The `TEST-UNEXPECTED-FAIL | checks that docIds are unique and increasing | in chrome | Expected 9 to be less than 0` unit test failed in a recent test run in https://github.com/mozilla/pdf.js/pull/13837#issuecomment-890511627, but also locally once for me. Perhaps this goes wrong because the test depends on state that might be mutated if the tests are shuffled?

/cc @Snuffleupagus since this unit test was added in https://github.com/mozilla/pdf.js/pull/13813/commits/b18620ac0f196c6fa5a9e54a53fa6b915e19e843
const pdfPage = await pdfDoc.getPage(1);
      const { items, styles } = await pdfPage.getTextContent();
      expect(items.length).toEqual(1);
      
      const fontName = items[0].fontName;
      expect(Object.keys(styles)).toEqual([fontName]);
      expect(items[0]).toEqual({
        dir: "ltr",
        fontName,
        height: 18,
        str: "Issue 8276",
        transform: [18, 0, 0, 18, 441.81, 708.4499999999999],
        width: 77.49,
        hasEOL: false,
      });
      expect(styles[fontName]).toEqual({
        fontFamily: "serif",
        ascent: NaN,
        descent: NaN,
        vertical: false,
      });
      await loadingTask.destroy();
    });
    it("gets empty structure tree", async function () {
      const tree = await page.getStructTree();
      expect(tree).toEqual(null);
    });
    it("gets simple structure tree", async function () {
      const loadingTask = getDocument(
        buildGetDocumentParams("structure_simple.pdf")