From 9a28416aa36ca0426569b356810ee4e8de1b3d0b Mon Sep 17 00:00:00 2001
From: Tan Li Hau <lhtan93@gmail.com>
Date: Wed, 3 Mar 2021 09:23:18 +0800
Subject: [PATCH 01/18] should not extend scope for across slots

---
 src/compiler/compile/nodes/Slot.ts            | 22 -------------------
 .../Nested.svelte                             | 11 ++++++++++
 .../component-slot-default-in-each/_config.js |  7 ++++++
 .../main.svelte                               |  7 ++++++
 .../Nested.svelte                             |  2 --
 .../_config.js                                |  4 ++--
 6 files changed, 27 insertions(+), 26 deletions(-)
 create mode 100644 test/runtime/samples/component-slot-default-in-each/Nested.svelte
 create mode 100644 test/runtime/samples/component-slot-default-in-each/_config.js
 create mode 100644 test/runtime/samples/component-slot-default-in-each/main.svelte

diff --git a/src/compiler/compile/nodes/Slot.ts b/src/compiler/compile/nodes/Slot.ts
index c21a48f5d665..0ad5cc849e27 100644
--- a/src/compiler/compile/nodes/Slot.ts
+++ b/src/compiler/compile/nodes/Slot.ts
@@ -37,28 +37,6 @@ export default class Slot extends Element {
 
 		if (!this.slot_name) this.slot_name = 'default';
 
-		if (this.slot_name === 'default') {
-			// if this is the default slot, add our dependencies to any
-			// other slots (which inherit our slot values) that were
-			// previously encountered
-			component.slots.forEach((slot) => {
-				this.values.forEach((attribute, name) => {
-					if (!slot.values.has(name)) {
-						slot.values.set(name, attribute);
-					}
-				});
-			});
-		} else if (component.slots.has('default')) {
-			// otherwise, go the other way — inherit values from
-			// a previously encountered default slot
-			const default_slot = component.slots.get('default');
-			default_slot.values.forEach((attribute, name) => {
-				if (!this.values.has(name)) {
-					this.values.set(name, attribute);
-				}
-			});
-		}
-
 		component.slots.set(this.slot_name, this);
 	}
 }
diff --git a/test/runtime/samples/component-slot-default-in-each/Nested.svelte b/test/runtime/samples/component-slot-default-in-each/Nested.svelte
new file mode 100644
index 000000000000..d21684310196
--- /dev/null
+++ b/test/runtime/samples/component-slot-default-in-each/Nested.svelte
@@ -0,0 +1,11 @@
+<script>
+	let promise = new Promise(resolve => resolve(10));
+</script>
+
+{#each {length: 3} as _, i}
+	<slot item={i}/>
+{/each}
+
+{#await promise then value}
+	<slot {value}/>
+{/await}
diff --git a/test/runtime/samples/component-slot-default-in-each/_config.js b/test/runtime/samples/component-slot-default-in-each/_config.js
new file mode 100644
index 000000000000..5c0fd13871d5
--- /dev/null
+++ b/test/runtime/samples/component-slot-default-in-each/_config.js
@@ -0,0 +1,7 @@
+export default {
+	html: `
+		<div>0 - undefined</div>
+		<div>1 - undefined</div>
+		<div>2 - undefined</div>
+	`
+};
diff --git a/test/runtime/samples/component-slot-default-in-each/main.svelte b/test/runtime/samples/component-slot-default-in-each/main.svelte
new file mode 100644
index 000000000000..2ff707e04db3
--- /dev/null
+++ b/test/runtime/samples/component-slot-default-in-each/main.svelte
@@ -0,0 +1,7 @@
+<script>
+	import Nested from './Nested.svelte';
+</script>
+
+<Nested let:item let:value>
+	<div>{item} - {value}</div>
+</Nested>
\ No newline at end of file
diff --git a/test/runtime/samples/component-slot-named-inherits-default-lets/Nested.svelte b/test/runtime/samples/component-slot-named-inherits-default-lets/Nested.svelte
index 472af6278ea8..cecce8db0196 100644
--- a/test/runtime/samples/component-slot-named-inherits-default-lets/Nested.svelte
+++ b/test/runtime/samples/component-slot-named-inherits-default-lets/Nested.svelte
@@ -1,6 +1,4 @@
 <script>
-	import { onDestroy } from 'svelte';
-
 	let count = 0;
 
 	function increment() {
diff --git a/test/runtime/samples/component-slot-named-inherits-default-lets/_config.js b/test/runtime/samples/component-slot-named-inherits-default-lets/_config.js
index 8297162b91cd..dbfa8270af4f 100644
--- a/test/runtime/samples/component-slot-named-inherits-default-lets/_config.js
+++ b/test/runtime/samples/component-slot-named-inherits-default-lets/_config.js
@@ -3,7 +3,7 @@ export default {
 		<div>
 			<p>count in default slot: 0</p>
 			<p slot="foo">count in foo slot: 0</p>
-			<p slot="bar">count in bar slot: 0</p>
+			<p slot="bar">count in bar slot: undefined</p>
 			<button>+1</button>
 		</div>
 	`,
@@ -17,7 +17,7 @@ export default {
 			<div>
 				<p>count in default slot: 1</p>
 				<p slot="foo">count in foo slot: 1</p>
-				<p slot="bar">count in bar slot: 1</p>
+				<p slot="bar">count in bar slot: undefined</p>
 				<button>+1</button>
 			</div>
 		`);

From 2c41d2e377ddfd6628ab32960906568441341936 Mon Sep 17 00:00:00 2001
From: Tan Li Hau <lhtan93@gmail.com>
Date: Thu, 4 Mar 2021 09:50:39 +0800
Subject: [PATCH 02/18] disallow named slots inheriting let: scope from default
 slots

---
 src/compiler/compile/nodes/InlineComponent.ts | 37 ++++++-----
 .../wrappers/InlineComponent/index.ts         |  7 ---
 .../render_dom/wrappers/SlotTemplate.ts       |  5 --
 .../render_ssr/handlers/SlotTemplate.ts       |  6 --
 .../_config.js                                |  4 +-
 .../main.svelte                               |  1 +
 .../samples/lets-on-component/input.svelte    | 27 ++++++++
 .../samples/lets-on-component/warnings.json   | 62 +++++++++++++++++++
 8 files changed, 113 insertions(+), 36 deletions(-)
 create mode 100644 test/validator/samples/lets-on-component/input.svelte
 create mode 100644 test/validator/samples/lets-on-component/warnings.json

diff --git a/src/compiler/compile/nodes/InlineComponent.ts b/src/compiler/compile/nodes/InlineComponent.ts
index 8871c5f306dd..0b8c77049bec 100644
--- a/src/compiler/compile/nodes/InlineComponent.ts
+++ b/src/compiler/compile/nodes/InlineComponent.ts
@@ -5,7 +5,6 @@ import Binding from './Binding';
 import EventHandler from './EventHandler';
 import Expression from './shared/Expression';
 import Component from '../Component';
-import Let from './Let';
 import TemplateScope from './shared/TemplateScope';
 import { INode } from './interfaces';
 import { TemplateNode } from '../../interfaces';
@@ -18,7 +17,6 @@ export default class InlineComponent extends Node {
 	attributes: Attribute[] = [];
 	bindings: Binding[] = [];
 	handlers: EventHandler[] = [];
-	lets: Let[] = [];
 	css_custom_properties: Attribute[] = [];
 	children: INode[];
 	scope: TemplateScope;
@@ -40,6 +38,7 @@ export default class InlineComponent extends Node {
 			? new Expression(component, this, scope, info.expression)
 			: null;
 
+		const let_attributes = [];
 		info.attributes.forEach(node => {
 			/* eslint-disable no-fallthrough */
 			switch (node.type) {
@@ -68,7 +67,7 @@ export default class InlineComponent extends Node {
 					break;
 
 				case 'Let':
-					this.lets.push(new Let(component, this, scope, node));
+					let_attributes.push(node);
 					break;
 
 				case 'Transition':
@@ -83,19 +82,7 @@ export default class InlineComponent extends Node {
 			/* eslint-enable no-fallthrough */
 		});
 
-		if (this.lets.length > 0) {
-			this.scope = scope.child();
-
-			this.lets.forEach(l => {
-				const dependencies = new Set([l.name.name]);
-
-				l.names.forEach(name => {
-					this.scope.add(name, dependencies, this);
-				});
-			});
-		} else {
-			this.scope = scope;
-		}
+		this.scope = scope;
 
 		this.handlers.forEach(handler => {
 			handler.modifiers.forEach(modifier => {
@@ -156,6 +143,24 @@ export default class InlineComponent extends Node {
 			});
 		}
 
+		if (let_attributes.length) {
+			let warned = false;
+			// copy let: attribute from <Component /> to <svelte:fragment slot="default" />
+			// as they are for `slot="default"` only
+			children.forEach(child => {
+				const slot = child.attributes.find(attribute => attribute.name === 'slot');
+				if (!slot || slot.value[0].data === 'default') {
+					child.attributes.push(...let_attributes);
+				} else if (!warned) {
+					component.warn(info, {
+						code: 'let-on-component',
+						message: 'let: bindings on Component are meant for default slot template only, it is better to define them on <svelte:fragment slot="default"> instead.'
+					});
+					warned = true;
+				}
+			});
+		}
+
 		this.children = map_children(component, this, this.scope, children);
 	}
 
diff --git a/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts b/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts
index 37aaf2e7b26a..4f255483533d 100644
--- a/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts
+++ b/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts
@@ -14,7 +14,6 @@ import is_dynamic from '../shared/is_dynamic';
 import bind_this from '../shared/bind_this';
 import { Node, Identifier, ObjectExpression } from 'estree';
 import EventHandler from '../Element/EventHandler';
-import { extract_names } from 'periscopic';
 import mark_each_block_bindings from '../shared/mark_each_block_bindings';
 import { string_to_member_expression } from '../../../utils/string_to_member_expression';
 import SlotTemplate from '../../../nodes/SlotTemplate';
@@ -80,12 +79,6 @@ export default class InlineComponentWrapper extends Wrapper {
 		};
 
 		if (this.node.children.length) {
-			this.node.lets.forEach(l => {
-				extract_names(l.value || l.name).forEach(name => {
-					renderer.add_to_context(name, true);
-				});
-			});
-
 			this.children = this.node.children.map(child => new SlotTemplateWrapper(renderer, block, this, child as SlotTemplate, strip_whitespace, next_sibling));
 		}
 
diff --git a/src/compiler/compile/render_dom/wrappers/SlotTemplate.ts b/src/compiler/compile/render_dom/wrappers/SlotTemplate.ts
index a50f74fc04c8..1e040f0c5188 100644
--- a/src/compiler/compile/render_dom/wrappers/SlotTemplate.ts
+++ b/src/compiler/compile/render_dom/wrappers/SlotTemplate.ts
@@ -47,11 +47,6 @@ export default class SlotTemplateWrapper extends Wrapper {
 		});
 		this.renderer.blocks.push(this.block);
 
-		const seen = new Set(lets.map(l => l.name.name));
-		this.parent.node.lets.forEach(l => {
-			if (!seen.has(l.name.name)) lets.push(l);
-		});
-
 		this.parent.set_slot(
 			slot_template_name,
 			get_slot_definition(this.block, scope, lets)
diff --git a/src/compiler/compile/render_ssr/handlers/SlotTemplate.ts b/src/compiler/compile/render_ssr/handlers/SlotTemplate.ts
index 09f329330157..7d63fa27fdfe 100644
--- a/src/compiler/compile/render_ssr/handlers/SlotTemplate.ts
+++ b/src/compiler/compile/render_ssr/handlers/SlotTemplate.ts
@@ -14,12 +14,6 @@ export default function(node: SlotTemplate, renderer: Renderer, options: RenderO
 	renderer.push();
 	renderer.render(children, options);
 
-	const lets = node.lets;
-	const seen = new Set(lets.map(l => l.name.name));
-	parent_inline_component.lets.forEach(l => {
-		if (!seen.has(l.name.name)) lets.push(l);
-	});
-
 	const slot_fragment_content = renderer.pop();
 	if (!is_empty_template_literal(slot_fragment_content)) {
 		if (options.slot_scopes.has(node.slot_template_name)) {
diff --git a/test/runtime/samples/component-slot-named-inherits-default-lets/_config.js b/test/runtime/samples/component-slot-named-inherits-default-lets/_config.js
index dbfa8270af4f..80a67bfae1b2 100644
--- a/test/runtime/samples/component-slot-named-inherits-default-lets/_config.js
+++ b/test/runtime/samples/component-slot-named-inherits-default-lets/_config.js
@@ -3,7 +3,7 @@ export default {
 		<div>
 			<p>count in default slot: 0</p>
 			<p slot="foo">count in foo slot: 0</p>
-			<p slot="bar">count in bar slot: undefined</p>
+			<p slot="bar">count in bar slot: 42</p>
 			<button>+1</button>
 		</div>
 	`,
@@ -17,7 +17,7 @@ export default {
 			<div>
 				<p>count in default slot: 1</p>
 				<p slot="foo">count in foo slot: 1</p>
-				<p slot="bar">count in bar slot: undefined</p>
+				<p slot="bar">count in bar slot: 42</p>
 				<button>+1</button>
 			</div>
 		`);
diff --git a/test/runtime/samples/component-slot-named-inherits-default-lets/main.svelte b/test/runtime/samples/component-slot-named-inherits-default-lets/main.svelte
index 51dd28b8556c..5e7d3def541d 100644
--- a/test/runtime/samples/component-slot-named-inherits-default-lets/main.svelte
+++ b/test/runtime/samples/component-slot-named-inherits-default-lets/main.svelte
@@ -1,5 +1,6 @@
 <script>
 	import Nested from './Nested.svelte';
+	let count = 42;
 </script>
 
 <Nested let:count>
diff --git a/test/validator/samples/lets-on-component/input.svelte b/test/validator/samples/lets-on-component/input.svelte
new file mode 100644
index 000000000000..b72ee8c07440
--- /dev/null
+++ b/test/validator/samples/lets-on-component/input.svelte
@@ -0,0 +1,27 @@
+<script>
+	import Nested from './Nested.svelte';
+</script>
+
+<Nested let:count>
+	<p>
+		count in default slot: {count}
+	</p>
+	<p slot="bar">
+		count in bar slot: {count}
+	</p>
+</Nested>
+
+<Nested let:count>
+	<p>
+		count in default slot: {count}
+	</p>
+	<p>
+		count in bar slot: {count}
+	</p>
+</Nested>
+
+<Nested let:count>
+	<p slot="bar">
+		count in bar slot: {count}
+	</p>
+</Nested>
diff --git a/test/validator/samples/lets-on-component/warnings.json b/test/validator/samples/lets-on-component/warnings.json
new file mode 100644
index 000000000000..54debf49c69f
--- /dev/null
+++ b/test/validator/samples/lets-on-component/warnings.json
@@ -0,0 +1,62 @@
+[
+	{
+		"code": "let-on-component",
+		"message": "let: bindings on Component are meant for default slot template only, it is better to define them on <svelte:fragment slot=\"default\"> instead.",
+		"pos": 59,
+		"start": {
+			"character": 59,
+			"column": 0,
+			"line": 5
+		},
+		"end": {
+			"character": 182,
+			"column": 9,
+			"line": 12
+		}
+	},
+	{
+		"code": "missing-declaration",
+		"message": "'count' is not defined",
+		"pos": 160,
+		"start": {
+			"character": 160,
+			"column": 22,
+			"line": 10
+		},
+		"end": {
+			"character": 165,
+			"column": 27,
+			"line": 10
+		}
+	},
+	{
+		"code": "let-on-component",
+		"message": "let: bindings on Component are meant for default slot template only, it is better to define them on <svelte:fragment slot=\"default\"> instead.",
+		"pos": 298,
+		"start": {
+			"character": 298,
+			"column": 0,
+			"line": 23
+		},
+		"end": {
+			"character": 377,
+			"column": 9,
+			"line": 27
+		}
+	},
+	{
+		"code": "missing-declaration",
+		"message": "'count' is not defined",
+		"pos": 355,
+		"start": {
+			"character": 355,
+			"column": 22,
+			"line": 25
+		},
+		"end": {
+			"character": 360,
+			"column": 27,
+			"line": 25
+		}
+	}
+]

From bc115a8731238fa5fb0bfca4365016252fa0fad6 Mon Sep 17 00:00:00 2001
From: Tan Li Hau <lhtan93@gmail.com>
Date: Thu, 4 Mar 2021 10:43:33 +0800
Subject: [PATCH 03/18] fix tests

---
 src/compiler/compile/render_ssr/handlers/Slot.ts            | 6 ------
 .../samples/component-slot-nested-in-slot/One.svelte        | 6 ++++--
 .../component-svelte-fragment-let-aliased/main.svelte       | 4 ++--
 .../samples/component-svelte-fragment-let-b/main.svelte     | 4 ++--
 .../samples/component-svelte-fragment-let-e/A.svelte        | 4 ++--
 .../samples/component-svelte-fragment-let-e/_config.js      | 4 ----
 .../samples/component-svelte-fragment-let-e/main.svelte     | 6 ------
 7 files changed, 10 insertions(+), 24 deletions(-)

diff --git a/src/compiler/compile/render_ssr/handlers/Slot.ts b/src/compiler/compile/render_ssr/handlers/Slot.ts
index f89b619c466d..781e62bb0024 100644
--- a/src/compiler/compile/render_ssr/handlers/Slot.ts
+++ b/src/compiler/compile/render_ssr/handlers/Slot.ts
@@ -26,12 +26,6 @@ export default function(node: Slot, renderer: Renderer, options: RenderOptions &
 	`);
 
 	if (slot && nearest_inline_component) {
-		const lets = node.lets;
-		const seen = new Set(lets.map(l => l.name.name));
-
-		nearest_inline_component.lets.forEach(l => {
-			if (!seen.has(l.name.name)) lets.push(l);
-		});
 		options.slot_scopes.set(slot, {
 			input: get_slot_scope(node.lets),
 			output: renderer.pop()
diff --git a/test/runtime/samples/component-slot-nested-in-slot/One.svelte b/test/runtime/samples/component-slot-nested-in-slot/One.svelte
index e27437c450fc..acb6a03358be 100644
--- a/test/runtime/samples/component-slot-nested-in-slot/One.svelte
+++ b/test/runtime/samples/component-slot-nested-in-slot/One.svelte
@@ -3,6 +3,8 @@
 	export let a, b;
 </script>
 
-<Two {b} let:two>
-	<slot name="one" slot="two" one={a} two={two}></slot>
+<Two {b}>
+	<svelte:fragment slot="two" let:two>
+		<slot name="one" one={a} two={two}></slot>
+	</svelte:fragment>
 </Two>
diff --git a/test/runtime/samples/component-svelte-fragment-let-aliased/main.svelte b/test/runtime/samples/component-svelte-fragment-let-aliased/main.svelte
index dabf1d65ef0c..5ca0cbbd100c 100644
--- a/test/runtime/samples/component-svelte-fragment-let-aliased/main.svelte
+++ b/test/runtime/samples/component-svelte-fragment-let-aliased/main.svelte
@@ -4,8 +4,8 @@
 	export let things;
 </script>
 
-<Nested {things} let:thing={x}>
-	<svelte:fragment slot="main">
+<Nested {things}>
+	<svelte:fragment slot="main" let:thing={x}>
 		<span>{x}</span>
 	</svelte:fragment>
 </Nested>
\ No newline at end of file
diff --git a/test/runtime/samples/component-svelte-fragment-let-b/main.svelte b/test/runtime/samples/component-svelte-fragment-let-b/main.svelte
index 584240d14d27..bb24b97a3b15 100644
--- a/test/runtime/samples/component-svelte-fragment-let-b/main.svelte
+++ b/test/runtime/samples/component-svelte-fragment-let-b/main.svelte
@@ -2,8 +2,8 @@
 	import Nested from './Nested.svelte';
 </script>
 
-<Nested let:count>
-	<svelte:fragment slot="main">
+<Nested>
+	<svelte:fragment slot="main" let:count>
 		<span>{count}</span>
 	</svelte:fragment>
 </Nested>
\ No newline at end of file
diff --git a/test/runtime/samples/component-svelte-fragment-let-e/A.svelte b/test/runtime/samples/component-svelte-fragment-let-e/A.svelte
index 3ba0e62cd961..f982aef7b14b 100644
--- a/test/runtime/samples/component-svelte-fragment-let-e/A.svelte
+++ b/test/runtime/samples/component-svelte-fragment-let-e/A.svelte
@@ -3,8 +3,8 @@
 	export let x;
 </script>
 
-<B {x} let:reflected>
-	<svelte:fragment slot="main">
+<B {x}>
+	<svelte:fragment slot="main" let:reflected>
 		<span>{reflected}</span>
 		<slot name="main" {reflected} />
 	</svelte:fragment>
diff --git a/test/runtime/samples/component-svelte-fragment-let-e/_config.js b/test/runtime/samples/component-svelte-fragment-let-e/_config.js
index 967955dfd856..74de38be02cc 100644
--- a/test/runtime/samples/component-svelte-fragment-let-e/_config.js
+++ b/test/runtime/samples/component-svelte-fragment-let-e/_config.js
@@ -2,8 +2,6 @@ export default {
 	html: `
 		<span>1</span>
 		<span>1</span>
-		<span>1</span>
-		<span>1</span>
 	`,
 
 	async test({ assert, target, component }) {
@@ -12,8 +10,6 @@ export default {
 		assert.htmlEqual(target.innerHTML, `
 			<span>2</span>
 			<span>2</span>
-			<span>2</span>
-			<span>2</span>
 		`);
 	}
 };
diff --git a/test/runtime/samples/component-svelte-fragment-let-e/main.svelte b/test/runtime/samples/component-svelte-fragment-let-e/main.svelte
index 80c9a868cd44..e95c8d927414 100644
--- a/test/runtime/samples/component-svelte-fragment-let-e/main.svelte
+++ b/test/runtime/samples/component-svelte-fragment-let-e/main.svelte
@@ -8,9 +8,3 @@
 		<span>{reflected}</span>
 	</svelte:fragment>	
 </A>
-
-<A {x} let:reflected>
-	<svelte:fragment slot="main">
-		<span>{reflected}</span>
-	</svelte:fragment>	
-</A>
\ No newline at end of file

From a4fbc314cf615dacb13c5c51ac25617931b79687 Mon Sep 17 00:00:00 2001
From: Tan Li Hau <lhtan93@gmail.com>
Date: Thu, 4 Mar 2021 13:26:11 +0800
Subject: [PATCH 04/18] fix test

---
 src/compiler/compile/nodes/shared/Expression.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/compiler/compile/nodes/shared/Expression.ts b/src/compiler/compile/nodes/shared/Expression.ts
index 0603c15589d2..d35a3cbb5cbd 100644
--- a/src/compiler/compile/nodes/shared/Expression.ts
+++ b/src/compiler/compile/nodes/shared/Expression.ts
@@ -323,8 +323,8 @@ export default class Expression {
 
 							const func_expression = func_declaration[0];
 
-							if (node.type === 'InlineComponent' || node.type === 'SlotTemplate') {
-								// <Comp let:data />
+							if (node.type === 'SlotTemplate') {
+								// <svelte:fragment let:data />
 								this.replace(func_expression);
 							} else {
 								// {#each}, {#await}

From bd1bd4f42fc4453882413d95c64bddc604b3b4e5 Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Wed, 24 May 2023 13:30:05 +0545
Subject: [PATCH 05/18] fix

---
 src/compiler/compile/nodes/InlineComponent.js        |  1 -
 .../samples/lets-on-component/warnings.json          | 12 ------------
 2 files changed, 13 deletions(-)

diff --git a/src/compiler/compile/nodes/InlineComponent.js b/src/compiler/compile/nodes/InlineComponent.js
index 53ba44408233..7eed473f37b9 100644
--- a/src/compiler/compile/nodes/InlineComponent.js
+++ b/src/compiler/compile/nodes/InlineComponent.js
@@ -81,7 +81,6 @@ export default class InlineComponent extends Node {
 						break;
 					case 'Let':
 						let_attributes.push(node);
-						this.lets.push(new Let(component, this, scope, node));
 						break;
 					case 'Transition':
 						return component.error(node, compiler_errors.invalid_transition);
diff --git a/test/validator/samples/lets-on-component/warnings.json b/test/validator/samples/lets-on-component/warnings.json
index 54debf49c69f..6243a8491b0f 100644
--- a/test/validator/samples/lets-on-component/warnings.json
+++ b/test/validator/samples/lets-on-component/warnings.json
@@ -2,14 +2,11 @@
 	{
 		"code": "let-on-component",
 		"message": "let: bindings on Component are meant for default slot template only, it is better to define them on <svelte:fragment slot=\"default\"> instead.",
-		"pos": 59,
 		"start": {
-			"character": 59,
 			"column": 0,
 			"line": 5
 		},
 		"end": {
-			"character": 182,
 			"column": 9,
 			"line": 12
 		}
@@ -17,14 +14,11 @@
 	{
 		"code": "missing-declaration",
 		"message": "'count' is not defined",
-		"pos": 160,
 		"start": {
-			"character": 160,
 			"column": 22,
 			"line": 10
 		},
 		"end": {
-			"character": 165,
 			"column": 27,
 			"line": 10
 		}
@@ -32,14 +26,11 @@
 	{
 		"code": "let-on-component",
 		"message": "let: bindings on Component are meant for default slot template only, it is better to define them on <svelte:fragment slot=\"default\"> instead.",
-		"pos": 298,
 		"start": {
-			"character": 298,
 			"column": 0,
 			"line": 23
 		},
 		"end": {
-			"character": 377,
 			"column": 9,
 			"line": 27
 		}
@@ -47,14 +38,11 @@
 	{
 		"code": "missing-declaration",
 		"message": "'count' is not defined",
-		"pos": 355,
 		"start": {
-			"character": 355,
 			"column": 22,
 			"line": 25
 		},
 		"end": {
-			"character": 360,
 			"column": 27,
 			"line": 25
 		}

From 6111352451967a7a44d6a5525e734ab16dc59aab Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Wed, 24 May 2023 13:53:41 +0545
Subject: [PATCH 06/18] add runtime tests

---
 .../samples/component-slot-let-scope-2/Nested.svelte      | 3 +++
 .../runtime/samples/component-slot-let-scope-2/_config.js | 3 +++
 .../samples/component-slot-let-scope-2/main.svelte        | 8 ++++++++
 .../samples/component-slot-let-scope/Nested.svelte        | 2 ++
 test/runtime/samples/component-slot-let-scope/_config.js  | 3 +++
 test/runtime/samples/component-slot-let-scope/main.svelte | 8 ++++++++
 6 files changed, 27 insertions(+)
 create mode 100644 test/runtime/samples/component-slot-let-scope-2/Nested.svelte
 create mode 100644 test/runtime/samples/component-slot-let-scope-2/_config.js
 create mode 100644 test/runtime/samples/component-slot-let-scope-2/main.svelte
 create mode 100644 test/runtime/samples/component-slot-let-scope/Nested.svelte
 create mode 100644 test/runtime/samples/component-slot-let-scope/_config.js
 create mode 100644 test/runtime/samples/component-slot-let-scope/main.svelte

diff --git a/test/runtime/samples/component-slot-let-scope-2/Nested.svelte b/test/runtime/samples/component-slot-let-scope-2/Nested.svelte
new file mode 100644
index 000000000000..e231bf1a7feb
--- /dev/null
+++ b/test/runtime/samples/component-slot-let-scope-2/Nested.svelte
@@ -0,0 +1,3 @@
+<slot />
+<slot thing={2} name="thing"/>
+	
\ No newline at end of file
diff --git a/test/runtime/samples/component-slot-let-scope-2/_config.js b/test/runtime/samples/component-slot-let-scope-2/_config.js
new file mode 100644
index 000000000000..b4a181dc6766
--- /dev/null
+++ b/test/runtime/samples/component-slot-let-scope-2/_config.js
@@ -0,0 +1,3 @@
+export default {
+	html: `<span>undefined</span><span>2</span>`
+};
diff --git a/test/runtime/samples/component-slot-let-scope-2/main.svelte b/test/runtime/samples/component-slot-let-scope-2/main.svelte
new file mode 100644
index 000000000000..8454c4acd178
--- /dev/null
+++ b/test/runtime/samples/component-slot-let-scope-2/main.svelte
@@ -0,0 +1,8 @@
+<script>
+	import Nested from './Nested.svelte';
+</script>
+
+<Nested let:thing>
+	<span>{thing}</span>
+	<svelte:fragment slot="thing" let:thing><span>{thing}</span></svelte:fragment>
+</Nested>
\ No newline at end of file
diff --git a/test/runtime/samples/component-slot-let-scope/Nested.svelte b/test/runtime/samples/component-slot-let-scope/Nested.svelte
new file mode 100644
index 000000000000..772955e06efa
--- /dev/null
+++ b/test/runtime/samples/component-slot-let-scope/Nested.svelte
@@ -0,0 +1,2 @@
+<slot thing={2} name="thing"/>
+	
\ No newline at end of file
diff --git a/test/runtime/samples/component-slot-let-scope/_config.js b/test/runtime/samples/component-slot-let-scope/_config.js
new file mode 100644
index 000000000000..d8fbab2bae68
--- /dev/null
+++ b/test/runtime/samples/component-slot-let-scope/_config.js
@@ -0,0 +1,3 @@
+export default {
+	error: `thing is not defined`
+};
diff --git a/test/runtime/samples/component-slot-let-scope/main.svelte b/test/runtime/samples/component-slot-let-scope/main.svelte
new file mode 100644
index 000000000000..e10a9a858491
--- /dev/null
+++ b/test/runtime/samples/component-slot-let-scope/main.svelte
@@ -0,0 +1,8 @@
+<script>
+	import Nested from './Nested.svelte';
+
+</script>
+
+<Nested let:thing>
+	<svelte:fragment slot="thing"><span>{thing}</span></svelte:fragment>
+</Nested>
\ No newline at end of file

From c4bf84a421e9562016fa4379599700d9010d8e05 Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Fri, 26 May 2023 09:43:57 +0545
Subject: [PATCH 07/18] rename test since it doesn't inherit anymore

---
 .../Nested.svelte                                                 | 0
 .../_config.js                                                    | 0
 .../main.svelte                                                   | 0
 3 files changed, 0 insertions(+), 0 deletions(-)
 rename test/runtime/samples/{component-slot-named-inherits-default-lets => component-slot-let-scope-3}/Nested.svelte (100%)
 rename test/runtime/samples/{component-slot-named-inherits-default-lets => component-slot-let-scope-3}/_config.js (100%)
 rename test/runtime/samples/{component-slot-named-inherits-default-lets => component-slot-let-scope-3}/main.svelte (100%)

diff --git a/test/runtime/samples/component-slot-named-inherits-default-lets/Nested.svelte b/test/runtime/samples/component-slot-let-scope-3/Nested.svelte
similarity index 100%
rename from test/runtime/samples/component-slot-named-inherits-default-lets/Nested.svelte
rename to test/runtime/samples/component-slot-let-scope-3/Nested.svelte
diff --git a/test/runtime/samples/component-slot-named-inherits-default-lets/_config.js b/test/runtime/samples/component-slot-let-scope-3/_config.js
similarity index 100%
rename from test/runtime/samples/component-slot-named-inherits-default-lets/_config.js
rename to test/runtime/samples/component-slot-let-scope-3/_config.js
diff --git a/test/runtime/samples/component-slot-named-inherits-default-lets/main.svelte b/test/runtime/samples/component-slot-let-scope-3/main.svelte
similarity index 100%
rename from test/runtime/samples/component-slot-named-inherits-default-lets/main.svelte
rename to test/runtime/samples/component-slot-let-scope-3/main.svelte

From 3ed219ea1acfe98c7e1676ea448b237a3055915f Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Fri, 26 May 2023 16:52:47 +0545
Subject: [PATCH 08/18] fix lint

---
 test/runtime/samples/component-slot-let-scope-2/_config.js     | 2 +-
 test/runtime/samples/component-slot-let-scope/_config.js       | 2 +-
 .../runtime/samples/component-svelte-fragment-let-e/_config.js | 3 ++-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/test/runtime/samples/component-slot-let-scope-2/_config.js b/test/runtime/samples/component-slot-let-scope-2/_config.js
index b4a181dc6766..6b2059f03d0b 100644
--- a/test/runtime/samples/component-slot-let-scope-2/_config.js
+++ b/test/runtime/samples/component-slot-let-scope-2/_config.js
@@ -1,3 +1,3 @@
 export default {
-	html: `<span>undefined</span><span>2</span>`
+	html: '<span>undefined</span><span>2</span>'
 };
diff --git a/test/runtime/samples/component-slot-let-scope/_config.js b/test/runtime/samples/component-slot-let-scope/_config.js
index d8fbab2bae68..c0f4d293055e 100644
--- a/test/runtime/samples/component-slot-let-scope/_config.js
+++ b/test/runtime/samples/component-slot-let-scope/_config.js
@@ -1,3 +1,3 @@
 export default {
-	error: `thing is not defined`
+	error: 'thing is not defined'
 };
diff --git a/test/runtime/samples/component-svelte-fragment-let-e/_config.js b/test/runtime/samples/component-svelte-fragment-let-e/_config.js
index 403a198db3eb..1ececbb3efe8 100644
--- a/test/runtime/samples/component-svelte-fragment-let-e/_config.js
+++ b/test/runtime/samples/component-svelte-fragment-let-e/_config.js
@@ -12,6 +12,7 @@ export default {
 			`
 			<span>2</span>
 			<span>2</span>
-		`);
+		`
+		);
 	}
 };

From a983324a17d83fa7e3a4d82205c6ecb19ba70b86 Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Fri, 26 May 2023 17:24:09 +0545
Subject: [PATCH 09/18] remove warnings

---
 src/compiler/compile/nodes/InlineComponent.js |  8 -------
 .../samples/lets-on-component/warnings.json   | 24 -------------------
 2 files changed, 32 deletions(-)

diff --git a/src/compiler/compile/nodes/InlineComponent.js b/src/compiler/compile/nodes/InlineComponent.js
index 7eed473f37b9..e41ec37af1f7 100644
--- a/src/compiler/compile/nodes/InlineComponent.js
+++ b/src/compiler/compile/nodes/InlineComponent.js
@@ -162,20 +162,12 @@ export default class InlineComponent extends Node {
 		}
 
 		if (let_attributes.length) {
-			let warned = false;
 			// copy let: attribute from <Component /> to <svelte:fragment slot="default" />
 			// as they are for `slot="default"` only
 			children.forEach((child) => {
 				const slot = child.attributes.find((attribute) => attribute.name === 'slot');
 				if (!slot || slot.value[0].data === 'default') {
 					child.attributes.push(...let_attributes);
-				} else if (!warned) {
-					component.warn(info, {
-						code: 'let-on-component',
-						message:
-							'let: bindings on Component are meant for default slot template only, it is better to define them on <svelte:fragment slot="default"> instead.'
-					});
-					warned = true;
 				}
 			});
 		}
diff --git a/test/validator/samples/lets-on-component/warnings.json b/test/validator/samples/lets-on-component/warnings.json
index 6243a8491b0f..dc5bb7da002f 100644
--- a/test/validator/samples/lets-on-component/warnings.json
+++ b/test/validator/samples/lets-on-component/warnings.json
@@ -1,16 +1,4 @@
 [
-	{
-		"code": "let-on-component",
-		"message": "let: bindings on Component are meant for default slot template only, it is better to define them on <svelte:fragment slot=\"default\"> instead.",
-		"start": {
-			"column": 0,
-			"line": 5
-		},
-		"end": {
-			"column": 9,
-			"line": 12
-		}
-	},
 	{
 		"code": "missing-declaration",
 		"message": "'count' is not defined",
@@ -23,18 +11,6 @@
 			"line": 10
 		}
 	},
-	{
-		"code": "let-on-component",
-		"message": "let: bindings on Component are meant for default slot template only, it is better to define them on <svelte:fragment slot=\"default\"> instead.",
-		"start": {
-			"column": 0,
-			"line": 23
-		},
-		"end": {
-			"column": 9,
-			"line": 27
-		}
-	},
 	{
 		"code": "missing-declaration",
 		"message": "'count' is not defined",

From f7b1ff8ec92c9851dd44fb16e39f11d50e3cb616 Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Fri, 26 May 2023 17:26:42 +0545
Subject: [PATCH 10/18] add compile script

---
 scripts/compile-test.js | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 scripts/compile-test.js

diff --git a/scripts/compile-test.js b/scripts/compile-test.js
new file mode 100644
index 000000000000..bbc0379433c7
--- /dev/null
+++ b/scripts/compile-test.js
@@ -0,0 +1,28 @@
+import { mkdirSync, readFileSync, writeFileSync } from 'fs';
+import path from 'path';
+import glob from 'tiny-glob/sync.js';
+import { compile } from '../src/compiler/index.js';
+
+const cwd = path.resolve(process.argv[2]);
+
+const options = [
+	['normal', {}],
+	['hydrate', { hydratable: true }],
+	['ssr', { generate: 'ssr' }]
+];
+for (const file of glob('**/*.svelte', { cwd })) {
+	const contents = readFileSync(`${cwd}/${file}`, 'utf-8').replace(/\r/g, '');
+
+	for (const [name, opts] of options) {
+		const dir = `${cwd}/_output/${name}`;
+
+		const { js, css } = compile(contents, {
+			...opts,
+			filename: file
+		});
+
+		mkdirSync(dir, { recursive: true });
+		js.code && writeFileSync(`${dir}/${file.replace(/\.svelte$/, '.js')}`, js.code);
+		css.code && writeFileSync(`${dir}/${file.replace(/\.svelte$/, '.css')}`, css.code);
+	}
+}

From 36f98aca655fa3249c1b1d66eeb51bc886621ce2 Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Fri, 26 May 2023 19:22:24 +0545
Subject: [PATCH 11/18] document script

---
 scripts/compile-test.js | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/scripts/compile-test.js b/scripts/compile-test.js
index bbc0379433c7..d2be2183ed49 100644
--- a/scripts/compile-test.js
+++ b/scripts/compile-test.js
@@ -1,3 +1,6 @@
+// Compile all Svelte files in a directory to JS and CSS files
+// Usage: node scripts/compile-test.js <directory>
+
 import { mkdirSync, readFileSync, writeFileSync } from 'fs';
 import path from 'path';
 import glob from 'tiny-glob/sync.js';
@@ -12,17 +15,26 @@ const options = [
 ];
 for (const file of glob('**/*.svelte', { cwd })) {
 	const contents = readFileSync(`${cwd}/${file}`, 'utf-8').replace(/\r/g, '');
-
+	let w;
 	for (const [name, opts] of options) {
 		const dir = `${cwd}/_output/${name}`;
 
-		const { js, css } = compile(contents, {
+		const { js, css, warnings } = compile(contents, {
 			...opts,
 			filename: file
 		});
 
+		if (warnings.length) {
+            w = warnings;
+        }
+
 		mkdirSync(dir, { recursive: true });
 		js.code && writeFileSync(`${dir}/${file.replace(/\.svelte$/, '.js')}`, js.code);
 		css.code && writeFileSync(`${dir}/${file.replace(/\.svelte$/, '.css')}`, css.code);
 	}
+
+	if (w) {
+		console.log(`Warnings for ${file}:`);
+		console.log(w);
+	}
 }

From b27dd26cab1e2351e15e8ace2c329bdb52dd11bd Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Fri, 26 May 2023 19:31:18 +0545
Subject: [PATCH 12/18] improve warning

---
 src/compiler/compile/Component.js               | 11 ++++++++++-
 src/compiler/compile/nodes/InlineComponent.js   |  4 +++-
 src/compiler/compile/nodes/shared/Expression.js |  4 +++-
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/compiler/compile/Component.js b/src/compiler/compile/Component.js
index 5a4b063651d8..1778f89d27e2 100644
--- a/src/compiler/compile/Component.js
+++ b/src/compiler/compile/Component.js
@@ -1644,8 +1644,9 @@ export default class Component {
 	 * @param {string} name
 	 * @param {any} node
 	 * @param {import('./nodes/shared/TemplateScope.js').default} template_scope
+	 * @param {import("./nodes/shared/Node.js").default} [owner]
 	 */
-	warn_if_undefined(name, node, template_scope) {
+	warn_if_undefined(name, node, template_scope, owner) {
 		if (name[0] === '$') {
 			if (name === '$' || (name[1] === '$' && !is_reserved_keyword(name))) {
 				return this.error(node, compiler_errors.illegal_global(name));
@@ -1657,6 +1658,14 @@ export default class Component {
 		if (this.var_lookup.has(name) && !this.var_lookup.get(name).global) return;
 		if (template_scope && template_scope.names.has(name)) return;
 		if (globals.has(name) && node.type !== 'InlineComponent') return;
+
+		if (owner?.find_nearest(/InlineComponent/)?.let_attributes.find((attr) => attr.name === name)) {
+			return this.warn(node, {
+				code: 'missing-declaration',
+				message: `let:${name} declared on parent component cannot be used inside named slot`
+			});
+		}
+
 		this.warn(node, compiler_warnings.missing_declaration(name, !!this.ast.instance));
 	}
 
diff --git a/src/compiler/compile/nodes/InlineComponent.js b/src/compiler/compile/nodes/InlineComponent.js
index e41ec37af1f7..f863f265fe44 100644
--- a/src/compiler/compile/nodes/InlineComponent.js
+++ b/src/compiler/compile/nodes/InlineComponent.js
@@ -33,6 +33,8 @@ export default class InlineComponent extends Node {
 	/** @type {string} */
 	namespace;
 
+	/** @type {Node[]} */
+	let_attributes;
 	/**
 	 * @param {import('../Component.js').default} component
 	 * @param {import('./shared/Node.js').default} parent
@@ -55,7 +57,7 @@ export default class InlineComponent extends Node {
 				? new Expression(component, this, scope, info.expression)
 				: null;
 
-		const let_attributes = [];
+		const let_attributes = this.let_attributes = [];
 		info.attributes.forEach(
 			/** @param {any} node */ (node) => {
 				/* eslint-disable no-fallthrough */
diff --git a/src/compiler/compile/nodes/shared/Expression.js b/src/compiler/compile/nodes/shared/Expression.js
index c9621ab6c45b..c4877f7c84ee 100644
--- a/src/compiler/compile/nodes/shared/Expression.js
+++ b/src/compiler/compile/nodes/shared/Expression.js
@@ -77,6 +77,7 @@ export default class Expression {
 		this.scope_map = map;
 		const expression = this;
 		let function_expression;
+
 		// discover dependencies, but don't change the code yet
 		walk(info, {
 			/**
@@ -125,7 +126,7 @@ export default class Expression {
 							dependencies.add(name);
 						}
 						component.add_reference(node, name);
-						component.warn_if_undefined(name, nodes[0], template_scope);
+						component.warn_if_undefined(name, nodes[0], template_scope, owner);
 					}
 					this.skip();
 				}
@@ -459,6 +460,7 @@ export default class Expression {
 				}
 			}
 		});
+
 		if (declarations.length > 0) {
 			block.maintain_context = true;
 			declarations.forEach(

From c6e3e6d739cf973db22ff8e634e155ac62fd24de Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Fri, 26 May 2023 19:32:08 +0545
Subject: [PATCH 13/18] fix test

---
 test/validator/samples/lets-on-component/warnings.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/validator/samples/lets-on-component/warnings.json b/test/validator/samples/lets-on-component/warnings.json
index dc5bb7da002f..9fb7827b47ea 100644
--- a/test/validator/samples/lets-on-component/warnings.json
+++ b/test/validator/samples/lets-on-component/warnings.json
@@ -1,7 +1,7 @@
 [
 	{
 		"code": "missing-declaration",
-		"message": "'count' is not defined",
+		"message": "let:count declared on parent component cannot be used inside named slot",
 		"start": {
 			"column": 22,
 			"line": 10
@@ -13,7 +13,7 @@
 	},
 	{
 		"code": "missing-declaration",
-		"message": "'count' is not defined",
+		"message": "let:count declared on parent component cannot be used inside named slot",
 		"start": {
 			"column": 22,
 			"line": 25

From 86802101ff420ef8ace7dc88135b1ab0bb008ffa Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Fri, 26 May 2023 19:45:59 +0545
Subject: [PATCH 14/18] handle renames

---
 src/compiler/compile/Component.js                     | 9 ++++++++-
 test/validator/samples/lets-on-component/input.svelte | 2 +-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/compiler/compile/Component.js b/src/compiler/compile/Component.js
index 1778f89d27e2..fc98a323b848 100644
--- a/src/compiler/compile/Component.js
+++ b/src/compiler/compile/Component.js
@@ -1659,7 +1659,14 @@ export default class Component {
 		if (template_scope && template_scope.names.has(name)) return;
 		if (globals.has(name) && node.type !== 'InlineComponent') return;
 
-		if (owner?.find_nearest(/InlineComponent/)?.let_attributes.find((attr) => attr.name === name)) {
+		if (
+			owner?.find_nearest(/InlineComponent/)?.let_attributes.find((attr) => {
+				// TODO: let:foo={{ bar }} doesn't work properly cause it's returned as an
+				// ObjectExpression instead of a Pattern
+				const names = attr.expression ? extract_names(attr.expression) : [attr.name];
+				return names.includes(name);
+			})
+		) {
 			return this.warn(node, {
 				code: 'missing-declaration',
 				message: `let:${name} declared on parent component cannot be used inside named slot`
diff --git a/test/validator/samples/lets-on-component/input.svelte b/test/validator/samples/lets-on-component/input.svelte
index b72ee8c07440..8ad7424245e0 100644
--- a/test/validator/samples/lets-on-component/input.svelte
+++ b/test/validator/samples/lets-on-component/input.svelte
@@ -20,7 +20,7 @@
 	</p>
 </Nested>
 
-<Nested let:count>
+<Nested let:foo={count}>
 	<p slot="bar">
 		count in bar slot: {count}
 	</p>

From 46cdb12534f4cf26e1e08b97a75e9f0cf14c6825 Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Fri, 26 May 2023 19:49:12 +0545
Subject: [PATCH 15/18] fix lint

---
 scripts/compile-test.js                       | 4 ++--
 src/compiler/compile/nodes/InlineComponent.js | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/scripts/compile-test.js b/scripts/compile-test.js
index d2be2183ed49..9a83708b3833 100644
--- a/scripts/compile-test.js
+++ b/scripts/compile-test.js
@@ -25,8 +25,8 @@ for (const file of glob('**/*.svelte', { cwd })) {
 		});
 
 		if (warnings.length) {
-            w = warnings;
-        }
+			w = warnings;
+		}
 
 		mkdirSync(dir, { recursive: true });
 		js.code && writeFileSync(`${dir}/${file.replace(/\.svelte$/, '.js')}`, js.code);
diff --git a/src/compiler/compile/nodes/InlineComponent.js b/src/compiler/compile/nodes/InlineComponent.js
index f863f265fe44..9aafe3965ca6 100644
--- a/src/compiler/compile/nodes/InlineComponent.js
+++ b/src/compiler/compile/nodes/InlineComponent.js
@@ -57,7 +57,7 @@ export default class InlineComponent extends Node {
 				? new Expression(component, this, scope, info.expression)
 				: null;
 
-		const let_attributes = this.let_attributes = [];
+		const let_attributes = (this.let_attributes = []);
 		info.attributes.forEach(
 			/** @param {any} node */ (node) => {
 				/* eslint-disable no-fallthrough */

From 7fa1615142b9b81028bf56e94cb777fd9bc9370f Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Fri, 26 May 2023 21:31:51 +0545
Subject: [PATCH 16/18] gather names from all parents instead of just the
 nearest

---
 src/compiler/compile/Component.js             | 29 ++++++++++++++-----
 src/compiler/compile/nodes/InlineComponent.js |  2 +-
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/src/compiler/compile/Component.js b/src/compiler/compile/Component.js
index fc98a323b848..161633d1e918 100644
--- a/src/compiler/compile/Component.js
+++ b/src/compiler/compile/Component.js
@@ -28,6 +28,7 @@ import {
 	extract_svelte_ignore_from_comments
 } from '../utils/extract_svelte_ignore.js';
 import check_enable_sourcemap from './utils/check_enable_sourcemap.js';
+import Attribute from './nodes/Attribute.js';
 
 const regex_leading_directory_separator = /^[/\\]/;
 const regex_starts_with_term_export = /^Export/;
@@ -1659,14 +1660,26 @@ export default class Component {
 		if (template_scope && template_scope.names.has(name)) return;
 		if (globals.has(name) && node.type !== 'InlineComponent') return;
 
-		if (
-			owner?.find_nearest(/InlineComponent/)?.let_attributes.find((attr) => {
-				// TODO: let:foo={{ bar }} doesn't work properly cause it's returned as an
-				// ObjectExpression instead of a Pattern
-				const names = attr.expression ? extract_names(attr.expression) : [attr.name];
-				return names.includes(name);
-			})
-		) {
+		function has_out_of_scope_let() {
+			for (let parent = owner.parent; parent; parent = parent.parent) {
+				if (parent.type === 'InlineComponent') {
+					const { let_attributes } = parent;
+
+					for (const attr of let_attributes) {
+						if (
+							// @ts-expect-error
+							(attr.expression && extract_names(attr.expression).includes(name)) ||
+							attr.name === name
+						)
+							return true;
+					}
+				}
+			}
+
+			return false;
+		}
+
+		if (owner && has_out_of_scope_let()) {
 			return this.warn(node, {
 				code: 'missing-declaration',
 				message: `let:${name} declared on parent component cannot be used inside named slot`
diff --git a/src/compiler/compile/nodes/InlineComponent.js b/src/compiler/compile/nodes/InlineComponent.js
index 9aafe3965ca6..d30358f6bde7 100644
--- a/src/compiler/compile/nodes/InlineComponent.js
+++ b/src/compiler/compile/nodes/InlineComponent.js
@@ -33,7 +33,7 @@ export default class InlineComponent extends Node {
 	/** @type {string} */
 	namespace;
 
-	/** @type {Node[]} */
+	/** @type {Attribute[]} */
 	let_attributes;
 	/**
 	 * @param {import('../Component.js').default} component

From 0cb7561470dad4b290b62f235c9c1add5f6e364e Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Fri, 26 May 2023 21:34:16 +0545
Subject: [PATCH 17/18] remove unused import

---
 src/compiler/compile/Component.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/compiler/compile/Component.js b/src/compiler/compile/Component.js
index 161633d1e918..71802d092fab 100644
--- a/src/compiler/compile/Component.js
+++ b/src/compiler/compile/Component.js
@@ -28,7 +28,6 @@ import {
 	extract_svelte_ignore_from_comments
 } from '../utils/extract_svelte_ignore.js';
 import check_enable_sourcemap from './utils/check_enable_sourcemap.js';
-import Attribute from './nodes/Attribute.js';
 
 const regex_leading_directory_separator = /^[/\\]/;
 const regex_starts_with_term_export = /^Export/;

From aa0f75694effd973bf7528d60ee0be9601be72db Mon Sep 17 00:00:00 2001
From: gtmnayan <gtmnayan@gmail.com>
Date: Fri, 26 May 2023 21:52:28 +0545
Subject: [PATCH 18/18] add reminder

---
 src/compiler/compile/Component.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/compiler/compile/Component.js b/src/compiler/compile/Component.js
index 71802d092fab..084063aff315 100644
--- a/src/compiler/compile/Component.js
+++ b/src/compiler/compile/Component.js
@@ -1667,6 +1667,7 @@ export default class Component {
 					for (const attr of let_attributes) {
 						if (
 							// @ts-expect-error
+							// TODO extract_names only considers patterns but let attributes return expressions
 							(attr.expression && extract_names(attr.expression).includes(name)) ||
 							attr.name === name
 						)