Add new tracker for React Native

[matus-tomlein]

Adds the @snowplow/react-native-tracker package to the monorepo.

This aims to move the React Native tracker to instead of using the iOS and Android trackers as the base for the React Native tracker, to use the JavaScript tracker. The motivation for this is to:

1. support Expo Go (managed workflow) and React Native for Web
2. better support React Native new architecture without the interoperability layer
3. make the tracker easier to maintain going forward (simplifies the project)
4. be able to use JS tracker plugins (or some of them) in the RN tracker and vice versa

The package will continue with the @snowplow/react-native-tracker starting from version 4.1 (or later). We decided for this as opposed to introducing a new package to make it more clear long term that this package replaces the old RN tracker and avoid having two RN packages. We will need to skip v3 (RN tracker is now on v2) in order to sync with the JS tracker versions.

This PR implements the core of the tracker without additional features (such as session, lifecycle tracking) which will be introduced in follow up PRs. It tries to maintain the API from the RN tracker but for the createTracker method, this was not possible and I think it's better to follow the newTracker convention in the JS tracker. So the newTracker method signature is a breaking change.

I have deployed the package under the version 4.0.1-dev.1 and added a very simple example app in the examples repo using it: snowplow-incubator/snowplow-javascript-tracker-examples#60 (we'll improve it over time)

[bundlemon]

BundleMon

Files added (6)

Status	Path	Size	Limits
✅	trackers/javascript-tracker/dist/sp.js	+24.49KB	30KB / +10%
✅	libraries/browser-tracker-core/dist/index.mod ule.js	+23.44KB	25KB / +10%
✅	libraries/tracker-core/dist/index.module.js	+19.48KB	20KB / +10%
✅	trackers/browser-tracker/dist/index.umd.min.j s	+17.4KB	20KB / +10%
✅	trackers/javascript-tracker/dist/sp.lite.js	+17.33KB	20KB / +10%
✅	trackers/browser-tracker/dist/index.module.js	+3.49KB	5KB / +10%

Total files change +105.62KB 0%

Final result: ✅

View report in BundleMon website ➡️

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Current branch size history

[Mookiies]

Am I correct that this gets rid of the removeTracker method?

I know this doesn't have the native tie-in plugins yet, but will that be something that's safe to get rid of? Thinking of the things like application_foreground that might get duplicated if you can't remove a tracker.

[matus-tomlein]

Thanks for looking into this and the feedback!

That's correct, we don't have the removeTracker function here. We can look into it adding it though, it's a good feedback.

But I'm not sure I understand the relation to the application_foreground event. The tracker shouldn't be removed when the app goes to background/foreground. In order to calculate session metrics correctly, the same tracker instance should be maintained. So normally you would only create a new tracker on app start and then keep the tracker instance for the duration of the app lifetime.

[Mookiies]

As an example we have a legacy version of the app and a new part, each with their respective trackers both track the application lifecycle. When we swap between the two we removeTracker. If we didn't I think we'd get duplicate events sent, which is why I mention application_foreground.

So the case I'm thinking about is: if you setup a plugin to automatically send events for you, how to you get it to stop?

[matus-tomlein]

Ah, I see, that makes sense! Will think about how we can introduce the removeTracker option here or at least have a way to pause the tracker.