I read the following documentation where it clearly says that under Production mode,
Optimization and minification are performed on framework code only. Custom component code is not minified or obfuscated. Untouched custom component code includes both components you create yourself, and components installed as part of a managed package.
so custom component code is not minified or obfuscated in production mode. Is there any other way to make it possible? The issue is that when I use Developer tools of Chrome and navigate to Source tab, JS code of individual Lightning component is properly formatted and readable.
https://developer.salesforce.com/docs/atlas.en-us.lightning.meta/lightning/aura_debug_mode.htm