Test with timeout and missing assert.async() call never times out

[patricklx]

related issue: emberjs/ember-qunit#476

Tell us about your runtime:

• QUnit version: 2.19.1
• Which environment are you using? (e.g., browser, Node): browser
• How are you running QUnit? (e.g., QUnit CLI, Grunt, Karma, manually in browser): browser, jsfiddle

Code that reproduces the problem:

QUnit.test( "demo", async assert => {
	assert.timeout( 10 );
	const done = assert.async();
	assert.true( true );
} );

https://jsfiddle.net/fasjpd49/

[Krinkle]

Thanks for reporting. I've confirmed the issue, and it appears to be a regression from an earlier version. https://codepen.io/Krinkle/pen/ExLzzVv

Times out as expected	QUnit 2.14, 2.15, 2.16
Never-ending	QUnit 2.17, 2.18, 2.19