add test for transitions on nested components

test/runtime/samples/transition-js-nested-intro/_config.js

@@ -0,0 +1,21 @@
+export default {
+	test ( assert, component, target, window, raf ) {
+		component.set({ visible: true });
+		const div = target.querySelector( 'div' );
+		assert.equal( div.foo, 0 );
+
+		raf.tick( 50 );
+		assert.equal( div.foo, 0 );
+
+		raf.tick( 100 );
+		assert.equal( div.foo, 0.5 );
+
+		raf.tick( 125 );
+		assert.equal( div.foo, 0.75 );
+
+		raf.tick( 150 );
+		assert.equal( div.foo, 1 );
+
+		component.destroy();
+	}
+};

test/runtime/samples/transition-js-nested-intro/child.html

@@ -0,0 +1,17 @@
+<div transition:foo><slot></slot></div>
+
+<script>
+	export default {
+		transitions: {
+			foo: function ( node, params ) {
+				return {
+					delay: 50,
+					duration: 100,
+					tick: t => {
+						node.foo = t;
+					}
+				};
+			}
+		}
+	};
+</script>

test/runtime/samples/transition-js-nested-intro/main.html

@@ -0,0 +1,10 @@
+{{#if visible}}
+	<Child>delayed</Child>
+{{/if}}
+
+<script>
+	import Child from './Child.html';
+	export default {
+		components:{ Child }
+	};
+</script>