Split bundle compatibility for runtime vars (#14)

.profile.d/inject_react_app_env.sh

@@ -1,26 +1,28 @@
 #!/bin/bash
-
-# Fail immediately on non-zero exit code.
-set -e
 # Debug, echo every command
 #set -x
 
 # Each bundle is generated with a unique hash name to bust browser cache.
 # Use shell `*` globbing to fuzzy match.
-js_bundle="${JS_RUNTIME_TARGET_BUNDLE:-/app/build/static/js/main.*.js}"
+# create-react-app v2 with Webpack v4 splits the bundle, so process all *.js files.
+js_bundles="${JS_RUNTIME_TARGET_BUNDLE:-/app/build/static/js/*.js}"
+# Get exact filenames.
+js_bundle_filenames=`ls $js_bundles`
 
-if [ -f $js_bundle ]
+if [ ! "$?" = 0 ]
 then
+  echo "Error injecting runtime env: bundle not found '$js_bundles'. See: https://github.com/mars/create-react-app-buildpack/blob/master/README.md#user-content-custom-bundle-location"
+fi
 
-  # Get exact filename.
-  js_bundle_filename=`ls $js_bundle`
-
+# Fail immediately on non-zero exit code.
+set -e
+
+for js_bundle_filename in $js_bundle_filenames
+do
   echo "Injecting runtime env into $js_bundle_filename (from .profile.d/inject_react_app_env.sh)"
 
   # Render runtime env vars into bundle.
   ruby -E utf-8:utf-8 \
-    -r /app/.heroku/create-react-app/injectable_env.rb \
-    -e "InjectableEnv.replace('$js_bundle_filename')"
-else
-  echo "Error injecting runtime env: bundle not found '$js_bundle'. See: https://github.com/mars/create-react-app-buildpack/blob/master/README.md#user-content-custom-bundle-location"
-fi
+   -r /app/.heroku/create-react-app/injectable_env.rb \
+   -e "InjectableEnv.replace('$js_bundle_filename')"
+done