Add an emitter and event store interface in the tracker core to be used both by the browser and node trackers and use fetch API for making requests (close #1076)

[Matus Tomlein (matus-tomlein)]

This PR replaces the XMLHttpRequest API in the browser tracker and the got library in the Node tracker with the fetch API in order to make requests to the collector using a common code base.

The changes are:

1. Add an Emitter in the tracker-core for making requests to the collector. This is used both by the Web and Node trackers.
2. Add an EventStore interface including an in-memory implementation in the tracker-core. On top of this, the Web trackers implement a local storage based event store. The Node tracker uses the tracker-core implementation.

The new Emitter and EventStore interfaces are Promise-based so can be used to await when the events are stored or sent to the collector. I didn't change any outward facing Web tracker APIs to expose the promises, we can consider that though.

There are various breaking changes, I'll need to make a full list and publish in docs.

As part of the work, I also had to update the Node.JS version used for the build – I set the supported versions to >=18.0.0 <25.0.0.

[bundlemon]

BundleMon

Files added (6)

Status	Path	Size	Limits
✅	trackers/javascript-tracker/dist/sp.js	+27.69KB	30KB / +10%
✅	libraries/browser-tracker-core/dist/index.mod ule.js	+22.25KB	25KB / +10%
✅	libraries/tracker-core/dist/index.module.js	+19.12KB	20KB / +10%
✅	trackers/browser-tracker/dist/index.umd.min.j s	+16.83KB	20KB / +10%
✅	trackers/javascript-tracker/dist/sp.lite.js	+16.81KB	20KB / +10%
✅	trackers/browser-tracker/dist/index.module.js	+3.49KB	5KB / +10%

Total files change +106.18KB 0%

Final result: ✅

View report in BundleMon website ➡️

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Current branch size history

[Jethro Nederhof (jethron)]

Awesome changes! Mostly LGTM, just a few things.

[Jethro Nederhof (jethron)]

LGTM. Appropriately epic PR for 1337, great work!

(Pretty sure tests just need to be more async friendly because it's a whole new task rather than microtask:)

       it('should fire on a successful request', async () => {
         const callbacks: EventBatch[] = [];
-        const onSuccess = (e: EventBatch) => {
-          callbacks.push(e);
-        };
 
-        const postQueue = createQueue({ method, onSuccess });
-        await postQueue.enqueueRequest(request);
+        await new Promise<void>(async (resolve) => {
+          const onSuccess = (e: EventBatch) => {
+            callbacks.push(e);
+            resolve();
+          };
+
+          const postQueue = createQueue({ method, onSuccess });
+          await postQueue.enqueueRequest(request);
+        });
 
         expect(requests).toHaveLength(1);
         expect(eventStore.addCount()).toEqual(1);

[Matus Tomlein (matus-tomlein)]

Thanks a lot for the in depth review Jethro Nederhof (@jethron), that was super helpful!