From e86da84c799d3c6d37dcabc513612015dff55e4b Mon Sep 17 00:00:00 2001
From: paoloricciuti <ricciutipaolo@gmail.com>
Date: Mon, 30 Mar 2026 11:24:52 +0200
Subject: [PATCH] fix: handle compiled `nodeValue`/`textContent`

---
 .../client/visitors/RegularElement.js         | 22 ++++++++++++++++---
 .../client/visitors/shared/fragment.js        |  7 +++++-
 .../_config.js                                |  5 +++++
 .../main.svelte                               |  5 +++++
 .../text-expression-standalone/_config.js     |  5 +++++
 .../text-expression-standalone/main.svelte    |  5 +++++
 6 files changed, 45 insertions(+), 4 deletions(-)
 create mode 100644 packages/svelte/tests/custom-renderers/samples/text-expression-standalone-element/_config.js
 create mode 100644 packages/svelte/tests/custom-renderers/samples/text-expression-standalone-element/main.svelte
 create mode 100644 packages/svelte/tests/custom-renderers/samples/text-expression-standalone/_config.js
 create mode 100644 packages/svelte/tests/custom-renderers/samples/text-expression-standalone/main.svelte

diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/RegularElement.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/RegularElement.js
index ec74c3ed27..0746c5f867 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/RegularElement.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/RegularElement.js
@@ -346,9 +346,25 @@ export function RegularElement(node, context) {
 		const empty_string = value.type === 'Literal' && value.value === '';
 
 		if (!empty_string) {
-			child_state.init.push(
-				b.stmt(b.assignment('=', b.member(context.state.node, 'textContent'), value))
-			);
+			if (context.state.options.customRenderer) {
+				// custom renderers need to use the method to invoke the renderer
+				context.state.template.push_text([
+					{
+						type: 'Text',
+						data: '',
+						raw: '',
+						start: -1,
+						end: -1
+					}
+				]);
+				const text = context.state.scope.generate('text');
+				context.state.init.push(b.var(text, b.call('$.child', node_id)));
+				context.state.init.push(b.stmt(b.call('$.set_text', b.id(text), value)));
+			} else {
+				child_state.init.push(
+					b.stmt(b.assignment('=', b.member(context.state.node, 'textContent'), value))
+				);
+			}
 		}
 	} else if (is_customizable_select_element(node)) {
 		// For <option>, <optgroup>, or <select> elements with rich content, we need to branch based on browser support.
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/fragment.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/fragment.js
index f77af74f7e..d245665d78 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/fragment.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/fragment.js
@@ -83,7 +83,12 @@ export function process_children(nodes, initial, is_element, context) {
 		if (has_state && !within_bound_contenteditable) {
 			context.state.update.push(update);
 		} else {
-			context.state.init.push(b.stmt(b.assignment('=', b.member(id, 'nodeValue'), value)));
+			if (context.state.options.customRenderer) {
+				// custom renderers need to use the method to invoke the renderer
+				context.state.init.push(update);
+			} else {
+				context.state.init.push(b.stmt(b.assignment('=', b.member(id, 'nodeValue'), value)));
+			}
 		}
 	}
 
diff --git a/packages/svelte/tests/custom-renderers/samples/text-expression-standalone-element/_config.js b/packages/svelte/tests/custom-renderers/samples/text-expression-standalone-element/_config.js
new file mode 100644
index 0000000000..68e35f6a66
--- /dev/null
+++ b/packages/svelte/tests/custom-renderers/samples/text-expression-standalone-element/_config.js
@@ -0,0 +1,5 @@
+import { test } from '../../test';
+
+export default test({
+	html: '<p>hello world</p>'
+});
diff --git a/packages/svelte/tests/custom-renderers/samples/text-expression-standalone-element/main.svelte b/packages/svelte/tests/custom-renderers/samples/text-expression-standalone-element/main.svelte
new file mode 100644
index 0000000000..2d4188f2de
--- /dev/null
+++ b/packages/svelte/tests/custom-renderers/samples/text-expression-standalone-element/main.svelte
@@ -0,0 +1,5 @@
+<script>
+	let name = $state("world");
+</script>
+
+<p>hello {name}</p>
diff --git a/packages/svelte/tests/custom-renderers/samples/text-expression-standalone/_config.js b/packages/svelte/tests/custom-renderers/samples/text-expression-standalone/_config.js
new file mode 100644
index 0000000000..b5933e4424
--- /dev/null
+++ b/packages/svelte/tests/custom-renderers/samples/text-expression-standalone/_config.js
@@ -0,0 +1,5 @@
+import { test } from '../../test';
+
+export default test({
+	html: 'hello world'
+});
diff --git a/packages/svelte/tests/custom-renderers/samples/text-expression-standalone/main.svelte b/packages/svelte/tests/custom-renderers/samples/text-expression-standalone/main.svelte
new file mode 100644
index 0000000000..bc43d58894
--- /dev/null
+++ b/packages/svelte/tests/custom-renderers/samples/text-expression-standalone/main.svelte
@@ -0,0 +1,5 @@
+<script>
+	let name = $state("world");
+</script>
+
+hello {name}