Modify based on review

- Update licenses date to 2020 (from 2017, 2018)
- Declare Module in `registerMessagingCompat.ts`
- Update build rule (package.json):
   -- add `app-comapt` as a dev dependency

Author: zwu52

packages-exp/messaging-compat/README.md

@@ -1,5 +1,5 @@
 # @firebase/messaging-compat
 
-This is the compat package that recreates the v7 APIs.
+This is the compat package that recreates the v8 APIs.
 
 **This package is not intended for direct usage, and should only be used via the officially supported [firebase](https://www.npmjs.com/package/firebase) package.**

packages-exp/messaging-compat/karma.conf.js

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2017 Google LLC
+ * Copyright 2020 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

packages-exp/messaging-compat/package.json

@@ -38,6 +38,7 @@
     "tslib": "^1.11.1"
   },
   "devDependencies": {
+    "@firebase/app-compat": "0.0.900",
     "@rollup/plugin-json": "4.1.0",
     "rollup-plugin-typescript2": "0.29.0",
     "ts-essentials": "7.0.1",

packages-exp/messaging-compat/rollup.config.js

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2018 Google LLC
+ * Copyright 2020 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

packages-exp/messaging-compat/rollup.config.release.js

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2018 Google LLC
+ * Copyright 2020 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

packages-exp/messaging-compat/src/registerMessagingCompat.ts

@@ -22,9 +22,19 @@ import {
   InstanceFactory
 } from '@firebase/component';
 
+import { FirebaseApp } from '@firebase/app-compat';
+import { FirebaseMessaging } from '@firebase/messaging-exp';
 import { MessagingCompat } from './messaging-compat';
 import { _registerComponent } from '@firebase/app-exp';
 
+declare module '@firebase/component' {
+  interface NameServiceMapping {
+    'app-compat': FirebaseApp;
+    'messaging-compat': MessagingCompat;
+    'messaging-exp': FirebaseMessaging;
+  }
+}
+
 const messagingCompatFactory: InstanceFactory<'messaging-compat'> = (
   container: ComponentContainer
 ) => {
@@ -36,6 +46,10 @@ const messagingCompatFactory: InstanceFactory<'messaging-compat'> = (
 
 export function registerMessagingCompat(): void {
   _registerComponent(
-    new Component('messaging-exp', messagingCompatFactory, ComponentType.PUBLIC)
+    new Component(
+      'messaging-compat',
+      messagingCompatFactory,
+      ComponentType.PUBLIC
+    )
   );
 }