add spec for HeadlessJsTaskSupport (#24907)

Summary:
part of #24875

## Changelog

[General] [Added] - add TM spec for HeadlessJsTaskSupport
Pull Request resolved: https://github.com/facebook/react-native/pull/24907

Reviewed By: RSNara

Differential Revision: D15425720

Pulled By: fkgozali

fbshipit-source-id: 2e904f265a68066918bae4f6f95494ad77654598

Libraries/ReactNative/AppRegistry.js

@@ -11,7 +11,6 @@
 
 const BatchedBridge = require('../BatchedBridge/BatchedBridge');
 const BugReporting = require('../BugReporting/BugReporting');
-const NativeModules = require('../BatchedBridge/NativeModules');
 const ReactNative = require('../Renderer/shims/ReactNative');
 const SceneTracker = require('../Utilities/SceneTracker');
 
@@ -21,6 +20,8 @@ const renderApplication = require('./renderApplication');
 const createPerformanceLogger = require('../Utilities/createPerformanceLogger');
 import type {IPerformanceLogger} from '../Utilities/createPerformanceLogger';
 
+import NativeHeadlessJsTaskSupport from './NativeHeadlessJsTaskSupport';
+
 type Task = (taskData: any) => Promise<void>;
 type TaskProvider = () => Task;
 type TaskCanceller = () => void;
@@ -261,16 +262,22 @@ const AppRegistry = {
     const taskProvider = taskProviders.get(taskKey);
     if (!taskProvider) {
       console.warn(`No task registered for key ${taskKey}`);
-      NativeModules.HeadlessJsTaskSupport.notifyTaskFinished(taskId);
+      if (NativeHeadlessJsTaskSupport) {
+        NativeHeadlessJsTaskSupport.notifyTaskFinished(taskId);
+      }
       return;
     }
     taskProvider()(data)
-      .then(() =>
+      .then(() => {
-        NativeModules.HeadlessJsTaskSupport.notifyTaskFinished(taskId),
+        if (NativeHeadlessJsTaskSupport) {
-      )
+          NativeHeadlessJsTaskSupport.notifyTaskFinished(taskId);
+        }
+      })
       .catch(reason => {
         console.error(reason);
-        NativeModules.HeadlessJsTaskSupport.notifyTaskFinished(taskId);
+        if (NativeHeadlessJsTaskSupport) {
+          NativeHeadlessJsTaskSupport.notifyTaskFinished(taskId);
+        }
       });
   },
 

Libraries/ReactNative/NativeHeadlessJsTaskSupport.js

@@ -0,0 +1,20 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ * @format
+ */
+
+'use strict';
+
+import type {TurboModule} from 'RCTExport';
+import * as TurboModuleRegistry from 'TurboModuleRegistry';
+
+export interface Spec extends TurboModule {
+  +notifyTaskFinished: (taskId: number) => void;
+}
+
+export default TurboModuleRegistry.get<Spec>('HeadlessJsTaskSupport');