Merge pull request #174 from strongloop/fix/booted-event-asynchrony

executor: move "booted" and cb() to the next tick

lib/executor.js

@@ -43,7 +43,12 @@ module.exports = function execute(app, instructions, callback) {
     function(done) {
       enableAnonymousSwagger(app, instructions);
       done();
-    }], function(err) {
+    },
+    // Ensure both the "booted" event and the callback are always called
+    // in the next tick of the even loop.
+    // See http://blog.izs.me/post/59142742143/designing-apis-for-asynchrony
+    process.nextTick,
+    ], function(err) {
       app.booting = false;
 
       if (err) return callback(err);

test/executor.test.js

@@ -66,15 +66,15 @@ describe('executor', function() {
       });
     });
 
-    it('should emit the `booted` event', function(done) {
+    it('should emit the `booted` event in the next tick', function(done) {
+      boot.execute(app, dummyInstructions, function(err) {
+        expect(err).to.be.undefined();
+      });
       app.on('booted', function() {
         // This test fails with a timeout when the `booted` event has not been
         // emitted correctly
         done();
       });
-      boot.execute(app, dummyInstructions, function(err) {
-        expect(err).to.be.undefined();
-      });
     });
 
     it('should work when called synchronously', function() {