[fix] Fix different transition behavior between 3.49.0 and 3.50.0

src/runtime/internal/dom.ts

@@ -154,7 +154,13 @@ export function get_root_for_style(node: Node): ShadowRoot | Document {
 	return node.ownerDocument;
 }
 
-export function append_stylesheet(node: ShadowRoot | Document, style: HTMLStyleElement) {
+export function append_empty_stylesheet(node: Node) {
+	const style_element = element('style') as HTMLStyleElement;
+	append_stylesheet(get_root_for_style(node), style_element);
+	return style_element.sheet as CSSStyleSheet;
+}
+
+function append_stylesheet(node: ShadowRoot | Document, style: HTMLStyleElement) {
 	append((node as Document).head || node, style);
 	return style.sheet as CSSStyleSheet;
 }

src/runtime/internal/style_manager.ts

@@ -1,8 +1,8 @@
-import { append_stylesheet, detach, element, get_root_for_style } from './dom';
+import { append_empty_stylesheet, detach, get_root_for_style } from './dom';
 import { raf } from './environment';
 
 interface StyleInformation {
-	style_element: HTMLStyleElement;
+	stylesheet: CSSStyleSheet;
 	rules: Record<string, true>;
 }
 
@@ -20,8 +20,8 @@ function hash(str: string) {
 	return hash >>> 0;
 }
 
-function create_style_information(doc: Document | ShadowRoot) {
-	const info = { style_element: element('style'), rules: {} };
+function create_style_information(doc: Document | ShadowRoot, node: Element & ElementCSSInlineStyle) {
+	const info = { stylesheet: append_empty_stylesheet(node), rules: {} };
 	managed_styles.set(doc, info);
 	return info;
 }
@@ -39,10 +39,9 @@ export function create_rule(node: Element & ElementCSSInlineStyle, a: number, b:
 	const name = `__svelte_${hash(rule)}_${uid}`;
 	const doc = get_root_for_style(node);
 
-	const { style_element, rules } = managed_styles.get(doc) || create_style_information(doc);
+	const { stylesheet, rules } = managed_styles.get(doc) || create_style_information(doc, node);
 
 	if (!rules[name]) {
-		const stylesheet = append_stylesheet(doc, style_element);
 		rules[name] = true;
 		stylesheet.insertRule(`@keyframes ${name} ${rule}`, stylesheet.cssRules.length);
 	}
@@ -72,8 +71,9 @@ export function clear_rules() {
 	raf(() => {
 		if (active) return;
 		managed_styles.forEach(info => {
-			const { style_element } = info;
-			detach(style_element);
+			const { ownerNode } = info.stylesheet;
+			// there is no ownerNode if it runs on jsdom.
+			if (ownerNode) detach(ownerNode);
 		});
 		managed_styles.clear();
 	});

test/runtime-puppeteer/index.ts

@@ -117,8 +117,12 @@ describe('runtime (puppeteer)', function() {
 						load(id) {
 							if (id === 'main') {
 								return `
-									import SvelteComponent from ${JSON.stringify(path.join(__dirname, 'samples', dir, 'main.svelte'))};
-									import config from ${JSON.stringify(path.join(__dirname, 'samples', dir, '_config.js'))};
+									import SvelteComponent from ${JSON.stringify(
+										path.join(__dirname, 'samples', dir, 'main.svelte')
+									)};
+									import config from ${JSON.stringify(
+										path.join(__dirname, 'samples', dir, '_config.js')
+									)};
 									import * as assert from 'assert';
 
 									export default async function (target) {
@@ -140,6 +144,14 @@ describe('runtime (puppeteer)', function() {
 
 											const component = new SvelteComponent(options);
 
+											const waitUntil = async (fn, ms = 500) => {
+												const start = new Date().getTime();
+												do {
+													if (fn()) return;
+													await new Promise(resolve => window.setTimeout(resolve, 1));
+												} while (new Date().getTime() <= start + ms);
+											};
+
 											if (config.html) {
 												assert.htmlEqual(target.innerHTML, config.html);
 											}
@@ -150,6 +162,7 @@ describe('runtime (puppeteer)', function() {
 													component,
 													target,
 													window,
+													waitUntil,
 												});
 
 												component.$destroy();

test/runtime-puppeteer/samples/style_manager-cleanup/_config.js

@@ -0,0 +1,17 @@
+export default {
+	skip_if_ssr: true,
+	skip_if_hydrate: true,
+	skip_if_hydrate_from_ssr: true,
+	test: async ({ component, assert, window, waitUntil }) => {
+		assert.htmlEqual(window.document.head.innerHTML, '');
+		component.visible = true;
+		assert.htmlEqual(window.document.head.innerHTML, '<style></style>');
+		await waitUntil(() => window.document.head.innerHTML === '');
+		assert.htmlEqual(window.document.head.innerHTML, '');
+
+		component.visible = false;
+		assert.htmlEqual(window.document.head.innerHTML, '<style></style>');
+		await waitUntil(() => window.document.head.innerHTML === '');
+		assert.htmlEqual(window.document.head.innerHTML, '');
+	}
+};

test/runtime-puppeteer/samples/style_manager-cleanup/main.svelte

@@ -0,0 +1,16 @@
+<script>
+	export let visible;
+
+	function foo() {
+		return {
+			duration: 10,
+			css: t => {
+				return `opacity: ${t}`;
+			}
+		};
+	}
+</script>
+
+{#if visible}
+	<div transition:foo></div>
+{/if}

test/runtime-puppeteer/samples/transition-css-out-in/_config.js

@@ -0,0 +1,14 @@
+export default {
+	test: async ({ assert, component, window, waitUntil }) => {
+		component.visible = true;
+		await waitUntil(() => window.document.head.querySelector('style').sheet.rules.length === 2);
+		assert.equal(window.document.head.querySelector('style').sheet.rules.length, 2);
+		await waitUntil(() => window.document.head.querySelector('style') === null);
+		assert.equal(window.document.head.querySelector('style'), null);
+		component.visible = false;
+		await waitUntil(() => window.document.head.querySelector('style').sheet.rules.length === 2);
+		assert.equal(window.document.head.querySelector('style').sheet.rules.length, 2);
+		await waitUntil(() => window.document.head.querySelector('style') === null);
+		assert.equal(window.document.head.querySelector('style'), null);
+	}
+};

test/runtime-puppeteer/samples/transition-css-out-in/main.svelte

@@ -0,0 +1,20 @@
+<script>
+	export let visible;
+
+	function foo() {
+		return {
+			duration: 10,
+			css: t => {
+				return `opacity: ${t}`;
+			}
+		};
+	}
+</script>
+
+{#if visible}
+	<div transition:foo></div>
+{/if}
+
+{#if !visible}
+	<div transition:foo></div>
+{/if}