How to properly use Form Context?

We are using Event and Form Context in our forms, and when writing tests with xrm-mock, the changes that are done in the code are then not reflected in the test.

Here is the test result: Expected: "Notes (2)" Received: "Notes"

This is how my test looks like:

import { XrmMockGenerator }  from "xrm-mock"
import account from "../account_main"
import * as sinon from "sinon"

describe("account", () => {
    beforeEach(() => {
      XrmMockGenerator.initialise();
    });

    it("count notes and update the label", () => {
      XrmMockGenerator.Tab.createTab("notes", "Notes", true);
      var context = XrmMockGenerator.getEventContext();

      const stub = sinon.stub(Xrm.WebApi, "retrieveMultipleRecords").resolves({
        entities: ["1", "2"],
        nextLink: null
      });

      account.showAttachmentCount(context);

      let tab = context.formContext.ui.tabs.get('notes');

      expect(tab.getLabel()).toBe("Notes (2)"); // Pass
    });

});

This is the function that is being tested:

static showAttachmentCount(context: Xrm.Events.EventContext) {
        const formContext = context.getFormContext();

        var filter = "?$select=subject&$filter=_objectid_value eq (" + formContext.data.entity.getId() + ")";

        Xrm.WebApi.retrieveMultipleRecords("annotation", filter).then(notes => {
            if (notes.entities.length > 0) {
                var tab = formContext.ui.tabs.get('notes');

                if (tab !== null) {
                    console.log(tab.getLabel());
                    tab.setLabel(tab.getLabel() + ' (' + notes.entities.length.toString() + ')');
                }
            }
        }).catch();
    }

What am I doing wrong here? Do I need to apply the changes to the context somehow?

camelCaseDave / xrm-mock

How to properly use Form Context? #58