Change default tracker initialization parameters for JS/Browser v4

[Peter Perlepes (igneel64)]

This PR includes the proposed changes for the JS/Browser tracker initialization parameters:

Currently it includes:

• discoverRootDomain: The default becomes true
• configCookieSameSite: The default becomes Lax

A bit more info:

discoverRootDomain

On the previous version this value defaulted to false.

This had an important effect when used as a default. If the tracker was installed in a subdomain (foo.example.com), or any number of subdomains (bar.example.com etc), and a TLD (example.com), then all instances had different domain userIds.

That would make the analysis a bit more challenging when trying to count unique users, without the existance of user ID (uid), and cross TLD-subdomain behaviours/attribution.

The behaviour now mimics what other tools like Google Analytics have as a default.

configCookieSameSite

This was set as the recommended value of Lax but defaults to None which seems to have caused some issues for unsupported browsers and tracking use cases.
Since our v4 compatibility does not allow us to follow the changes made in latest browser versions, this would be a good default to follow for this version:
More info:

• https://snowplow.io/blog/understanding-the-samesite-cookie-update/
• https://www.chromium.org/updates/same-site/incompatible-clients/

[bundlemon]

BundleMon

Files added (6)

Status	Path	Size	Limits
✅	libraries/browser-tracker-core/dist/index.mod ule.js	+23.87KB	25KB / +10%
✅	trackers/javascript-tracker/dist/sp.js	+22.49KB	25KB / +10%
✅	trackers/javascript-tracker/dist/sp.lite.js	+13.93KB	15KB / +10%
✅	trackers/browser-tracker/dist/index.umd.min.j s	+13.78KB	15KB / +10%
✅	libraries/tracker-core/dist/index.module.js	+13.36KB	15KB / +10%
✅	trackers/browser-tracker/dist/index.module.js	+3.46KB	5KB / +10%

Total files change +90.88KB 0%

Final result: ✅

View report in BundleMon website ➡️

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Current branch size history

[Matus Tomlein (matus-tomlein)]

LGTM, nice change! 👍

I can't comment in the file directly, but can you fix the API comments in the types.ts file? It still says that the default for discoverRootDomain is false and for cookieSameSite is None.

[Peter Perlepes (igneel64)]

Sure thanks!

[Paul Boocock (paulboocock)]

On discoverRootDomain, I've never been a big fan of how it tries to keep setting cookies. This usually leads of console warnings, which is always unfortunate. I'd prefer to not have a default value which commonly produces warnings.

However, I do see the benefit in making the default cookie domain the root... maybe we can try and find it another way - trim window.location to the typical value and try to set the cookie? Maybe a little regex solves this. Worst case, we fallback to cycle through the other options if we don't find the root straight away?

[Peter Perlepes (igneel64)]

Paul Boocock (@paulboocock)
Summing up, together with this change we can refine a bit the way we try to find the root right ? (I think it can fit this PR and can be quite straightforward)

[Peter Perlepes (igneel64)]

On discoverRootDomain, I've never been a big fan of how it tries to keep setting cookies. This usually leads of console warnings, which is always unfortunate. I'd prefer to not have a default value which commonly produces warnings.

However, I do see the benefit in making the default cookie domain the root... maybe we can try and find it another way - trim window.location to the typical value and try to set the cookie? Maybe a little regex solves this. Worst case, we fallback to cycle through the other options if we don't find the root straight away?

Addressed at #1163