One line to safely minimize js files using sed(there will be single spaces left to not break variable assignment)

minimizeJs.sh

# Requires appropriate semi-colons
FILE_PATH=$(pwd); for i in $(ls $FILE_PATH/*.js); do sed -i 's|//.*||g; /\/\*/,/*\//d; /^\s*$/d;' $i && sed -i ':a;N;$!ba;s/\n/ /g; s/  //g' $i; done

# Before
# const os = require('os');

# function num(num){
#     return 5 + num
# }
# // Sample Comment

# /* More
#    Comments
# */

# module.exports = {
#     "randNum": num(5),
#     "host": {
#         "name": os.hostname(),
#         "homeDir": os.homedir()
#     }
# };

# After
# const os = require('os'); function num(num){ return 5 + num } module.exports = { "randNum": num(5), "host": { "name": os.hostname(), "homeDir": os.homedir() } }