fix: improve namespace inference when having `{@render}` and `{@html}` tags (#10631)

* fix: treat snippets like normal components when inferring namespace

* n

* simplify

* better desc

* slight adjustment

* feedback

Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>

* feedback

Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>

* skip html tag

* test

* changeset name

* cleanup

---------

Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>

.changeset/giant-planets-shake.md

@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+fix: improve namespace inference when having `{@render}` and `{@html}` tags

packages/svelte/src/compiler/phases/3-transform/utils.js

@@ -5,6 +5,7 @@ import {
 	regex_whitespaces_strict
 } from '../patterns.js';
 import * as b from '../../utils/builders.js';
+import { walk } from 'zimmerframe';
 
 /**
  * @param {string} s
@@ -249,51 +250,49 @@ export function infer_namespace(namespace, parent, nodes, path) {
  * @param {import('#compiler').Namespace | 'keep' | 'maybe_html'} namespace
  */
 function check_nodes_for_namespace(nodes, namespace) {
+	/**
+	 * @param {import('#compiler').SvelteElement | import('#compiler').RegularElement} node}
+	 * @param {{stop: () => void}} context
+	 */
+	const RegularElement = (node, { stop }) => {
+		if (!node.metadata.svg) {
+			namespace = 'html';
+			stop();
+		} else if (namespace === 'keep') {
+			namespace = 'svg';
+		}
+	};
+
 	for (const node of nodes) {
-		if (node.type === 'RegularElement' || node.type === 'SvelteElement') {
-			if (!node.metadata.svg) {
-				namespace = 'html';
-				break;
-			} else if (namespace === 'keep') {
-				namespace = 'svg';
-			}
-		} else if (
-			(node.type === 'Text' && node.data.trim() !== '') ||
-			node.type === 'HtmlTag' ||
-			node.type === 'RenderTag'
-		) {
-			namespace = 'maybe_html';
-		} else if (node.type === 'EachBlock') {
-			namespace = check_nodes_for_namespace(node.body.nodes, namespace);
-			if (namespace === 'html') break;
-			if (node.fallback) {
-				namespace = check_nodes_for_namespace(node.fallback.nodes, namespace);
-				if (namespace === 'html') break;
-			}
-		} else if (node.type === 'IfBlock') {
-			namespace = check_nodes_for_namespace(node.consequent.nodes, namespace);
-			if (namespace === 'html') break;
-			if (node.alternate) {
-				namespace = check_nodes_for_namespace(node.alternate.nodes, namespace);
-				if (namespace === 'html') break;
-			}
-		} else if (node.type === 'AwaitBlock') {
-			if (node.pending) {
-				namespace = check_nodes_for_namespace(node.pending.nodes, namespace);
-				if (namespace === 'html') break;
+		walk(
+			node,
+			{},
+			{
+				_(node, { next }) {
+					if (
+						node.type === 'EachBlock' ||
+						node.type === 'IfBlock' ||
+						node.type === 'AwaitBlock' ||
+						node.type === 'Fragment' ||
+						node.type === 'KeyBlock' ||
+						node.type === 'RegularElement' ||
+						node.type === 'SvelteElement' ||
+						node.type === 'Text'
+					) {
+						next();
+					}
+				},
+				SvelteElement: RegularElement,
+				RegularElement,
+				Text(node) {
+					if (node.data.trim() !== '') {
+						namespace = 'maybe_html';
+					}
+				}
 			}
-			if (node.then) {
-				namespace = check_nodes_for_namespace(node.then.nodes, namespace);
-				if (namespace === 'html') break;
-			}
-			if (node.catch) {
-				namespace = check_nodes_for_namespace(node.catch.nodes, namespace);
-				if (namespace === 'html') break;
-			}
-		} else if (node.type === 'KeyBlock') {
-			namespace = check_nodes_for_namespace(node.fragment.nodes, namespace);
-			if (namespace === 'html') break;
-		}
+		);
+
+		if (namespace === 'html') return namespace;
 	}
 
 	return namespace;

packages/svelte/tests/runtime-runes/samples/svg-namespace-infer/Wrapper.svelte

@@ -2,12 +2,18 @@
 
 {#if true}
   <text x="0" y="26">true</text>
-{:else}
-  <text x="0" y="26">false</text>
 {/if}
 
-{#each  Array(3).fill(0) as item, idx}
+{#each Array(2).fill(0) as item, idx}
   <text x={idx * 10} y={42}>{idx}</text>
 {/each}
 
-<!-- comment should not set infer html namespace -->
+{@html '<text x="0" y="40">html</text>'}
+
+{@render test("snippet")}
+
+{#snippet test(text)}
+<text x={20} y={42}>{text}</text>
+{/snippet}
+
+<!-- comment should not infer html namespace -->

packages/svelte/tests/runtime-runes/samples/svg-namespace-infer/_config.js

@@ -7,7 +7,8 @@ export default test({
 		<text x="0" y="26">true</text>
 		<text x="0" y="42">0</text>
 		<text x="10" y="42">1</text>
-		<text x="20" y="42">2</text>
+		<text x="0" y="40">html</text>
+		<text x="20" y="42">snippet</text>
 	</svg>
 `,
 	test({ assert, target }) {
@@ -18,7 +19,7 @@ export default test({
 
 		const text_elements = target.querySelectorAll('text');
 
-		assert.equal(text_elements.length, 5);
+		assert.equal(text_elements.length, 6);
 
 		for (const { namespaceURI } of text_elements)
 			assert.equal(namespaceURI, 'http://www.w3.org/2000/svg');