diff --git a/test/custom-elements/samples/nested/test.js b/test/custom-elements/samples/nested/test.js
index b9303f1e26..d6d52426af 100644
--- a/test/custom-elements/samples/nested/test.js
+++ b/test/custom-elements/samples/nested/test.js
@@ -1,7 +1,7 @@
 import * as assert from 'assert';
 import './main.html';
 
-export default function (target) {
+export default async function (target) {
 	target.innerHTML = '<my-app/>';
 	const el = target.querySelector('my-app');
 	const counter = el.shadowRoot.querySelector('my-counter');
@@ -10,7 +10,7 @@ export default function (target) {
 	assert.equal(counter.count, 0);
 	assert.equal(counter.shadowRoot.innerHTML, `<button>count: 0</button>`);
 
-	button.dispatchEvent(new MouseEvent('click'));
+	await button.dispatchEvent(new MouseEvent('click'));
 
 	assert.equal(counter.count, 1);
 	assert.equal(counter.shadowRoot.innerHTML, `<button>count: 1</button>`);
diff --git a/test/hydration/samples/binding-input/_config.js b/test/hydration/samples/binding-input/_config.js
index 62a4721850..422e2a496c 100644
--- a/test/hydration/samples/binding-input/_config.js
+++ b/test/hydration/samples/binding-input/_config.js
@@ -10,7 +10,7 @@ export default {
 		};
 	},
 
-	test(assert, target, snapshot, component, window) {
+	async test(assert, target, snapshot, component, window) {
 		const input = target.querySelector('input');
 		const p = target.querySelector('p');
 
@@ -18,7 +18,7 @@ export default {
 		assert.equal(p, snapshot.p);
 
 		input.value = 'everybody';
-		input.dispatchEvent(new window.Event('input'));
+		await input.dispatchEvent(new window.Event('input'));
 
 		assert.equal(component.name, 'everybody');
 		assert.htmlEqual(target.innerHTML, `
diff --git a/test/hydration/samples/event-handler/_config.js b/test/hydration/samples/event-handler/_config.js
index f5676ac8e2..d231e1fd0d 100644
--- a/test/hydration/samples/event-handler/_config.js
+++ b/test/hydration/samples/event-handler/_config.js
@@ -11,11 +11,11 @@ export default {
 		};
 	},
 
-	test(assert, target, snapshot, component, window) {
+	async test(assert, target, snapshot, component, window) {
 		const button = target.querySelector('button');
 		assert.equal(button, snapshot.button);
 
-		button.dispatchEvent(new window.MouseEvent('click'));
+		await button.dispatchEvent(new window.MouseEvent('click'));
 
 		assert.ok(component.clicked);
 		assert.htmlEqual(target.innerHTML, `
diff --git a/test/runtime/samples/action-function/_config.js b/test/runtime/samples/action-function/_config.js
index fcbfd2ac82..b6bd59595f 100644
--- a/test/runtime/samples/action-function/_config.js
+++ b/test/runtime/samples/action-function/_config.js
@@ -3,20 +3,20 @@ export default {
 		<button>action</button>
 	`,
 
-	test ( assert, component, target, window ) {
-		const button = target.querySelector( 'button' );
-		const eventEnter = new window.MouseEvent( 'mouseenter' );
-		const eventLeave = new window.MouseEvent( 'mouseleave' );
+	async test(assert, component, target, window) {
+		const button = target.querySelector('button');
+		const eventEnter = new window.MouseEvent('mouseenter');
+		const eventLeave = new window.MouseEvent('mouseleave');
 
-		button.dispatchEvent( eventEnter );
-		assert.htmlEqual( target.innerHTML, `
+		await button.dispatchEvent(eventEnter);
+		assert.htmlEqual(target.innerHTML, `
 			<button>action</button>
 			<div class="tooltip">Perform an Action</div>
-		` );
+		`);
 
-		button.dispatchEvent( eventLeave );
-		assert.htmlEqual( target.innerHTML, `
+		await button.dispatchEvent(eventLeave);
+		assert.htmlEqual(target.innerHTML, `
 			<button>action</button>
-		` );
+		`);
 	}
 };
diff --git a/test/runtime/samples/action-ternary-template/_config.js b/test/runtime/samples/action-ternary-template/_config.js
index 53d83b5958..9666853b1e 100644
--- a/test/runtime/samples/action-ternary-template/_config.js
+++ b/test/runtime/samples/action-ternary-template/_config.js
@@ -8,11 +8,11 @@ export default {
 		<h1></h1>
 	`,
 
-	test(assert, component, target, window) {
+	async test(assert, component, target, window) {
 		const header = target.querySelector('h1');
 		const click = new window.MouseEvent('click');
 
-		header.dispatchEvent(click);
+		await header.dispatchEvent(click);
 		assert.htmlEqual(target.innerHTML, `
 			<h1>Hello World!</h1>
 		`);
diff --git a/test/runtime/samples/action/_config.js b/test/runtime/samples/action/_config.js
index 49ec4dd18c..b6bd59595f 100644
--- a/test/runtime/samples/action/_config.js
+++ b/test/runtime/samples/action/_config.js
@@ -3,18 +3,18 @@ export default {
 		<button>action</button>
 	`,
 
-	test(assert, component, target, window) {
+	async test(assert, component, target, window) {
 		const button = target.querySelector('button');
 		const eventEnter = new window.MouseEvent('mouseenter');
 		const eventLeave = new window.MouseEvent('mouseleave');
 
-		button.dispatchEvent(eventEnter);
+		await button.dispatchEvent(eventEnter);
 		assert.htmlEqual(target.innerHTML, `
 			<button>action</button>
 			<div class="tooltip">Perform an Action</div>
 		`);
 
-		button.dispatchEvent(eventLeave);
+		await button.dispatchEvent(eventLeave);
 		assert.htmlEqual(target.innerHTML, `
 			<button>action</button>
 		`);
diff --git a/test/runtime/samples/binding-indirect-computed/_config.js b/test/runtime/samples/binding-indirect-computed/_config.js
index 1ec6e14034..123c0d6319 100644
--- a/test/runtime/samples/binding-indirect-computed/_config.js
+++ b/test/runtime/samples/binding-indirect-computed/_config.js
@@ -11,14 +11,14 @@ export default {
 		</select>
 	`,
 
-	test(assert, component, target, window) {
+	async test(assert, component, target, window) {
 		const select = target.querySelector('select');
 		const options = target.querySelectorAll('option');
 
 		const change = new window.Event('change');
 
 		options[1].selected = true;
-		select.dispatchEvent(change);
+		await select.dispatchEvent(change);
 
 		assert.equal(component.selected.letter, 'B');
 		assert.htmlEqual(target.innerHTML, `
diff --git a/test/runtime/samples/binding-indirect/_config.js b/test/runtime/samples/binding-indirect/_config.js
index dd6c2be644..7419d5b10d 100644
--- a/test/runtime/samples/binding-indirect/_config.js
+++ b/test/runtime/samples/binding-indirect/_config.js
@@ -32,7 +32,7 @@ export default {
 		<p>shake it all about</p>
 	`,
 
-	test(assert, component, target, window) {
+	async test(assert, component, target, window) {
 		const input = target.querySelector('input');
 		const select = target.querySelector('select');
 		const options = target.querySelectorAll('option');
@@ -40,7 +40,7 @@ export default {
 		const change = new window.Event('change');
 
 		input.checked = true;
-		input.dispatchEvent(change);
+		await input.dispatchEvent(change);
 
 		assert.ok(component.tasks[0].done);
 		assert.htmlEqual(target.innerHTML, `
@@ -62,12 +62,12 @@ export default {
 		`);
 
 		options[1].selected = true;
-		select.dispatchEvent(change);
+		await select.dispatchEvent(change);
 		assert.equal(component.selected, tasks[1]);
 		assert.ok(!input.checked);
 
 		input.checked = true;
-		input.dispatchEvent(change);
+		await input.dispatchEvent(change);
 
 		assert.ok(component.tasks[1].done);
 		assert.htmlEqual(target.innerHTML, `
diff --git a/test/runtime/samples/binding-input-checkbox-group-outside-each/_config.js b/test/runtime/samples/binding-input-checkbox-group-outside-each/_config.js
index d48a511e86..5c7012246d 100644
--- a/test/runtime/samples/binding-input-checkbox-group-outside-each/_config.js
+++ b/test/runtime/samples/binding-input-checkbox-group-outside-each/_config.js
@@ -7,7 +7,7 @@ const values = [
 export default {
 	props: {
 		values,
-		selected: [ values[1] ]
+		selected: [values[1]]
 	},
 
 	html: `
@@ -25,18 +25,18 @@ export default {
 
 		<p>Beta</p>`,
 
-	test ( assert, component, target, window ) {
-		const inputs = target.querySelectorAll( 'input' );
-		assert.equal( inputs[0].checked, false );
-		assert.equal( inputs[1].checked, true );
-		assert.equal( inputs[2].checked, false );
+	async test(assert, component, target, window) {
+		const inputs = target.querySelectorAll('input');
+		assert.equal(inputs[0].checked, false);
+		assert.equal(inputs[1].checked, true);
+		assert.equal(inputs[2].checked, false);
 
-		const event = new window.Event( 'change' );
+		const event = new window.Event('change');
 
 		inputs[0].checked = true;
-		inputs[0].dispatchEvent( event );
+		await inputs[0].dispatchEvent(event);
 
-		assert.htmlEqual( target.innerHTML, `
+		assert.htmlEqual(target.innerHTML, `
 			<label>
 				<input type="checkbox" value="[object Object]"> Alpha
 			</label>
@@ -50,14 +50,14 @@ export default {
 			</label>
 
 			<p>Alpha, Beta</p>
-		` );
+		`);
 
-		component.selected = [ values[1], values[2] ];
-		assert.equal( inputs[0].checked, false );
-		assert.equal( inputs[1].checked, true );
-		assert.equal( inputs[2].checked, true );
+		component.selected = [values[1], values[2]];
+		assert.equal(inputs[0].checked, false);
+		assert.equal(inputs[1].checked, true);
+		assert.equal(inputs[2].checked, true);
 
-		assert.htmlEqual( target.innerHTML, `
+		assert.htmlEqual(target.innerHTML, `
 			<label>
 				<input type="checkbox" value="[object Object]"> Alpha
 			</label>
@@ -71,6 +71,6 @@ export default {
 			</label>
 
 			<p>Beta, Gamma</p>
-		` );
+		`);
 	}
 };
diff --git a/test/runtime/samples/binding-input-checkbox-group/_config.js b/test/runtime/samples/binding-input-checkbox-group/_config.js
index d48a511e86..5c7012246d 100644
--- a/test/runtime/samples/binding-input-checkbox-group/_config.js
+++ b/test/runtime/samples/binding-input-checkbox-group/_config.js
@@ -7,7 +7,7 @@ const values = [
 export default {
 	props: {
 		values,
-		selected: [ values[1] ]
+		selected: [values[1]]
 	},
 
 	html: `
@@ -25,18 +25,18 @@ export default {
 
 		<p>Beta</p>`,
 
-	test ( assert, component, target, window ) {
-		const inputs = target.querySelectorAll( 'input' );
-		assert.equal( inputs[0].checked, false );
-		assert.equal( inputs[1].checked, true );
-		assert.equal( inputs[2].checked, false );
+	async test(assert, component, target, window) {
+		const inputs = target.querySelectorAll('input');
+		assert.equal(inputs[0].checked, false);
+		assert.equal(inputs[1].checked, true);
+		assert.equal(inputs[2].checked, false);
 
-		const event = new window.Event( 'change' );
+		const event = new window.Event('change');
 
 		inputs[0].checked = true;
-		inputs[0].dispatchEvent( event );
+		await inputs[0].dispatchEvent(event);
 
-		assert.htmlEqual( target.innerHTML, `
+		assert.htmlEqual(target.innerHTML, `
 			<label>
 				<input type="checkbox" value="[object Object]"> Alpha
 			</label>
@@ -50,14 +50,14 @@ export default {
 			</label>
 
 			<p>Alpha, Beta</p>
-		` );
+		`);
 
-		component.selected = [ values[1], values[2] ];
-		assert.equal( inputs[0].checked, false );
-		assert.equal( inputs[1].checked, true );
-		assert.equal( inputs[2].checked, true );
+		component.selected = [values[1], values[2]];
+		assert.equal(inputs[0].checked, false);
+		assert.equal(inputs[1].checked, true);
+		assert.equal(inputs[2].checked, true);
 
-		assert.htmlEqual( target.innerHTML, `
+		assert.htmlEqual(target.innerHTML, `
 			<label>
 				<input type="checkbox" value="[object Object]"> Alpha
 			</label>
@@ -71,6 +71,6 @@ export default {
 			</label>
 
 			<p>Beta, Gamma</p>
-		` );
+		`);
 	}
 };
diff --git a/test/runtime/samples/binding-input-checkbox-indeterminate/_config.js b/test/runtime/samples/binding-input-checkbox-indeterminate/_config.js
index 50a94d4564..cf50585fd9 100644
--- a/test/runtime/samples/binding-input-checkbox-indeterminate/_config.js
+++ b/test/runtime/samples/binding-input-checkbox-indeterminate/_config.js
@@ -11,7 +11,7 @@ export default {
 		<p>indeterminate? true</p>
 	`,
 
-	test(assert, component, target, window) {
+	async test(assert, component, target, window) {
 		const input = target.querySelector('input');
 		assert.equal(input.checked, false);
 		assert.equal(input.indeterminate, true);
@@ -20,7 +20,7 @@ export default {
 
 		input.checked = true;
 		input.indeterminate = false;
-		input.dispatchEvent(event);
+		await input.dispatchEvent(event);
 
 		assert.equal(component.indeterminate, false);
 		assert.equal(component.checked, true);
diff --git a/test/runtime/samples/binding-input-number/_config.js b/test/runtime/samples/binding-input-number/_config.js
index b209e8c201..91cc5ea88b 100644
--- a/test/runtime/samples/binding-input-number/_config.js
+++ b/test/runtime/samples/binding-input-number/_config.js
@@ -13,14 +13,14 @@ export default {
 		<p>number 42</p>
 	`,
 
-	test(assert, component, target, window) {
+	async test(assert, component, target, window) {
 		const input = target.querySelector('input');
 		assert.equal(input.value, '42');
 
 		const event = new window.Event('input');
 
 		input.value = '43';
-		input.dispatchEvent(event);
+		await input.dispatchEvent(event);
 
 		assert.equal(component.count, 43);
 		assert.htmlEqual(target.innerHTML, `
@@ -37,7 +37,7 @@ export default {
 
 		// empty string should be treated as undefined
 		input.value = '';
-		input.dispatchEvent(event);
+		await input.dispatchEvent(event);
 
 		assert.equal(component.count, undefined);
 		assert.htmlEqual(target.innerHTML, `
diff --git a/test/runtime/samples/event-handler-event-methods/_config.js b/test/runtime/samples/event-handler-event-methods/_config.js
index 33f2b3264b..c49dd0652e 100644
--- a/test/runtime/samples/event-handler-event-methods/_config.js
+++ b/test/runtime/samples/event-handler-event-methods/_config.js
@@ -1,12 +1,12 @@
 export default {
-	test ( assert, component, target, window ) {
-		const allow = target.querySelector( '.allow-propagation' );
-		const stop = target.querySelector( '.stop-propagation' );
+	test(assert, component, target, window) {
+		const allow = target.querySelector('.allow-propagation');
+		const stop = target.querySelector('.stop-propagation');
 
-		allow.dispatchEvent( new window.MouseEvent( 'click', { bubbles: true }) );
-		stop.dispatchEvent( new window.MouseEvent( 'click', { bubbles: true }) );
+		allow.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		stop.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
 
-		assert.equal( component.foo, true );
-		assert.equal( component.bar, false );
+		assert.equal(component.foo, true);
+		assert.equal(component.bar, false);
 	}
 };
diff --git a/test/runtime/samples/event-handler-hoisted/_config.js b/test/runtime/samples/event-handler-hoisted/_config.js
index 902541ae34..e8c33be3af 100644
--- a/test/runtime/samples/event-handler-hoisted/_config.js
+++ b/test/runtime/samples/event-handler-hoisted/_config.js
@@ -8,7 +8,7 @@ export default {
 		<button>click me</button>
 	`,
 
-	test (assert, component, target, window) {
+	test(assert, component, target, window) {
 		const button = target.querySelector('button');
 		const event = new window.MouseEvent('click');
 
diff --git a/test/runtime/samples/event-handler-this-methods/_config.js b/test/runtime/samples/event-handler-this-methods/_config.js
index 170ce46b0f..3692cab25b 100644
--- a/test/runtime/samples/event-handler-this-methods/_config.js
+++ b/test/runtime/samples/event-handler-this-methods/_config.js
@@ -1,16 +1,16 @@
 export default {
-	test ( assert, component, target, window ) {
+	test(assert, component, target, window) {
 		// Click events don't focus elements in JSDOM – obviously they would
 		// in real browsers. More realistically, you'd use this for e.g.
 		// this.select(), but that's harder to test than this.focus()
 
-		const wont = target.querySelector( '.wont-focus' );
-		const will = target.querySelector( '.will-focus' );
+		const wont = target.querySelector('.wont-focus');
+		const will = target.querySelector('.will-focus');
 
-		wont.dispatchEvent( new window.MouseEvent( 'click' ) );
-		assert.equal( window.document.activeElement, window.document.body );
+		wont.dispatchEvent(new window.MouseEvent('click'));
+		assert.equal(window.document.activeElement, window.document.body);
 
-		will.dispatchEvent( new window.MouseEvent( 'click' ) );
-		assert.equal( window.document.activeElement, will );
+		will.dispatchEvent(new window.MouseEvent('click'));
+		assert.equal(window.document.activeElement, will);
 	}
 };
diff --git a/test/runtime/samples/event-handler/_config.js b/test/runtime/samples/event-handler/_config.js
index 868fb362ae..6114ef346b 100644
--- a/test/runtime/samples/event-handler/_config.js
+++ b/test/runtime/samples/event-handler/_config.js
@@ -3,19 +3,19 @@ export default {
 		<button>toggle</button>
 	`,
 
-	test ( assert, component, target, window ) {
-		const button = target.querySelector( 'button' );
-		const event = new window.MouseEvent( 'click' );
+	async test(assert, component, target, window) {
+		const button = target.querySelector('button');
+		const event = new window.MouseEvent('click');
 
-		button.dispatchEvent( event );
-		assert.htmlEqual( target.innerHTML, `
+		await button.dispatchEvent(event);
+		assert.htmlEqual(target.innerHTML, `
 			<button>toggle</button>
 			<p>hello!</p>
-		` );
+		`);
 
-		button.dispatchEvent( event );
-		assert.htmlEqual( target.innerHTML, `
+		await button.dispatchEvent(event);
+		assert.htmlEqual(target.innerHTML, `
 			<button>toggle</button>
-		` );
+		`);
 	}
 };
diff --git a/test/runtime/samples/select-props/_config.js b/test/runtime/samples/select-props/_config.js
index 39ba26a49f..dcb572e7c6 100644
--- a/test/runtime/samples/select-props/_config.js
+++ b/test/runtime/samples/select-props/_config.js
@@ -1,15 +1,15 @@
 export default {
-	test ( assert, component, target, window ) {
-		const selects = document.querySelectorAll( 'select' );
+	test(assert, component, target, window) {
+		const selects = document.querySelectorAll('select');
 
-		const event1 = new window.Event( 'change' );
+		const event1 = new window.Event('change');
 		selects[0].value = 'b';
 		selects[0].dispatchEvent(event1);
 
-		const event2 = new window.Event( 'change' );
+		const event2 = new window.Event('change');
 		selects[1].value = 'b';
 		selects[1].dispatchEvent(event2);
 
-		assert.deepEqual( component.log, [ 1, 2 ] );
+		assert.deepEqual(component.log, [1, 2]);
 	}
 };
diff --git a/test/runtime/samples/spread-component-with-bind/_config.js b/test/runtime/samples/spread-component-with-bind/_config.js
index 06476712af..81dae69ea7 100644
--- a/test/runtime/samples/spread-component-with-bind/_config.js
+++ b/test/runtime/samples/spread-component-with-bind/_config.js
@@ -9,11 +9,11 @@ export default {
 		<input value=foo>
 	`,
 
-	test (assert, component, target, window) {
+	async test(assert, component, target, window) {
 		const input = target.querySelector('input');
 
 		input.value = 'bar';
-		input.dispatchEvent(new window.Event('input'));
+		await input.dispatchEvent(new window.Event('input'));
 
 		assert.htmlEqual(target.innerHTML, `
 			<p>bar</p>
diff --git a/test/runtime/samples/window-binding-resize/_config.js b/test/runtime/samples/window-binding-resize/_config.js
index 247fe59fdd..bba2be71eb 100644
--- a/test/runtime/samples/window-binding-resize/_config.js
+++ b/test/runtime/samples/window-binding-resize/_config.js
@@ -2,15 +2,15 @@ export default {
 	html: `<div>1024x768</div>`,
 
 	skip: true, // some weird stuff happening with JSDOM 11
-	// skip: /^v4/.test( process.version ), // node 4 apparently does some dumb stuff
+	// skip: /^v4/.test(process.version), // node 4 apparently does some dumb stuff
 	'skip-ssr': true, // there's some kind of weird bug with this test... it compiles with the wrong require.extensions hook for some bizarre reason
 
-	test ( assert, component, target, window ) {
-		const event = new window.Event( 'resize' );
+	async test(assert, component, target, window) {
+		const event = new window.Event('resize');
 
 		// JSDOM executes window event listeners with `global` rather than
 		// `window` (bug?) so we need to do this
-		Object.defineProperties( global, {
+		Object.defineProperties(global, {
 			innerWidth: {
 				value: 567,
 				configurable: true
@@ -21,9 +21,9 @@ export default {
 			}
 		});
 
-		window.dispatchEvent( event );
+		await window.dispatchEvent(event);
 
-		assert.htmlEqual( target.innerHTML, `
+		assert.htmlEqual(target.innerHTML, `
 			<div>567x456</div>
 		`);
 	}
diff --git a/test/runtime/samples/window-event-custom/_config.js b/test/runtime/samples/window-event-custom/_config.js
index a615482f92..7ecccfa74b 100644
--- a/test/runtime/samples/window-event-custom/_config.js
+++ b/test/runtime/samples/window-event-custom/_config.js
@@ -1,12 +1,12 @@
 export default {
 	html: `<p>escaped: false</p>`,
 
-	test(assert, component, target, window) {
+	async test(assert, component, target, window) {
 		const event = new window.KeyboardEvent('keydown', {
 			which: 27
 		});
 
-		window.dispatchEvent(event);
+		await window.dispatchEvent(event);
 
 		assert.htmlEqual(target.innerHTML, `
 			<p>escaped: true</p>
diff --git a/test/runtime/samples/window-event/_config.js b/test/runtime/samples/window-event/_config.js
index f8596defb1..797e1bab8f 100644
--- a/test/runtime/samples/window-event/_config.js
+++ b/test/runtime/samples/window-event/_config.js
@@ -2,15 +2,15 @@ export default {
 	html: `<div>undefinedxundefined</div>`,
 
 	skip: true, // some weird stuff happening with JSDOM 11
-	// skip: /^v4/.test( process.version ), // node 4 apparently does some dumb stuff
+	// skip: /^v4/.test(process.version), // node 4 apparently does some dumb stuff
 	'skip-ssr': true, // there's some kind of weird bug with this test... it compiles with the wrong require.extensions hook for some bizarre reason
 
-	test ( assert, component, target, window ) {
-		const event = new window.Event( 'resize' );
+	async test(assert, component, target, window) {
+		const event = new window.Event('resize');
 
 		// JSDOM executes window event listeners with `global` rather than
 		// `window` (bug?) so we need to do this
-		Object.defineProperties( global, {
+		Object.defineProperties(global, {
 			innerWidth: {
 				value: 567,
 				configurable: true
@@ -21,9 +21,9 @@ export default {
 			}
 		});
 
-		window.dispatchEvent( event );
+		await window.dispatchEvent(event);
 
-		assert.htmlEqual( target.innerHTML, `
+		assert.htmlEqual(target.innerHTML, `
 			<div>567x456</div>
 		`);
 	}