Prevent infinite loop when title attribute is changed

[dmarcey]

Fixes #130

I tried adding a test case here to use a MutationObserver to ensure that we weren't continuously calling the callback, but I couldn't get it to work.

If anyone has any suggestions on a good way to write a test, let me know!

[keithamus]

Thanks for catching this and providing a fix @dmarcey!

Are we able to write a test that changes the attribute title and ensures that there's no stack overflow? Perhaps try/catching a setAttribute call?

@muan thoughts?

[dmarcey]

I tried a test like this:

test('title change does not throw RangeError', function() {
  const time = document.createElement('local-time')

  try {
    time.setAttribute('title', 'custom title')
  } catch (e) {
    assert.fail(`Error thrown: ${e.message}`)
  }
})

and it didn't fail without my change, unfortunately

[muan]

Thanks for catching and fixing this.

@keithamus Looks like the error is just not reported? The error shows up when I run the test in browser mode, but the tests pass regardless.

[dmarcey]

@muan should I bump the package version to 3.0.10?

[muan]

We can do that after this is merged.