Open a tab, Switch between tabs, close tab on browser not working on Playwright Typescript

I'm opening a tab (t1) using beforeEach, from that I'm opening another tab (t2). Now, I want to perform some actions on (t2) and switch to (t1). And then, close a (t2) tab.

  test.beforeEach(async ({ page }) => {
   await page.goto(BASE_URL + "/t1");
  });


test("switch between tabs", async ({ context }) => {

  const page = await context.newPage();

  const [newtab] = await Promise.all([
    context.waitForEvent('page'),    
    await page.goto(BASE_URL + "/t2"),
    await page.getByTestId('id_here').click(),
    await page.getByTestId('id1_here').fill('test')
 ])
 //come back to tab (t1)
 //perform actions on tab (t1)
 //close tab (t2)

});

You can use context.pages() to keep track of the open windows within the test context. This will follow even the window opened during your beforeEach.

test.beforeEach(async ({ page }) => {
   await page.goto(BASE_URL + "/w1");
});

test('Foo', async ({ context }) => {
  const w2 = await context.newPage();
  const w1 = context.pages()[0]; // assumes that the first page opened always occupies the first position in the array
  // alternatively...
  const w1Alt = context.pages().find(x => x.url() === BASE_URL + "/w1")
});

Alternatively, you could keep track of the w1 window by assigning the page from your beforeEach to a variable.

let w1: Page;

test.beforeEach(async ({ page }) => {
  w1 = page;
  await w1.goto(BASE_URL + "/w1");
});

test('Foo', async ({ context }) => {
  const w2 = await context.newPage();
  await w2.goto(BASE_URL + "/w2");
  // use w1 and w2 to reference each page
  await expect(w1).toHaveURL(BASE_URL + "/w1");
  await expect(w2).toHaveURL(BASE_URL + "/w2");
});