   });
+
+  context('aws runtime nodejs8.10', () => {
+    const serverless = { service: { provider: {
+      name: 'aws',
+      stage: 'dev',
+      region: 'us-east-1',
+      runtime: 'nodejs8.10',
+    } } };
+
+    it('should support handler returning Promise', done => {
+      const offLine = new OffLineBuilder(new ServerlessBuilder(serverless))
+        .addFunctionHTTP('index', {
+          path: 'index',
+          method: 'GET',
+        }, (event, context) => Promise.resolve({
+          statusCode: 200,
+          body: JSON.stringify({ message: 'Hello World' }),
+        })).toObject();
+
+      offLine.inject({
+        method: 'GET',
+        url: '/index',
+        payload: { data: 'input' },
+      }, res => {
+        expect(res.headers).to.have.property('content-type', 'application/json');
+        expect(res.statusCode).to.eq(200);
+        expect(res.payload).to.eq('{"message":"Hello World"}');
+        done();
+      });
+    });
+  });
 });