From c5a6ed0839c3a78d15cdc48e9c2a0110e86c241a Mon Sep 17 00:00:00 2001
From: Pascal Hartig <realpassy@fb.com>
Date: Mon, 3 Jun 2019 07:04:17 -0700
Subject: [PATCH] Explicitly type service worker registration

Summary: Per title.

Reviewed By: danielbuechele

Differential Revision: D15601531

fbshipit-source-id: 251949faffd75cf8b59a71c3963230113b0ebb0c
---
 src/init.js | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/init.js b/src/init.js
index 055727877..6dd0c3c8b 100644
--- a/src/init.js
+++ b/src/init.js
@@ -54,8 +54,13 @@ function init() {
         ? path.join(__dirname, 'serviceWorker.js')
         : './serviceWorker.js',
     )
-    .then(r => {
-      (r.installing || r.active).postMessage({precachedIcons});
+    .then((r: ServiceWorkerRegistration) => {
+      const client = r.installing || r.active;
+      if (client != null) {
+        client.postMessage({precachedIcons});
+      } else {
+        console.error('Service worker registration failed: ', r);
+      }
     })
     .catch(console.error);