Test isolation validation not working

[tsagadar]

Based on the test isolation validation documentation I adjusted the Super Rental example to contain a test that should trigger the validation - but it won't (code can be found here).

Turns out that test execution is done with waitForSettled = true. As a result, the isolation validation at the end of each test will never check for problems:

  test.finish = function () {
    let doFinish = () => finish.apply(this, arguments);

    if (isSettled()) {
      return doFinish(); // <--- always ends up here
    } else {
       ...               // <--- here the validation would happen
    }

Setting waitForSettled = false in setupTestIsolationValidation has no effect as it is done too late - start already initialised all the tests and set waitForSettled = true in the qunit context.