From ade66c6feade92cfd932dcb4be2812305e518d2b Mon Sep 17 00:00:00 2001
From: Paolo Ricciuti <ricciutipaolo@gmail.com>
Date: Fri, 21 Mar 2025 15:21:40 +0100
Subject: [PATCH] fix: use `get` in constructor for deriveds (#15300)
Co-authored-by: Rich Harris <rich.harris@vercel.com>
---
.changeset/new-cherries-leave.md | 5 +++++
.../client/visitors/MemberExpression.js | 4 +++-
.../samples/deriveds-in-constructor/_config.js | 5 +++++
.../deriveds-in-constructor/main.svelte | 18 ++++++++++++++++++
4 files changed, 31 insertions(+), 1 deletion(-)
create mode 100644 .changeset/new-cherries-leave.md
create mode 100644 packages/svelte/tests/runtime-runes/samples/deriveds-in-constructor/_config.js
create mode 100644 packages/svelte/tests/runtime-runes/samples/deriveds-in-constructor/main.svelte
diff --git a/.changeset/new-cherries-leave.md b/.changeset/new-cherries-leave.md
new file mode 100644
index 0000000000..738a78b4a3
--- /dev/null
+++ b/.changeset/new-cherries-leave.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: use `get` in constructor for deriveds
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/MemberExpression.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/MemberExpression.js
index 501ecda555..3f2aada1f5 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/MemberExpression.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/MemberExpression.js
@@ -11,7 +11,9 @@ export function MemberExpression(node, context) {
if (node.property.type === 'PrivateIdentifier') {
const field = context.state.private_state.get(node.property.name);
if (field) {
- return context.state.in_constructor ? b.member(node, 'v') : b.call('$.get', node);
+ return context.state.in_constructor && (field.kind === 'raw_state' || field.kind === 'state')
+ ? b.member(node, 'v')
+ : b.call('$.get', node);
}
}
diff --git a/packages/svelte/tests/runtime-runes/samples/deriveds-in-constructor/_config.js b/packages/svelte/tests/runtime-runes/samples/deriveds-in-constructor/_config.js
new file mode 100644
index 0000000000..b364a989f4
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/deriveds-in-constructor/_config.js
@@ -0,0 +1,5 @@
+import { test } from '../../test';
+
+export default test({
+ html: `<p>state,derived state,derived.by derived state</p>`
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/deriveds-in-constructor/main.svelte b/packages/svelte/tests/runtime-runes/samples/deriveds-in-constructor/main.svelte
new file mode 100644
index 0000000000..bc8efba7e7
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/deriveds-in-constructor/main.svelte
@@ -0,0 +1,18 @@
+<script>
+ class Foo {
+ #state = $state('state')
+ #derived = $derived('derived ' + this.#state);
+ #derivedBy = $derived.by(() => {
+ return 'derived.by ' + this.#derived
+ });
+
+ initial
+
+ constructor() {
+ this.initial = [this.#state, this.#derived, this.#derivedBy]
+ }
+ }
+ const foo = new Foo()
+</script>
+
+<p>{foo.initial}</p>
\ No newline at end of file