From 28f3755e407032f811c85a591dd20208097eaffa Mon Sep 17 00:00:00 2001
From: Dominik G <dominik.goepel@gmx.de>
Date: Wed, 8 May 2024 14:13:50 +0200
Subject: [PATCH] fix: use acceptExports to support partial hmr (#11453)

* fix: use acceptExports to support partial hmr

* fix: add condition to only use acceptExports when it is available

* fix: update test snapshot

* fix: format
---
 .changeset/slimy-onions-approve.md            |  5 +++++
 .../3-transform/client/transform-client.js    | 20 +++++++++----------
 .../hmr/_expected/client/index.svelte.js      |  6 ++++--
 3 files changed, 19 insertions(+), 12 deletions(-)
 create mode 100644 .changeset/slimy-onions-approve.md

diff --git a/.changeset/slimy-onions-approve.md b/.changeset/slimy-onions-approve.md
new file mode 100644
index 0000000000..5fb6d305dc
--- /dev/null
+++ b/.changeset/slimy-onions-approve.md
@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+fix: use import.meta.hot.acceptExports when available to support partial hmr in vite
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/transform-client.js b/packages/svelte/src/compiler/phases/3-transform/client/transform-client.js
index a32f54ea78..5495f3f6be 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/transform-client.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/transform-client.js
@@ -429,6 +429,10 @@ export function client_component(source, analysis, options) {
 	);
 
 	if (options.hmr) {
+		const accept_fn = b.arrow(
+			[b.id('module')],
+			b.block([b.stmt(b.call('$.set', b.id('s'), b.member(b.id('module'), b.id('default'))))])
+		);
 		body.push(
 			component,
 			b.if(
@@ -436,16 +440,12 @@ export function client_component(source, analysis, options) {
 				b.block([
 					b.const(b.id('s'), b.call('$.source', b.id(analysis.name))),
 					b.stmt(b.assignment('=', b.id(analysis.name), b.call('$.hmr', b.id('s')))),
-					b.stmt(
-						b.call(
-							'import.meta.hot.accept',
-							b.arrow(
-								[b.id('module')],
-								b.block([
-									b.stmt(b.call('$.set', b.id('s'), b.member(b.id('module'), b.id('default'))))
-								])
-							)
-						)
+					b.if(
+						b.id('import.meta.hot.acceptExports'),
+						b.stmt(
+							b.call('import.meta.hot.acceptExports', b.array([b.literal('default')]), accept_fn)
+						),
+						b.stmt(b.call('import.meta.hot.accept', accept_fn))
 					)
 				])
 			),
diff --git a/packages/svelte/tests/snapshot/samples/hmr/_expected/client/index.svelte.js b/packages/svelte/tests/snapshot/samples/hmr/_expected/client/index.svelte.js
index f1c08f4ed8..46a18e0b2b 100644
--- a/packages/svelte/tests/snapshot/samples/hmr/_expected/client/index.svelte.js
+++ b/packages/svelte/tests/snapshot/samples/hmr/_expected/client/index.svelte.js
@@ -14,9 +14,11 @@ if (import.meta.hot) {
 
 	Hmr = $.hmr(s);
 
-	import.meta.hot.accept((module) => {
+	if (import.meta.hot.acceptExports) import.meta.hot.acceptExports(["default"], (module) => {
+		$.set(s, module.default);
+	}); else import.meta.hot.accept((module) => {
 		$.set(s, module.default);
 	});
 }
 
-export default Hmr;
\ No newline at end of file
+export default Hmr;