From 658c09479aa95b44d65a0ebd198eae387b72e0fd Mon Sep 17 00:00:00 2001
From: Rory Abraham <rory@expensify.com>
Date: Sat, 19 Jun 2021 19:56:31 -0700
Subject: [PATCH] Make GitHub Actions build asynchronously

---
 .github/scripts/buildActions.sh | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/.github/scripts/buildActions.sh b/.github/scripts/buildActions.sh
index 8b95647248b7..5b417b094f99 100755
--- a/.github/scripts/buildActions.sh
+++ b/.github/scripts/buildActions.sh
@@ -28,12 +28,26 @@ declare -r NOTE_DONT_EDIT='/**
  */
 '
 
-for ACTION in "${GITHUB_ACTIONS[@]}"; do
-    # Build the action
-    ACTION_DIR=$(dirname "$ACTION")
-    ncc build "$ACTION" -o "$ACTION_DIR"
-
-    # Prepend the warning note to the top of the compiled file
-    OUTPUT_FILE="$ACTION_DIR/index.js"
-    echo "$NOTE_DONT_EDIT$(cat "$OUTPUT_FILE")" > "$OUTPUT_FILE"
+# This stores all the process IDs of the ncc commands so they can run in parallel
+declare ASYNC_BUILDS
+
+for ((i=0; i < ${#GITHUB_ACTIONS[@]}; i++)); do
+  ACTION=${GITHUB_ACTIONS[$i]}
+  ACTION_DIR=$(dirname "$ACTION")
+
+  # Build the action in the background
+  ncc build "$ACTION" -o "$ACTION_DIR" &
+  ASYNC_BUILDS[$i]=$!
+done
+
+for ((i=0; i < ${#GITHUB_ACTIONS[@]}; i++)); do
+  ACTION=${GITHUB_ACTIONS[$i]}
+  ACTION_DIR=$(dirname "$ACTION")
+
+  # Wait for the background build to finish
+  wait ${ASYNC_BUILDS[$i]}
+
+  # Prepend the warning note to the top of the compiled file
+  OUTPUT_FILE="$ACTION_DIR/index.js"
+  echo "$NOTE_DONT_EDIT$(cat "$OUTPUT_FILE")" > "$OUTPUT_FILE"
 done