Compression not working in Heroku

[cythilya]

I have gzip when I run "yarn run dev" in local, but after I run "heroku local" or deploy my app to Heroku, gzip is gone. Below are my code snippet.

package.json

"compression": "^1.7.3",
"express": "4.16.2",

server.js

const server = express();
server.use(compression());

or view my repo and demo.

[dougwilson]

Can you provide a specific example URL to call so I can test the same one (since there are lots of URLs in that app)?

[cythilya]

Please view this url.

When I run in local "yarn run dev"

After I deploy my app to Heroku

[dougwilson]

Yea, I'm also not seeing it as compressed. Is there a way to attach a debugger into the running code on Heroku to see what is happening?

[Avcajaraville]

Same here, my assets are not being compressed and they are reported by google page speed as not compressed :)

CSS and JS files are being compress, everything else, is not. Weird.

Using:

"compression": "^1.7.3",
"express": "^4.16.3",
"node": "8.10.0"

Here is my site.

If you check the network panel, you'll see how the only assets being compressed are CSS & JS file. Fonts, svgs, etc are not.

This is how I use the module:

Thanks

[Avcajaraville]

Actually, this problem is not related to Heroku, as in local the same results are outputted on the network tab.

So, its reproducible also in local environments.

[dougwilson]

Hi @Avcajaraville sorry to hear you're having the same issue. I would live to debug through the issue to get to a resolution. Can you provide code and steps to reproduce so I can examine?

[Avcajaraville]

@dougwilson I just set a minimum gist that reproduces the issue here

As you can see, the css file is being gzip, while the svg is not:

[dougwilson]

Ah, thanks @Avcajaraville ! This is because the SVG file in your example does not exceed the default value for the threshold option (https://github.com/expressjs/compression#threshold) which is 1kb. Responses below that threshold size are not compressed. You can lower the threadshold if you need it compressed 👍

[Avcajaraville]

Thanks a lot @dougwilson that was a super useful and quick answer :)

This is also the reason why this is not working for @cythilya.

We should read the docs more carefully :)

Really nice response time and great job with this module !!

[dougwilson]

It's no problem! Happy to help.