bug: default value of user-agent flagged as bot by is-bot

[manuel-rw]

Hello,
I am using Umami to send some data from a server side Node.js application.
This applications uses @umami/node to send track data to the Umami instance.
Some example code for this:

const umamiInstance = new Umami();

umamiInstance.init({
  hostURL: UMAMI_HOST_URL,
  websiteId: UMAMI_WEBSITE_ID
});

await umamiInstance.track('my-event', {
  "exampleKey": "exampleValue"
});

The track() function returns a Response from the fetch:

node/index.ts

Lines 41 to 48 in 9331047

	return fetch(`${hostUrl}/api/send`, {
	method: 'POST',
	headers: {
	'Content-Type': 'application/json',
	'User-Agent': `Mozilla/5.0 Node/${process.version}`,
	},
	body: JSON.stringify({ type, payload }),
	});

I noticed that no matter what I configured, my Umami track events were not showing up in Umami.
So I decided to dig a bit in the code and found a potentially unwanted behaviour / default value.

In the Umami server, there are multiple paths for the runtime to go:

https://github.com/umami-software/umami/blob/7a75639dd3d7aeff46104b71ebfb3853fc0eee09/src/pages/api/send.ts#L85-L100

One of them is the bot check that will fail silently if the request is being detected as a bot by the is-bot package.
The default value of your library here is Mozilla/5.0 Node/${process.version} -> the variable interpolation doesn't matter in this case:

node/index.ts

Line 45 in 9331047

'User-Agent': `Mozilla/5.0 Node/${process.version}`,

is-bot detects this as a bot and will therefore return true on the check:

Therefore, Umami will silently drop this track event without log message or any indications why it failed. Additionally, the 200 status code indicates that the request was successful (which it wasn't).

A possible workaround is to set the undocumented variable DISABLE_BOT_CHECK to true - but this disables the check entirely.
It would be favorable if this library has a different user agent as the default value or supports setting a custom agent.

If Umami thinks that this is intended behavior, please add a log warning to Umami server.

The commit 9331047 has not changed this problem, because the regex from is-bot will match either user agent.