Now official google-closure-compiler has the CLI command. Just use it!
closure-compiler-cli
Thin CLI wrapper for google-closure-compiler

How to install
$ npm i -g closure-compiler-cli
and java
is required in your PATH
.
Usage
$ closure-compiler --some --options foo bar
equals to
$ java -jar path/to/compiler.jar --some --options foo bar
Why?
If closure-compiler-cli
is installed in your project local, you can use Closure Compiler in npm scripts
like
{
"scripts": {
"minify": "closure-compiler ./src/app.js > ./dist/bundle.js"
}
}
instead of
{
"scripts": {
"minify": "java -jar ./node_modules/google-closure-compiler/compiler.jar ./src/app.js > ./dist/bundle.js"
}
}
The path to the compiler jar is changable and provided with require('google-closure-compiler').compiler.COMPILER_PATH
officially, but it's API only for Node.js and not available for shell script.
License
MIT License: Teppei Sato <teppeis@gmail.com>