const calls = [];

`
  ${
    (calls.push(1), {
      [Symbol.toPrimitive](){
        calls.push(2);
        return 'foo';
      }
    })
  }
  ${
    (calls.push(3), {
      [Symbol.toPrimitive](){
        calls.push(4);
        return 'bar';
      }
    })
  }
`;

expect(calls).toEqual([1, 2, 3, 4]);