Cannot see any JavaScript files in a Chrome extension

Question

As I concern security and privacy, also actually I'm facing Chrome(actually chromium Brave)'s high CPU problem, I needed to check source code of suspicious extensions I have.

So first I tried to inspect an extension called Visited (bfcodeehkjogenemacopdbhabjebnbah), it's very simple extension so I thought it shouldn't be hard to inspect. (but of course it should contains at least some JS files, background.js)

But when I opened Default\Extensions\bfcodeehkjogenemacopdbhabjebnbah on my editor, there is no JS files, but only five files:

• _metadata\verified_contents.json
• _metadata\computed_hashes.json
• custom.css
• icon128.png
• manifest.json

It's so strange.

I also read gist to inspect Chrome extension source code, I tried all the curl clients2.google.com/service/update2/crx way, robwu.nl/crxviewer way, Chrome extension source viewer way. But none of them worked or showed me the with-no-JS-files source tree.

Where the hell is background.js and JS files? How can I see these files??

Answer 1

It was because that the extension is implemented only with the one CSS file, and without having power of any JavaScript.

Also I tried debugging the source code with editor and confirmed it works as expected.