Emulate offline

(taken from https://github.com/gr2m/headless-chrome-test/issues/1)

Puppeteer should have an offline mode to test PWA’s. For example:

page.setOfflineMode(true);

Emulation of other network conditions might be useful as well, but we can wait with them until there are good scenarios.

[aslushnikov]

wait, we still want to have page.setOfflineMode implemented 😃

[Garbee]

If you don’t want to run as root but still want to have some level of automated traffic shaping (even if low fidelity). Then what you’d want to do is setup a proxy for those tests. Do it where any tests that need throttling use an instance that is talking to your proxy that will handle the network manipulation. You’d pass the proxy in when launching an instance just like you would from the command line as an arg option.

let instance = puppeteer.launch({
  args: [
   '--proxy-server=127.0.0.1:9876', // Or whatever the address is 
  ]
});

This allows you to use other external tools to manage the network shaping. Such as Charles Proxy on Mac OS. Finding a good cross-platform solution for testing is difficult though, as Windows in particular is dramatically different to talk to.