Usage
  uglifyjs-folder path [options]

options:
  -c --comments      Add a comment with the file name.
  -o --output        Specify a file/folder to write the minified code
  -e --each          Minify each file independently
  -x --extension     Minified file extension (default: .min.js)
  -p --pattern       Specifies a comma separated glob patterns for the file selections. Default: **/*.js
     --pseparator    Specifies the separator for the pattern input. Default: ,
     --version       Prints the current version from package.json
     --config-file   Specifies a json configuration file for the terser module
     --log-level     Specifies the log level used when processing the files. Default: info
  -h --help          Print this list and exit.

$ uglifyjs-folder test-folder
$ uglifyjs-folder test-folder --comments
$ uglifyjs-folder test-folder -o all.min.js
$ uglifyjs-folder test-folder --output all.min.js --pattern "**/*.js,!**/*min.js" # ignore minified files 
$ uglifyjs-folder test-folder -eo newFolder
$ uglifyjs-folder test-folder -eo newFolder --log-level error
$ uglifyjs-folder test-folder-es6 -o newFolder
$ uglifyjs-folder test-folder -e -x .js -o test-folder # careful: overwrite all files in test-folder
$ uglifyjs-folder test-folder --config-file "./uglify.json"
where uglify.json contains
{
  "keep_fnames": true
}

{
  "sourceMap": {
    "root": "../src",
    "url": "{file}.map"
  }
}