outro when <svelte:component> switches - #1568

src/compile/nodes/Component.ts

@@ -1,6 +1,4 @@
 import deindent from '../../utils/deindent';
-import flattenReference from '../../utils/flattenReference';
-import validCalleeObjects from '../../utils/validCalleeObjects';
 import stringifyProps from '../../utils/stringifyProps';
 import CodeBuilder from '../../utils/CodeBuilder';
 import getTailSnippet from '../../utils/getTailSnippet';
@@ -10,7 +8,6 @@ import { escape, escapeTemplate, stringify } from '../../utils/stringify';
 import Node from './shared/Node';
 import Block from '../dom/Block';
 import Attribute from './Attribute';
-import usesThisOrArguments from '../../validate/js/utils/usesThisOrArguments';
 import mapChildren from './shared/mapChildren';
 import Binding from './Binding';
 import EventHandler from './EventHandler';
@@ -344,9 +341,7 @@ export default class Component extends Node {
 			const switch_value = block.getUniqueName('switch_value');
 			const switch_props = block.getUniqueName('switch_props');
 
-			const { dependencies, snippet } = this.expression;
+			const { snippet } = this.expression;
-
-			const anchor = this.getOrCreateAnchor(block, parentNode, parentNodes);
 
 			block.builders.init.addBlock(deindent`
 				var ${switch_value} = ${snippet};
@@ -392,6 +387,7 @@ export default class Component extends Node {
 				}
 			`);
 
+			const anchor = this.getOrCreateAnchor(block, parentNode, parentNodes);
 			const updateMountNode = this.getUpdateMountNode(anchor);
 
 			if (updates.length) {
@@ -402,7 +398,16 @@ export default class Component extends Node {
 
 			block.builders.update.addBlock(deindent`
 				if (${switch_value} !== (${switch_value} = ${snippet})) {
-					if (${name}) ${name}.destroy();
+					if (${name}) {
+						${this.compiler.options.nestedTransitions
+						? deindent`
+						@transitionManager.groupOutros();
+						const old_component = ${name};
+						old_component._fragment.o(() => {
+							old_component.destroy();
+						});`
+						: `${name}.destroy();`}
+					}
 
 					if (${switch_value}) {
 						${name} = new ${switch_value}(${switch_props}(ctx));

test/runtime/samples/transition-js-dynamic-component/A.html

@@ -0,0 +1,16 @@
+<div transition:a>a</div>
+
+<script>
+	export default {
+		transitions: {
+			a(node, params) {
+				return {
+					duration: 100,
+					tick: t => {
+						node.a = t;
+					}
+				};
+			}
+		}
+	};
+</script>

test/runtime/samples/transition-js-dynamic-component/B.html

@@ -0,0 +1,16 @@
+<div transition:b>b</div>
+
+<script>
+	export default {
+		transitions: {
+			b(node, params) {
+				return {
+					duration: 100,
+					tick: t => {
+						node.b = t;
+					}
+				};
+			}
+		}
+	};
+</script>

test/runtime/samples/transition-js-dynamic-component/_config.js

@@ -0,0 +1,37 @@
+export default {
+	nestedTransitions: true,
+	skipIntroByDefault: true,
+
+	data: {
+		x: true,
+	},
+
+	html: `
+		<div>a</div>
+	`,
+
+	test (assert, component, target, window, raf) {
+		component.set({ x: false });
+
+		assert.htmlEqual(target.innerHTML, `
+			<div>a</div>
+			<div>b</div>
+		`);
+
+		const [a, b] = target.querySelectorAll('div');
+
+		raf.tick(25);
+
+		assert.equal(a.a, 0.75);
+		assert.equal(b.b, 0.25);
+
+		raf.tick(100);
+
+		assert.equal(a.a, 0);
+		assert.equal(b.b, 1);
+
+		assert.htmlEqual(target.innerHTML, `
+			<div>b</div>
+		`);
+	}
+};

test/runtime/samples/transition-js-dynamic-component/main.html

@@ -0,0 +1,12 @@
+<svelte:component this="{x ? A : B}"/>
+
+<script>
+	import A from './A.html';
+	import B from './B.html';
+
+	export default {
+		data() {
+			return { A, B };
+		}
+	};
+</script>