From 9dd550fa1e1ba710055b683d1c6cb87bd499fd3d Mon Sep 17 00:00:00 2001
From: George Kalpakas <kalpakas.g@gmail.com>
Date: Sat, 8 Jul 2017 02:35:07 +0300
Subject: [PATCH] ci(aio): only deploy latest commits to staging/production
 (#17988)

Fixes #17941
---
 aio/scripts/deploy-to-firebase.sh | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/aio/scripts/deploy-to-firebase.sh b/aio/scripts/deploy-to-firebase.sh
index 24279d6648..a14ba8965b 100755
--- a/aio/scripts/deploy-to-firebase.sh
+++ b/aio/scripts/deploy-to-firebase.sh
@@ -25,6 +25,14 @@ case $deployEnv in
     ;;
 esac
 
+# Do not deploy if the current commit is not the latest on its branch.
+readonly LATEST_COMMIT=$(git ls-remote origin $TRAVIS_BRANCH | cut -c1-40)
+if [ $TRAVIS_COMMIT != $LATEST_COMMIT ]; then
+  echo "Skipping deploy because $TRAVIS_COMMIT is not the latest commit ($LATEST_COMMIT)."
+  exit 0
+fi
+
+# Deploy
 (
   cd "`dirname $0`/.."