Fix hanging promise when callback from Napa to Node (#141)

lib/zone/zone-impl.ts

@@ -42,6 +42,21 @@ class Result implements zone.Result{
      private _value: any;
 };
 
+declare var __in_napa: boolean;
+
+/// <summary> Helper function to workaround possible delay in Promise resolve/reject when working with Node event loop.
+/// See https://github.com/audreyt/node-webworker-threads/issues/123#issuecomment-254019552
+/// </summary>
+function runImmediately(func : () => void) {
+    if (typeof __in_napa === 'undefined') {
+        // In node.
+        setImmediate(func);
+    } else  {
+        // In napa workers.
+        func();
+    }
+}
+
 /// <summary> Zone consists of Napa isolates. </summary>
 export class ZoneImpl implements zone.Zone {
     private _nativeZone: any;
@@ -63,11 +78,13 @@ export class ZoneImpl implements zone.Zone {
 
         return new Promise<void>((resolve, reject) => {
             this._nativeZone.broadcast(source, (resultCode: number) => {
-                if (resultCode === 0) {
-                    resolve();
-                } else {
-                    reject("broadcast failed with result code: " + resultCode);
-                }
+                runImmediately(() => {
+                    if (resultCode === 0) {
+                        resolve();
+                    } else {
+                        reject("broadcast failed with result code: " + resultCode);
+                    }
+                });
             });
         });
     }
@@ -77,13 +94,15 @@ export class ZoneImpl implements zone.Zone {
         
         return new Promise<zone.Result>((resolve, reject) => {
             this._nativeZone.execute(spec, (result: any) => {
-                if (result.code === 0) {
-                    resolve(new Result(
-                        result.returnValue,
-                        transport.createTransportContext(true, result.contextHandle)));
-                } else {
-                    reject(result.errorMessage);
-                }
+                runImmediately(() => {
+                    if (result.code === 0) {
+                        resolve(new Result(
+                            result.returnValue,
+                            transport.createTransportContext(true, result.contextHandle)));
+                    } else {
+                        reject(result.errorMessage);
+                    }
+                })
             });
         });
     }

test/memory-test.ts

@@ -6,7 +6,6 @@ import * as assert from 'assert';
 import * as path from 'path';
 
 describe('napajs/memory', function() {
-    this.timeout(0);
     let napaZone = napa.zone.create('zone5');
 
     describe('Handle', () => {

test/module-test.ts

@@ -8,7 +8,6 @@ import * as path from "path";
 type Zone = napa.zone.Zone;
 
 describe('napajs/module', function () {
-    this.timeout(0);
     let napaZone = napa.zone.create('module-tests-zone', { workers: 1 });
 
     describe('load', function () {

test/store-test.ts

@@ -6,8 +6,6 @@ import * as assert from 'assert';
 import * as path from 'path';
 
 describe('napajs/store', function () {
-    this.timeout(0);
-
     let napaZone = napa.zone.create('zone6');
     let store1 = napa.store.create('store1');
     it('@node: store.create - succeed', () => {

test/zone-test.ts

@@ -18,10 +18,6 @@ function shouldFail<T>(func: () => Promise<T>) {
 }
 
 describe('napajs/zone', function () {
-    // disable timeouts. 
-    // promise.then is always fired after mocha test timeout.
-    this.timeout(0);
-
     let napaZone1: Zone = napa.zone.create('napa-zone1');
     let napaZone2: Zone = napa.zone.create('napa-zone2');
     let napaLibPath: string = path.resolve(__dirname, '../lib');
@@ -32,11 +28,12 @@ describe('napajs/zone', function () {
             assert.strictEqual(napaZone1.id, 'napa-zone1');
         });
 
+        // This case may be slow as the first hit of napa zone execute API, so we clear timeout.
         it('@napa: default settings', async () => {
             // Zone should be destroyed when going out of scope.
             let result = await napaZone1.execute(`${napaLibPath}/zone`, 'create', ['new-zone']);
             assert.equal(result.value.id, "new-zone");
-        });
+        }).timeout(0);
 
         it('@node: zone id already exists', () => {
             assert.throws(() => { napa.zone.create('napa-zone1'); });