Extended sequence utility

no issue

- support promise and none promise tasks
- helpful if you create an array of operations and not all of the operations/tasks are async
- `response instanceof Promise` does not work for all cases e.g. some usages return a transaction/bookshelf chain

core/server/lib/promise/sequence.js

@@ -1,16 +1,25 @@
-var Promise = require('bluebird');
+const Promise = require('bluebird');
 
 /**
  * expects an array of functions returning a promise
  */
 function sequence(tasks /* Any Arguments */) {
-    var args = Array.prototype.slice.call(arguments, 1);
+    const args = Array.prototype.slice.call(arguments, 1);
 
     return Promise.reduce(tasks, function (results, task) {
-        return task.apply(this, args).then(function (result) {
-            results.push(result);
-            return results;
-        });
+        const response = task.apply(this, args);
+
+        if (response && response.then) {
+            return response.then(function (result) {
+                results.push(result);
+                return results;
+            });
+        } else {
+            return Promise.resolve().then(() => {
+                results.push(response);
+                return results;
+            });
+        }
     }, []);
 }
 

core/test/unit/lib/promise/sequence_spec.js

@@ -0,0 +1,29 @@
+const should = require('should');
+const sinon = require('sinon');
+const Promise = require('bluebird');
+const sequence = require('../../../../server/lib/promise/sequence');
+const sandbox = sinon.sandbox.create();
+
+describe('Unit: lib/promise/sequence', function () {
+    afterEach(function () {
+        sandbox.restore();
+    });
+
+    it('mixed tasks: promise and none promise', function () {
+        const tasks = [
+            function a() {
+                return Promise.resolve('hello');
+            },
+            function b() {
+                return 'from';
+            },
+            function c() {
+                return Promise.resolve('chio');
+            },
+        ];
+        return sequence(tasks)
+            .then(function (result) {
+                result.should.eql(['hello','from', 'chio']);
+            });
+    });
+});