I have a file hello-world.iife.js, which is a bundled Preact widget.

When I compile hello-world.iife.js with https://closure-compiler.appspot.com/home, I can use it in Firefox 5.

When I compile hello-world.iife.js through either google-closure-compiler npm package, the .jar application provided by Google, or even a community maintained Rollup plugin (based on google-closure-compiler), the code does not work in Firefox 5 (although the code is compiled successfully).

The code I get from the two different methods of compilation is different (which shouldn't be if I'm using the same settings, right?). What am I missing?

The script that I'm using to compile the JavaScript using the .jar is java -jar compiler.jar --js dist/preact-hello.iife.js --js_output_file hello-compiled.js --compilation_level SIMPLE