From be3a8a82fbb22cc3ae1d54aa80c2418bdbb02a79 Mon Sep 17 00:00:00 2001
From: Simon Holthausen <simon.holthausen@vercel.com>
Date: Wed, 15 May 2024 12:04:21 +0200
Subject: [PATCH 1/3] feat: error on imports to `svelte/internal/*`

closes #11622
---
 .changeset/eight-carrots-hunt.md                       |  5 +++++
 packages/svelte/messages/compile-errors/script.md      |  4 ++++
 packages/svelte/src/compiler/errors.js                 |  9 +++++++++
 .../svelte/src/compiler/phases/2-analyze/validation.js | 10 ++++++++++
 .../samples/svelte-internal-import/_config.js          |  9 +++++++++
 .../samples/svelte-internal-import/main.svelte         |  5 +++++
 .../samples/svelte-internal-import/main.svelte.js      |  1 +
 7 files changed, 43 insertions(+)
 create mode 100644 .changeset/eight-carrots-hunt.md
 create mode 100644 packages/svelte/tests/compiler-errors/samples/svelte-internal-import/_config.js
 create mode 100644 packages/svelte/tests/compiler-errors/samples/svelte-internal-import/main.svelte
 create mode 100644 packages/svelte/tests/compiler-errors/samples/svelte-internal-import/main.svelte.js

diff --git a/.changeset/eight-carrots-hunt.md b/.changeset/eight-carrots-hunt.md
new file mode 100644
index 000000000000..a220e13080e7
--- /dev/null
+++ b/.changeset/eight-carrots-hunt.md
@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+feat: error on imports to `svelte/internal/*`
diff --git a/packages/svelte/messages/compile-errors/script.md b/packages/svelte/messages/compile-errors/script.md
index 861ac2f56d39..dbce3403d41a 100644
--- a/packages/svelte/messages/compile-errors/script.md
+++ b/packages/svelte/messages/compile-errors/script.md
@@ -46,6 +46,10 @@
 
 > `$host()` can only be used inside custom element component instances
 
+## import_svelte_internal_forbidden
+
+> Imports of `svelte/internal/*` are forbidden. It contains private runtime code which is subject to change without notice. If you're importing from `svelte/internal/*` to work around a limitation of Svelte, please open an issue at https://github.com/sveltejs/svelte and explain your use case
+
 ## legacy_export_invalid
 
 > Cannot use `export let` in runes mode — use `$props()` instead
diff --git a/packages/svelte/src/compiler/errors.js b/packages/svelte/src/compiler/errors.js
index ab7197b06b8d..f6da8165fbf2 100644
--- a/packages/svelte/src/compiler/errors.js
+++ b/packages/svelte/src/compiler/errors.js
@@ -404,6 +404,15 @@ export function store_invalid_subscription(node) {
 	e(node, "store_invalid_subscription", "Cannot reference store value inside `<script context=\"module\">`");
 }
 
+/**
+ * Imports of `svelte/internal/*` are forbidden. It contains private runtime code which is subject to change without notice. If you're importing from `svelte/internal/*` to work around a limitation of Svelte, please open an issue at https://github.com/sveltejs/svelte and explain your use case
+ * @param {null | number | NodeLike} node
+ * @returns {never}
+ */
+export function import_svelte_internal_forbidden(node) {
+	e(node, "import_svelte_internal_forbidden", "Imports of `svelte/internal/*` are forbidden. It contains private runtime code which is subject to change without notice. If you're importing from `svelte/internal/*` to work around a limitation of Svelte, please open an issue at https://github.com/sveltejs/svelte and explain your use case");
+}
+
 /**
  * Declaration cannot be empty
  * @param {null | number | NodeLike} node
diff --git a/packages/svelte/src/compiler/phases/2-analyze/validation.js b/packages/svelte/src/compiler/phases/2-analyze/validation.js
index 2c0296d69b48..a6f470630224 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/validation.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/validation.js
@@ -905,6 +905,11 @@ function ensure_no_module_import_conflict(node, state) {
  * @type {import('zimmerframe').Visitors<import('#compiler').SvelteNode, import('./types.js').AnalysisState>}
  */
 export const validation_runes_js = {
+	ImportDeclaration(node) {
+		if (typeof node.source.value === 'string' && node.source.value.startsWith('svelte/internal/')) {
+			e.import_svelte_internal_forbidden(node);
+		}
+	},
 	ExportSpecifier(node, { state }) {
 		validate_export(node, state.scope, node.local.name);
 	},
@@ -1077,6 +1082,11 @@ function validate_assignment(node, argument, state) {
 }
 
 export const validation_runes = merge(validation, a11y_validators, {
+	ImportDeclaration(node) {
+		if (typeof node.source.value === 'string' && node.source.value.startsWith('svelte/internal/')) {
+			e.import_svelte_internal_forbidden(node);
+		}
+	},
 	Identifier(node, { path, state }) {
 		let i = path.length;
 		let parent = /** @type {import('estree').Expression} */ (path[--i]);
diff --git a/packages/svelte/tests/compiler-errors/samples/svelte-internal-import/_config.js b/packages/svelte/tests/compiler-errors/samples/svelte-internal-import/_config.js
new file mode 100644
index 000000000000..731d23308ef1
--- /dev/null
+++ b/packages/svelte/tests/compiler-errors/samples/svelte-internal-import/_config.js
@@ -0,0 +1,9 @@
+import { test } from '../../test';
+
+export default test({
+	error: {
+		code: 'import_svelte_internal_forbidden',
+		message:
+			"Imports of `svelte/internal/*` are forbidden. It contains private runtime code which is subject to change without notice. If you're importing from `svelte/internal/*` to work around a limitation of Svelte, please open an issue at https://github.com/sveltejs/svelte and explain your use case"
+	}
+});
diff --git a/packages/svelte/tests/compiler-errors/samples/svelte-internal-import/main.svelte b/packages/svelte/tests/compiler-errors/samples/svelte-internal-import/main.svelte
new file mode 100644
index 000000000000..d31b8d0b7d51
--- /dev/null
+++ b/packages/svelte/tests/compiler-errors/samples/svelte-internal-import/main.svelte
@@ -0,0 +1,5 @@
+<svelte:options runes={true} />
+
+<script>
+    import { something } from 'svelte/internal/client';
+</script>
\ No newline at end of file
diff --git a/packages/svelte/tests/compiler-errors/samples/svelte-internal-import/main.svelte.js b/packages/svelte/tests/compiler-errors/samples/svelte-internal-import/main.svelte.js
new file mode 100644
index 000000000000..8047b01e681e
--- /dev/null
+++ b/packages/svelte/tests/compiler-errors/samples/svelte-internal-import/main.svelte.js
@@ -0,0 +1 @@
+import { something } from 'svelte/internal/server';

From 2afafea120a837aaa5cd8ca830f57589aab6981f Mon Sep 17 00:00:00 2001
From: Simon Holthausen <simon.holthausen@vercel.com>
Date: Wed, 15 May 2024 12:16:04 +0200
Subject: [PATCH 2/3] regenerate

---
 packages/svelte/src/compiler/errors.js | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/packages/svelte/src/compiler/errors.js b/packages/svelte/src/compiler/errors.js
index f6da8165fbf2..8a2832df1bd6 100644
--- a/packages/svelte/src/compiler/errors.js
+++ b/packages/svelte/src/compiler/errors.js
@@ -198,6 +198,15 @@ export function host_invalid_placement(node) {
 	e(node, "host_invalid_placement", "`$host()` can only be used inside custom element component instances");
 }
 
+/**
+ * Imports of `svelte/internal/*` are forbidden. It contains private runtime code which is subject to change without notice. If you're importing from `svelte/internal/*` to work around a limitation of Svelte, please open an issue at https://github.com/sveltejs/svelte and explain your use case
+ * @param {null | number | NodeLike} node
+ * @returns {never}
+ */
+export function import_svelte_internal_forbidden(node) {
+	e(node, "import_svelte_internal_forbidden", "Imports of `svelte/internal/*` are forbidden. It contains private runtime code which is subject to change without notice. If you're importing from `svelte/internal/*` to work around a limitation of Svelte, please open an issue at https://github.com/sveltejs/svelte and explain your use case");
+}
+
 /**
  * Cannot use `export let` in runes mode — use `$props()` instead
  * @param {null | number | NodeLike} node
@@ -404,15 +413,6 @@ export function store_invalid_subscription(node) {
 	e(node, "store_invalid_subscription", "Cannot reference store value inside `<script context=\"module\">`");
 }
 
-/**
- * Imports of `svelte/internal/*` are forbidden. It contains private runtime code which is subject to change without notice. If you're importing from `svelte/internal/*` to work around a limitation of Svelte, please open an issue at https://github.com/sveltejs/svelte and explain your use case
- * @param {null | number | NodeLike} node
- * @returns {never}
- */
-export function import_svelte_internal_forbidden(node) {
-	e(node, "import_svelte_internal_forbidden", "Imports of `svelte/internal/*` are forbidden. It contains private runtime code which is subject to change without notice. If you're importing from `svelte/internal/*` to work around a limitation of Svelte, please open an issue at https://github.com/sveltejs/svelte and explain your use case");
-}
-
 /**
  * Declaration cannot be empty
  * @param {null | number | NodeLike} node

From d2ed623f9c1a0108654533140520fbe0d1e3faaa Mon Sep 17 00:00:00 2001
From: Simon Holthausen <simon.holthausen@vercel.com>
Date: Wed, 15 May 2024 16:07:10 +0200
Subject: [PATCH 3/3] also error on svelte/internal

---
 packages/svelte/src/compiler/phases/2-analyze/validation.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/svelte/src/compiler/phases/2-analyze/validation.js b/packages/svelte/src/compiler/phases/2-analyze/validation.js
index a6f470630224..306a9d20e2a2 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/validation.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/validation.js
@@ -906,7 +906,7 @@ function ensure_no_module_import_conflict(node, state) {
  */
 export const validation_runes_js = {
 	ImportDeclaration(node) {
-		if (typeof node.source.value === 'string' && node.source.value.startsWith('svelte/internal/')) {
+		if (typeof node.source.value === 'string' && node.source.value.startsWith('svelte/internal')) {
 			e.import_svelte_internal_forbidden(node);
 		}
 	},
@@ -1083,7 +1083,7 @@ function validate_assignment(node, argument, state) {
 
 export const validation_runes = merge(validation, a11y_validators, {
 	ImportDeclaration(node) {
-		if (typeof node.source.value === 'string' && node.source.value.startsWith('svelte/internal/')) {
+		if (typeof node.source.value === 'string' && node.source.value.startsWith('svelte/internal')) {
 			e.import_svelte_internal_forbidden(node);
 		}
 	},