Cypress Testing - expect text to be one of

I want to test against the values of an array of elements & the text content of each element should be one of 'a' or 'b'.

it("should display for adventure & cabin charter when both are the only ones selected", () => {
    cy.get("button.expCategoryBtn")
      .contains("a")
      .click();
    cy.get("button.expCategoryBtn")
      .contains("b")
      .click();
    // the following line doesnt work
    cy.get("div.tag").each(x => {
    // the problem line:
    // I want to get the text value of each el & expect
    // it to be one of a or b
      expect(cy.wrap(x).invoke("text")).to.be.oneOf([
        "a",
        "b"
      ]);
    });
  });