Set __DEV__ of RN packager output to false

boot-react-native-no-dev.py

#!/usr/bin/env python
#
# boot-react-native-no-dev.py
#
# Patch jsbundle to set __DEV__ to false
#
# The React Native packager often cannot handle Google Closure-generated JS files
# if `--dev false` is set, eventually running out of memory. As a workaround,
# use `--dev true` and patch the __DEV__ setting in the output bundle to
# false.
#
# Usage:
#
#   python boot-react-native-no-dev.py < bundle.js > output.js

import sys, re

print(re.sub(r'__DEV__\s*=\s*true;', "__DEV__=false;",
        sys.stdin.read()))