From 881e84f988f56026a340588e62a14df3460f9f02 Mon Sep 17 00:00:00 2001
From: Simon H <5968653+dummdidumm@users.noreply.github.com>
Date: Wed, 6 Mar 2024 21:25:08 +0100
Subject: [PATCH] chore: get more validator tests passing (#10714)

Get more validation tests passing:
- const tag cyclic validation (now runtime, based because of new reactivity system)
- illegal-variable-declaration
- illegal-attribute-character
- remove invalid-reactive-var validation as legacy reactive statements are transformed to functions under the hood, which never escape scope - arguably not completely correct, but will be what the user expects anyway
- invalid-rest-eachblock-binding
- remove edge-case redundant-event-modifier warning because event modifiers are deprecated anyway
- invalid-style-directive-modifier
- invalid-tag-property (now a different error)
- module-script-reactive-declaration
- take comment above script into account when silencing warnings
- invalid-css-declaration
- unused-export-let
- invalid-html-attribute
- illegal-store-subscription
- empty-block
---
 packages/svelte/src/compiler/errors.js        |  38 ++----
 .../src/compiler/phases/1-parse/read/style.js |   4 +
 .../compiler/phases/1-parse/state/element.js  |  41 +++++--
 .../src/compiler/phases/2-analyze/index.js    |  44 ++++++-
 .../compiler/phases/2-analyze/validation.js   | 115 +++++++++++++++++-
 .../3-transform/client/visitors/template.js   |  12 ++
 packages/svelte/src/compiler/phases/scope.js  |  45 +++++--
 packages/svelte/src/compiler/types/index.d.ts |   5 +
 .../svelte/src/compiler/types/template.d.ts   |   3 -
 packages/svelte/src/compiler/warnings.js      |  38 +++++-
 .../samples/store-contextual/_config.js       |   6 +-
 .../_config.js                                |   5 +-
 .../samples/store-shadow-scope/_config.js     |   6 +-
 .../_config.js                                |   6 +-
 .../samples/comment-before-script/output.json |   1 +
 .../_config.js                                |   9 ++
 .../main.svelte}                              |   4 +-
 .../samples/const-tag-cyclical/_config.js     |   3 -
 .../samples/const-tag-cyclical/errors.json    |   8 --
 .../validator/samples/empty-block/_config.js  |   3 -
 .../samples/empty-block/input.svelte          |  13 +-
 .../samples/empty-block/warnings.json         |  32 ++---
 .../event-modifiers-redundant/_config.js      |   3 -
 .../event-modifiers-redundant/input.svelte    |  12 --
 .../event-modifiers-redundant/warnings.json   |  26 ----
 .../illegal-attribute-character/_config.js    |   3 -
 .../illegal-variable-declaration/_config.js   |   3 -
 .../illegal-variable-declaration/errors.json  |   8 +-
 .../illegal-variable-declaration/input.svelte |   6 +
 .../invalid-empty-css-declaration/_config.js  |   3 -
 .../invalid-empty-css-declaration/errors.json |  10 +-
 .../samples/invalid-reactive-var-1/_config.js |   3 -
 .../invalid-reactive-var-1/errors.json        |   8 --
 .../invalid-reactive-var-1/input.svelte       |  20 ---
 .../samples/invalid-reactive-var-2/_config.js |   3 -
 .../invalid-reactive-var-2/errors.json        |   8 --
 .../invalid-reactive-var-2/input.svelte       |   8 --
 .../reactive-module-variable/_config.js       |   3 -
 .../reactive-module-variable/warnings.json    |   4 +-
 .../rest-eachblock-binding-2/_config.js       |   4 -
 .../rest-eachblock-binding-3/_config.js       |   4 -
 .../_config.js                                |   4 -
 .../samples/rest-eachblock-binding/_config.js |   4 -
 .../samples/silence-warnings-2/input.svelte   |   3 +-
 .../samples/silence-warnings/input.svelte     |   2 -
 .../_config.js                                |   3 -
 .../errors.json                               |   2 +-
 .../validator/samples/tag-invalid/_config.js  |   3 -
 .../validator/samples/tag-invalid/errors.json |   2 +-
 .../samples/tag-non-string/_config.js         |   3 -
 .../samples/tag-non-string/errors.json        |   6 +-
 .../samples/tag-non-string/input.svelte       |   2 +-
 .../unreferenced-variables-each/_config.js    |   3 -
 .../unreferenced-variables-each/warnings.json |   4 +-
 .../samples/unreferenced-variables/_config.js |   3 -
 .../unreferenced-variables/warnings.json      |  22 ++--
 .../samples/use-the-platform/_config.js       |   3 -
 packages/svelte/types/index.d.ts              |   9 ++
 58 files changed, 374 insertions(+), 284 deletions(-)
 create mode 100644 packages/svelte/tests/runtime-legacy/samples/const-tag-used-before-initialised copy/_config.js
 rename packages/svelte/tests/{validator/samples/const-tag-cyclical/input.svelte => runtime-legacy/samples/const-tag-used-before-initialised copy/main.svelte} (70%)
 delete mode 100644 packages/svelte/tests/validator/samples/const-tag-cyclical/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/const-tag-cyclical/errors.json
 delete mode 100644 packages/svelte/tests/validator/samples/empty-block/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/event-modifiers-redundant/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/event-modifiers-redundant/input.svelte
 delete mode 100644 packages/svelte/tests/validator/samples/event-modifiers-redundant/warnings.json
 delete mode 100644 packages/svelte/tests/validator/samples/illegal-attribute-character/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/illegal-variable-declaration/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/invalid-empty-css-declaration/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/invalid-reactive-var-1/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/invalid-reactive-var-1/errors.json
 delete mode 100644 packages/svelte/tests/validator/samples/invalid-reactive-var-1/input.svelte
 delete mode 100644 packages/svelte/tests/validator/samples/invalid-reactive-var-2/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/invalid-reactive-var-2/errors.json
 delete mode 100644 packages/svelte/tests/validator/samples/invalid-reactive-var-2/input.svelte
 delete mode 100644 packages/svelte/tests/validator/samples/reactive-module-variable/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/rest-eachblock-binding-2/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/rest-eachblock-binding-3/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/rest-eachblock-binding-nested-rest/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/rest-eachblock-binding/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/style-directive-modifiers-invalid/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/tag-invalid/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/tag-non-string/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/unreferenced-variables-each/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/unreferenced-variables/_config.js
 delete mode 100644 packages/svelte/tests/validator/samples/use-the-platform/_config.js

diff --git a/packages/svelte/src/compiler/errors.js b/packages/svelte/src/compiler/errors.js
index c31ad4a038..72397e1f6e 100644
--- a/packages/svelte/src/compiler/errors.js
+++ b/packages/svelte/src/compiler/errors.js
@@ -110,7 +110,8 @@ const css = {
 		`:global(...) must not contain type or universal selectors when used in a compound selector`,
 	'invalid-css-selector': () => `Invalid selector`,
 	'invalid-css-identifier': () => 'Expected a valid CSS identifier',
-	'invalid-nesting-selector': () => `Nesting selectors can only be used inside a rule`
+	'invalid-nesting-selector': () => `Nesting selectors can only be used inside a rule`,
+	'invalid-css-declaration': () => 'Declaration cannot be empty'
 };
 
 /** @satisfies {Errors} */
@@ -278,7 +279,9 @@ const attributes = {
 					directive2
 				)} directive`;
 	},
-	'invalid-let-directive-placement': () => 'let directive at invalid position'
+	'invalid-let-directive-placement': () => 'let directive at invalid position',
+	'invalid-style-directive-modifier': () =>
+		`Invalid 'style:' modifier. Valid modifiers are: 'important'`
 };
 
 /** @satisfies {Errors} */
@@ -330,7 +333,11 @@ const variables = {
 		`${name} is an illegal variable name. To reference a global variable called ${name}, use globalThis.${name}`,
 	/** @param {string} name */
 	'duplicate-declaration': (name) => `'${name}' has already been declared`,
-	'default-export': () => `A component cannot have a default export`
+	'default-export': () => `A component cannot have a default export`,
+	'illegal-variable-declaration': () =>
+		'Cannot declare same variable name which is imported inside <script context="module">',
+	'illegal-store-subscription': () =>
+		'Cannot subscribe to stores that are not declared at the top level of the component'
 };
 
 /** @satisfies {Errors} */
@@ -435,11 +442,6 @@ const errors = {
 	// 		message
 	// 	};
 	// },
-	// contextual_store: {
-	// 	code: 'contextual-store',
-	// 	message:
-	// 		'Stores must be declared at the top level of the component (this may change in a future version of Svelte)'
-	// },
 	// default_export: {
 	// 	code: 'default-export',
 	// 	message: 'A component cannot have a default export'
@@ -448,31 +450,11 @@ const errors = {
 	// 	code: 'illegal-declaration',
 	// 	message: 'The $ prefix is reserved, and cannot be used for variable and import names'
 	// },
-	// illegal_global: /** @param {string} name */ (name) => ({
-	// 	code: 'illegal-global',
-	// 	message: `${name} is an illegal variable name`
-	// }),
-	// illegal_variable_declaration: {
-	// 	code: 'illegal-variable-declaration',
-	// 	message: 'Cannot declare same variable name which is imported inside <script context="module">'
-	// },
 	// invalid_directive_value: {
 	// 	code: 'invalid-directive-value',
 	// 	message:
 	// 		'Can only bind to an identifier (e.g. `foo`) or a member expression (e.g. `foo.bar` or `foo[baz]`)'
 	// },
-	// cyclical_const_tags: /** @param {string[]} cycle */ (cycle) => ({
-	// 	code: 'cyclical-const-tags',
-	// 	message: `Cyclical dependency detected: ${cycle.join(' → ')}`
-	// }),
-	// invalid_var_declaration: {
-	// 	code: 'invalid_var_declaration',
-	// 	message: '"var" scope should not extend outside the reactive block'
-	// },
-	// invalid_style_directive_modifier: /** @param {string} valid */ (valid) => ({
-	// 	code: 'invalid-style-directive-modifier',
-	// 	message: `Valid modifiers for style directives are: ${valid}`
-	// })
 };
 
 // interface is duplicated between here (used internally) and ./interfaces.js
diff --git a/packages/svelte/src/compiler/phases/1-parse/read/style.js b/packages/svelte/src/compiler/phases/1-parse/read/style.js
index 5cde3bc3c6..ee5c8395f8 100644
--- a/packages/svelte/src/compiler/phases/1-parse/read/style.js
+++ b/packages/svelte/src/compiler/phases/1-parse/read/style.js
@@ -476,6 +476,10 @@ function read_declaration(parser) {
 
 	const value = read_value(parser);
 
+	if (!value && !property.startsWith('--')) {
+		error(parser.index, 'invalid-css-declaration');
+	}
+
 	const end = parser.index;
 
 	if (!parser.match('}')) {
diff --git a/packages/svelte/src/compiler/phases/1-parse/state/element.js b/packages/svelte/src/compiler/phases/1-parse/state/element.js
index d2c9e4ee29..f40bccd444 100644
--- a/packages/svelte/src/compiler/phases/1-parse/state/element.js
+++ b/packages/svelte/src/compiler/phases/1-parse/state/element.js
@@ -268,22 +268,41 @@ export default function tag(parser) {
 		if (name === 'script') {
 			const content = read_script(parser, start, element.attributes);
 
-			if (content) {
-				if (content.context === 'module') {
-					if (current.module) error(start, 'duplicate-script-element');
-					current.module = content;
-				} else {
-					if (current.instance) error(start, 'duplicate-script-element');
-					current.instance = content;
+			/** @type {import('#compiler').Comment | null} */
+			let prev_comment = null;
+			for (let i = current.fragment.nodes.length - 1; i >= 0; i--) {
+				const node = current.fragment.nodes[i];
+
+				if (i === current.fragment.nodes.length - 1 && node.end !== start) {
+					break;
 				}
+
+				if (node.type === 'Comment') {
+					prev_comment = node;
+					break;
+				} else if (node.type !== 'Text' || node.data.trim()) {
+					break;
+				}
+			}
+			if (prev_comment) {
+				// We take advantage of the fact that the root will never have leadingComments set,
+				// and set the previous comment to it so that the warning mechanism can later
+				// inspect the root and see if there was a html comment before it silencing specific warnings.
+				content.content.leadingComments = [{ type: 'Line', value: prev_comment.data }];
+			}
+
+			if (content.context === 'module') {
+				if (current.module) error(start, 'duplicate-script-element');
+				current.module = content;
+			} else {
+				if (current.instance) error(start, 'duplicate-script-element');
+				current.instance = content;
 			}
 		} else {
 			const content = read_style(parser, start, element.attributes);
 
-			if (content) {
-				if (current.css) error(start, 'duplicate-style-element');
-				current.css = content;
-			}
+			if (current.css) error(start, 'duplicate-style-element');
+			current.css = content;
 		}
 		return;
 	}
diff --git a/packages/svelte/src/compiler/phases/2-analyze/index.js b/packages/svelte/src/compiler/phases/2-analyze/index.js
index 04b3d72b8a..545fc90ecb 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/index.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/index.js
@@ -300,6 +300,25 @@ export function analyze_component(root, options) {
 					declaration.initial.source.value === 'svelte/store'
 				))
 		) {
+			let is_nested_store_subscription = false;
+			for (const reference of references) {
+				for (let i = reference.path.length - 1; i >= 0; i--) {
+					const scope =
+						scopes.get(reference.path[i]) ||
+						module.scopes.get(reference.path[i]) ||
+						instance.scopes.get(reference.path[i]);
+					if (scope) {
+						const owner = scope?.owner(store_name);
+						is_nested_store_subscription =
+							!!owner && owner !== module.scope && owner !== instance.scope;
+						break;
+					}
+				}
+			}
+			if (is_nested_store_subscription) {
+				error(references[0].node, 'illegal-store-subscription');
+			}
+
 			if (options.runes !== false) {
 				if (declaration === null && /[a-z]/.test(store_name[0])) {
 					error(references[0].node, 'illegal-global', name);
@@ -442,6 +461,17 @@ export function analyze_component(root, options) {
 			);
 		}
 
+		for (const [name, binding] of instance.scope.declarations) {
+			if (binding.kind === 'prop' && binding.node.name !== '$$props') {
+				const references = binding.references.filter(
+					(r) => r.node !== binding.node && r.path.at(-1)?.type !== 'ExportSpecifier'
+				);
+				if (!references.length && !instance.scope.declarations.has(`$${name}`)) {
+					warn(warnings, binding.node, [], 'unused-export-let', name);
+				}
+			}
+		}
+
 		analysis.reactive_statements = order_reactive_statements(analysis.reactive_statements);
 	}
 
@@ -590,6 +620,17 @@ const legacy_scope_tweaker = {
 
 		state.reactive_statements.set(node, reactive_statement);
 
+		// Ideally this would be in the validation file, but that isn't possible because this visitor
+		// calls "next" before setting the reactive statements.
+		if (
+			reactive_statement.dependencies.size &&
+			[...reactive_statement.dependencies].every(
+				(d) => d.scope === state.analysis.module.scope && d.declaration_kind !== 'const'
+			)
+		) {
+			warn(state.analysis.warnings, node, path, 'module-script-reactive-declaration');
+		}
+
 		if (
 			node.body.type === 'ExpressionStatement' &&
 			node.body.expression.type === 'AssignmentExpression'
@@ -710,7 +751,8 @@ const legacy_scope_tweaker = {
 				if (
 					binding.kind === 'state' ||
 					binding.kind === 'frozen_state' ||
-					(binding.kind === 'normal' && binding.declaration_kind === 'let')
+					(binding.kind === 'normal' &&
+						(binding.declaration_kind === 'let' || binding.declaration_kind === 'var'))
 				) {
 					binding.kind = 'prop';
 					if (specifier.exported.name !== specifier.local.name) {
diff --git a/packages/svelte/src/compiler/phases/2-analyze/validation.js b/packages/svelte/src/compiler/phases/2-analyze/validation.js
index 6bcfd7bb9a..9a09a1ea53 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/validation.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/validation.js
@@ -49,8 +49,12 @@ function validate_component(node, context) {
 			error(attribute, 'invalid-event-modifier');
 		}
 
-		if (attribute.type === 'Attribute' && attribute.name === 'slot') {
-			validate_slot_attribute(context, attribute);
+		if (attribute.type === 'Attribute') {
+			validate_attribute_name(attribute, context);
+
+			if (attribute.name === 'slot') {
+				validate_slot_attribute(context, attribute);
+			}
 		}
 	}
 
@@ -61,6 +65,11 @@ function validate_component(node, context) {
 	});
 }
 
+const react_attributes = new Map([
+	['className', 'class'],
+	['htmlFor', 'for']
+]);
+
 /**
  * @param {import('#compiler').RegularElement | import('#compiler').SvelteElement} node
  * @param {import('zimmerframe').Context<import('#compiler').SvelteNode, import('./types.js').AnalysisState>} context
@@ -105,6 +114,20 @@ function validate_element(node, context) {
 			if (attribute.name === 'is' && context.state.options.namespace !== 'foreign') {
 				warn(context.state.analysis.warnings, attribute, context.path, 'avoid-is');
 			}
+
+			const correct_name = react_attributes.get(attribute.name);
+			if (correct_name) {
+				warn(
+					context.state.analysis.warnings,
+					attribute,
+					context.path,
+					'invalid-html-attribute',
+					attribute.name,
+					correct_name
+				);
+			}
+
+			validate_attribute_name(attribute, context);
 		} else if (attribute.type === 'AnimateDirective') {
 			const parent = context.path.at(-2);
 			if (parent?.type !== 'EachBlock') {
@@ -166,6 +189,21 @@ function validate_element(node, context) {
 	}
 }
 
+/**
+ * @param {import('#compiler').Attribute} attribute
+ * @param {import('zimmerframe').Context<import('#compiler').SvelteNode, import('./types.js').AnalysisState>} context
+ */
+function validate_attribute_name(attribute, context) {
+	if (
+		attribute.name.includes(':') &&
+		!attribute.name.startsWith('xmlns:') &&
+		!attribute.name.startsWith('xlink:') &&
+		!attribute.name.startsWith('xml:')
+	) {
+		warn(context.state.analysis.warnings, attribute, context.path, 'illegal-attribute-character');
+	}
+}
+
 /**
  * @param {import('zimmerframe').Context<import('#compiler').SvelteNode, import('./types.js').AnalysisState>} context
  * @param {import('#compiler').Attribute} attribute
@@ -231,6 +269,19 @@ function validate_slot_attribute(context, attribute) {
 	}
 }
 
+/**
+ * @param {import('#compiler').Fragment | null | undefined} node
+ * @param {import('zimmerframe').Context<import('#compiler').SvelteNode, import('./types.js').AnalysisState>} context
+ */
+function validate_block_not_empty(node, context) {
+	if (!node) return;
+	// Assumption: If the block has zero elements, someone's in the middle of typing it out,
+	// so don't warn in that case because it would be distracting.
+	if (node.nodes.length === 1 && node.nodes[0].type === 'Text' && !node.nodes[0].raw.trim()) {
+		warn(context.state.analysis.warnings, node.nodes[0], context.path, 'empty-block');
+	}
+}
+
 /**
  * @type {import('zimmerframe').Visitors<import('#compiler').SvelteNode, import('./types.js').AnalysisState>}
  */
@@ -277,13 +328,24 @@ const validation = {
 			// TODO handle mutations of non-state/props in runes mode
 		}
 
+		const binding = context.state.scope.get(left.name);
+
 		if (node.name === 'group') {
-			const binding = context.state.scope.get(left.name);
 			if (!binding) {
 				error(node, 'INTERNAL', 'Cannot find declaration for bind:group');
 			}
 		}
 
+		if (binding?.kind === 'each' && binding.metadata?.inside_rest) {
+			warn(
+				context.state.analysis.warnings,
+				binding.node,
+				context.path,
+				'invalid-rest-eachblock-binding',
+				binding.node.name
+			);
+		}
+
 		const parent = context.path.at(-1);
 
 		if (
@@ -521,8 +583,28 @@ const validation = {
 			);
 		}
 	},
-	SnippetBlock(node, { path }) {
+	IfBlock(node, context) {
+		validate_block_not_empty(node.consequent, context);
+		validate_block_not_empty(node.alternate, context);
+	},
+	EachBlock(node, context) {
+		validate_block_not_empty(node.body, context);
+		validate_block_not_empty(node.fallback, context);
+	},
+	AwaitBlock(node, context) {
+		validate_block_not_empty(node.pending, context);
+		validate_block_not_empty(node.then, context);
+		validate_block_not_empty(node.catch, context);
+	},
+	KeyBlock(node, context) {
+		validate_block_not_empty(node.fragment, context);
+	},
+	SnippetBlock(node, context) {
+		validate_block_not_empty(node.body, context);
+
 		if (node.expression.name !== 'children') return;
+
+		const { path } = context;
 		const parent = path.at(-2);
 		if (!parent) return;
 		if (
@@ -539,6 +621,11 @@ const validation = {
 			}
 		}
 	},
+	StyleDirective(node) {
+		if (node.modifiers.length > 1 || (node.modifiers.length && node.modifiers[0] !== 'important')) {
+			error(node, 'invalid-style-directive-modifier');
+		}
+	},
 	SvelteHead(node) {
 		const attribute = node.attributes[0];
 		if (attribute) {
@@ -622,6 +709,8 @@ const validation = {
 
 export const validation_legacy = merge(validation, a11y_validators, {
 	VariableDeclarator(node, { state }) {
+		ensure_no_module_import_conflict(node, state);
+
 		if (node.init?.type !== 'CallExpression') return;
 
 		const callee = node.init.callee;
@@ -732,6 +821,22 @@ function validate_call_expression(node, scope, path) {
 	}
 }
 
+/**
+ * @param {import('estree').VariableDeclarator} node
+ * @param {import('./types.js').AnalysisState} state
+ */
+function ensure_no_module_import_conflict(node, state) {
+	const ids = extract_identifiers(node.id);
+	for (const id of ids) {
+		if (
+			state.scope === state.analysis.instance.scope &&
+			state.analysis.module.scope.get(id.name)?.declaration_kind === 'import'
+		) {
+			error(node.id, 'illegal-variable-declaration');
+		}
+	}
+}
+
 /**
  * @type {import('zimmerframe').Visitors<import('#compiler').SvelteNode, import('./types.js').AnalysisState>}
  */
@@ -912,6 +1017,8 @@ export const validation_runes = merge(validation, a11y_validators, {
 		next({ ...state });
 	},
 	VariableDeclarator(node, { state, path }) {
+		ensure_no_module_import_conflict(node, state);
+
 		const init = node.init;
 		const rune = get_rune(init, state.scope);
 
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/template.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/template.js
index 7c68026489..1550f2499f 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/template.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/template.js
@@ -1800,6 +1800,12 @@ export const template_visitors = {
 					)
 				)
 			);
+
+			// we need to eagerly evaluate the expression in order to hit any
+			// 'Cannot access x before initialization' errors
+			if (state.options.dev) {
+				state.init.push(b.stmt(b.call('$.get', declaration.id)));
+			}
 		} else {
 			const identifiers = extract_identifiers(declaration.id);
 			const tmp = b.id(state.scope.generate('computed_const'));
@@ -1829,6 +1835,12 @@ export const template_visitors = {
 				b.const(tmp, b.call(state.options.runes ? '$.derived' : '$.derived_safe_equal', fn))
 			);
 
+			// we need to eagerly evaluate the expression in order to hit any
+			// 'Cannot access x before initialization' errors
+			if (state.options.dev) {
+				state.init.push(b.stmt(b.call('$.get', tmp)));
+			}
+
 			for (const node of identifiers) {
 				const binding = /** @type {import('#compiler').Binding} */ (state.scope.get(node.name));
 				binding.expression = b.member(b.call('$.get', tmp), node);
diff --git a/packages/svelte/src/compiler/phases/scope.js b/packages/svelte/src/compiler/phases/scope.js
index dea556f9c8..cecd52bda8 100644
--- a/packages/svelte/src/compiler/phases/scope.js
+++ b/packages/svelte/src/compiler/phases/scope.js
@@ -14,7 +14,7 @@ export class Scope {
 	 * The immediate parent scope
 	 * @type {Scope | null}
 	 */
-	#parent;
+	parent;
 
 	/**
 	 * Whether or not `var` declarations are contained by this scope
@@ -56,7 +56,7 @@ export class Scope {
 	 */
 	constructor(root, parent, porous) {
 		this.root = root;
-		this.#parent = parent;
+		this.parent = parent;
 		this.#porous = porous;
 		this.function_depth = parent ? parent.function_depth + (porous ? 0 : 1) : 0;
 	}
@@ -83,13 +83,13 @@ export class Scope {
 			error(node, 'invalid-dollar-prefix');
 		}
 
-		if (this.#parent) {
+		if (this.parent) {
 			if (declaration_kind === 'var' && this.#porous) {
-				return this.#parent.declare(node, kind, declaration_kind);
+				return this.parent.declare(node, kind, declaration_kind);
 			}
 
 			if (declaration_kind === 'import') {
-				return this.#parent.declare(node, kind, declaration_kind, initial);
+				return this.parent.declare(node, kind, declaration_kind, initial);
 			}
 		}
 
@@ -112,7 +112,8 @@ export class Scope {
 			prop_alias: null,
 			expression: null,
 			mutation: null,
-			reassigned: false
+			reassigned: false,
+			metadata: null
 		};
 		this.declarations.set(node.name, binding);
 		this.root.conflicts.add(node.name);
@@ -129,7 +130,7 @@ export class Scope {
 	 */
 	generate(preferred_name) {
 		if (this.#porous) {
-			return /** @type {Scope} */ (this.#parent).generate(preferred_name);
+			return /** @type {Scope} */ (this.parent).generate(preferred_name);
 		}
 
 		preferred_name = preferred_name.replace(/[^a-zA-Z0-9_$]/g, '_').replace(/^[0-9]/, '_');
@@ -155,7 +156,7 @@ export class Scope {
 	 * @returns {import('#compiler').Binding | null}
 	 */
 	get(name) {
-		return this.declarations.get(name) ?? this.#parent?.get(name) ?? null;
+		return this.declarations.get(name) ?? this.parent?.get(name) ?? null;
 	}
 
 	/**
@@ -175,7 +176,7 @@ export class Scope {
 	 * @returns {Scope | null}
 	 */
 	owner(name) {
-		return this.declarations.has(name) ? this : this.#parent && this.#parent.owner(name);
+		return this.declarations.has(name) ? this : this.parent && this.parent.owner(name);
 	}
 
 	/**
@@ -193,8 +194,8 @@ export class Scope {
 		const binding = this.declarations.get(node.name);
 		if (binding) {
 			binding.references.push({ node, path });
-		} else if (this.#parent) {
-			this.#parent.reference(node, path);
+		} else if (this.parent) {
+			this.parent.reference(node, path);
 		} else {
 			// no binding was found, and this is the top level scope,
 			// which means this is a global
@@ -534,11 +535,31 @@ export function create_scopes(ast, root, allow_reactive_declarations, parent) {
 
 			// declarations
 			for (const id of extract_identifiers(node.context)) {
-				scope.declare(id, 'each', 'const');
+				const binding = scope.declare(id, 'each', 'const');
+
+				let inside_rest = false;
+				let is_rest_id = false;
+				walk(node.context, null, {
+					Identifier(node) {
+						if (inside_rest && node === id) {
+							is_rest_id = true;
+						}
+					},
+					RestElement(_, { next }) {
+						const prev = inside_rest;
+						inside_rest = true;
+						next();
+						inside_rest = prev;
+					}
+				});
+
+				binding.metadata = { inside_rest: is_rest_id };
 			}
 			if (node.context.type !== 'Identifier') {
 				scope.declare(b.id('$$item'), 'derived', 'synthetic');
 			}
+			// Visit to pick up references from default initializers
+			visit(node.context, { scope });
 
 			if (node.index) {
 				const is_keyed =
diff --git a/packages/svelte/src/compiler/types/index.d.ts b/packages/svelte/src/compiler/types/index.d.ts
index 11e71f63a1..a04d1c39af 100644
--- a/packages/svelte/src/compiler/types/index.d.ts
+++ b/packages/svelte/src/compiler/types/index.d.ts
@@ -288,6 +288,11 @@ export interface Binding {
 	expression: Expression | ((id: Identifier) => Expression) | null;
 	/** If this is set, all mutations should use this expression */
 	mutation: ((assignment: AssignmentExpression, context: Context<any, any>) => Expression) | null;
+	/** Additional metadata, varies per binding type */
+	metadata: {
+		/** `true` if is (inside) a rest parameter */
+		inside_rest?: boolean;
+	} | null;
 }
 
 export * from './template.js';
diff --git a/packages/svelte/src/compiler/types/template.d.ts b/packages/svelte/src/compiler/types/template.d.ts
index 5d794cee09..b714370b6d 100644
--- a/packages/svelte/src/compiler/types/template.d.ts
+++ b/packages/svelte/src/compiler/types/template.d.ts
@@ -13,12 +13,9 @@ import type {
 	ObjectExpression,
 	Pattern,
 	Program,
-	SpreadElement,
-	CallExpression,
 	ChainExpression,
 	SimpleCallExpression
 } from 'estree';
-import type { Atrule, Rule } from './css';
 
 export interface BaseNode {
 	type: string;
diff --git a/packages/svelte/src/compiler/warnings.js b/packages/svelte/src/compiler/warnings.js
index 20375bca76..1dd7e2aac9 100644
--- a/packages/svelte/src/compiler/warnings.js
+++ b/packages/svelte/src/compiler/warnings.js
@@ -15,7 +15,15 @@ const attributes = {
 	'avoid-is': () => 'The "is" attribute is not supported cross-browser and should be avoided',
 	/** @param {string} name */
 	'global-event-reference': (name) =>
-		`You are referencing globalThis.${name}. Did you forget to declare a variable with that name?`
+		`You are referencing globalThis.${name}. Did you forget to declare a variable with that name?`,
+	'illegal-attribute-character': () =>
+		"Attributes should not contain ':' characters to prevent ambiguity with Svelte directives",
+	/**
+	 * @param {string} wrong
+	 * @param {string} right
+	 */
+	'invalid-html-attribute': (wrong, right) =>
+		`'${wrong}' is not a valid HTML attribute. Did you mean '${right}'?`
 };
 
 /** @satisfies {Warnings} */
@@ -195,7 +203,10 @@ const a11y = {
 /** @satisfies {Warnings} */
 const state = {
 	'static-state-reference': () =>
-		`State referenced in its own scope will never update. Did you mean to reference it inside a closure?`
+		`State referenced in its own scope will never update. Did you mean to reference it inside a closure?`,
+	/** @param {string} name */
+	'invalid-rest-eachblock-binding': (name) =>
+		`The rest operator (...) will create a new object and binding '${name}' with the original object will not work`
 };
 
 /** @satisfies {Warnings} */
@@ -214,7 +225,16 @@ const components = {
 
 const legacy = {
 	'no-reactive-declaration': () =>
-		`Reactive declarations only exist at the top level of the instance script`
+		`Reactive declarations only exist at the top level of the instance script`,
+	'module-script-reactive-declaration': () =>
+		'All dependencies of the reactive declaration are declared in a module script and will not be reactive',
+	/** @param {string} name */
+	'unused-export-let': (name) =>
+		`Component has unused export property '${name}'. If it is for external reference only, please consider using \`export const ${name}\``
+};
+
+const block = {
+	'empty-block': () => 'Empty block'
 };
 
 /** @satisfies {Warnings} */
@@ -226,7 +246,8 @@ const warnings = {
 	...performance,
 	...state,
 	...components,
-	...legacy
+	...legacy,
+	...block
 };
 
 /** @typedef {typeof warnings} AllWarnings */
@@ -234,7 +255,7 @@ const warnings = {
 /**
  * @template {keyof AllWarnings} T
  * @param {import('./phases/types').RawWarning[]} array the array to push the warning to, if not ignored
- * @param {{ start?: number, end?: number, parent?: import('#compiler').SvelteNode | null, leadingComments?: import('estree').Comment[] } | null} node the node related to the warning
+ * @param {{ start?: number, end?: number, type?: string, parent?: import('#compiler').SvelteNode | null, leadingComments?: import('estree').Comment[] } | null} node the node related to the warning
  * @param {import('#compiler').SvelteNode[]} path the path to the node, so that we can traverse upwards to find svelte-ignore comments
  * @param {T} code the warning code
  * @param  {Parameters<AllWarnings[T]>} args the arguments to pass to the warning function
@@ -249,6 +270,13 @@ export function warn(array, node, path, code, ...args) {
 	/** @type {string[]} */
 	const ignores = [];
 
+	if (node) {
+		// comments inside JavaScript (estree)
+		if ('leadingComments' in node) {
+			ignores.push(...extract_svelte_ignore_from_comments(node));
+		}
+	}
+
 	for (let i = path.length - 1; i >= 0; i--) {
 		const current = path[i];
 
diff --git a/packages/svelte/tests/compiler-errors/samples/store-contextual/_config.js b/packages/svelte/tests/compiler-errors/samples/store-contextual/_config.js
index 8b7bf1afb1..2a7d0fa0ec 100644
--- a/packages/svelte/tests/compiler-errors/samples/store-contextual/_config.js
+++ b/packages/svelte/tests/compiler-errors/samples/store-contextual/_config.js
@@ -1,10 +1,8 @@
 import { test } from '../../test';
 
 export default test({
-	skip: true,
 	error: {
-		code: '',
-		message:
-			'Stores must be declared at the top level of the component (this may change in a future version of Svelte)'
+		code: 'illegal-store-subscription',
+		message: 'Cannot subscribe to stores that are not declared at the top level of the component'
 	}
 });
diff --git a/packages/svelte/tests/compiler-errors/samples/store-prevent-user-declarations/_config.js b/packages/svelte/tests/compiler-errors/samples/store-prevent-user-declarations/_config.js
index ea6e7b5d4f..97bc9d4c3d 100644
--- a/packages/svelte/tests/compiler-errors/samples/store-prevent-user-declarations/_config.js
+++ b/packages/svelte/tests/compiler-errors/samples/store-prevent-user-declarations/_config.js
@@ -1,9 +1,8 @@
 import { test } from '../../test';
 
 export default test({
-	skip: true,
 	error: {
-		code: '',
-		message: 'The $ prefix is reserved, and cannot be used for variable and import names'
+		code: 'invalid-dollar-prefix',
+		message: 'The $ prefix is reserved, and cannot be used for variables and imports'
 	}
 });
diff --git a/packages/svelte/tests/compiler-errors/samples/store-shadow-scope/_config.js b/packages/svelte/tests/compiler-errors/samples/store-shadow-scope/_config.js
index 8b7bf1afb1..2a7d0fa0ec 100644
--- a/packages/svelte/tests/compiler-errors/samples/store-shadow-scope/_config.js
+++ b/packages/svelte/tests/compiler-errors/samples/store-shadow-scope/_config.js
@@ -1,10 +1,8 @@
 import { test } from '../../test';
 
 export default test({
-	skip: true,
 	error: {
-		code: '',
-		message:
-			'Stores must be declared at the top level of the component (this may change in a future version of Svelte)'
+		code: 'illegal-store-subscription',
+		message: 'Cannot subscribe to stores that are not declared at the top level of the component'
 	}
 });
diff --git a/packages/svelte/tests/compiler-errors/samples/store-template-expression-scope/_config.js b/packages/svelte/tests/compiler-errors/samples/store-template-expression-scope/_config.js
index 8b7bf1afb1..2a7d0fa0ec 100644
--- a/packages/svelte/tests/compiler-errors/samples/store-template-expression-scope/_config.js
+++ b/packages/svelte/tests/compiler-errors/samples/store-template-expression-scope/_config.js
@@ -1,10 +1,8 @@
 import { test } from '../../test';
 
 export default test({
-	skip: true,
 	error: {
-		code: '',
-		message:
-			'Stores must be declared at the top level of the component (this may change in a future version of Svelte)'
+		code: 'illegal-store-subscription',
+		message: 'Cannot subscribe to stores that are not declared at the top level of the component'
 	}
 });
diff --git a/packages/svelte/tests/parser-modern/samples/comment-before-script/output.json b/packages/svelte/tests/parser-modern/samples/comment-before-script/output.json
index d52a3752b4..4891e70c92 100644
--- a/packages/svelte/tests/parser-modern/samples/comment-before-script/output.json
+++ b/packages/svelte/tests/parser-modern/samples/comment-before-script/output.json
@@ -44,6 +44,7 @@
 					"column": 0
 				}
 			},
+			"leadingComments": [{ "type": "Line", "value": "should not error out" }],
 			"body": [
 				{
 					"type": "VariableDeclaration",
diff --git a/packages/svelte/tests/runtime-legacy/samples/const-tag-used-before-initialised copy/_config.js b/packages/svelte/tests/runtime-legacy/samples/const-tag-used-before-initialised copy/_config.js
new file mode 100644
index 0000000000..b086f7cdf8
--- /dev/null
+++ b/packages/svelte/tests/runtime-legacy/samples/const-tag-used-before-initialised copy/_config.js	
@@ -0,0 +1,9 @@
+import { test } from '../../test';
+
+export default test({
+	compileOptions: {
+		dev: true
+	},
+
+	error: "Cannot access 'c' before initialization"
+});
diff --git a/packages/svelte/tests/validator/samples/const-tag-cyclical/input.svelte b/packages/svelte/tests/runtime-legacy/samples/const-tag-used-before-initialised copy/main.svelte
similarity index 70%
rename from packages/svelte/tests/validator/samples/const-tag-cyclical/input.svelte
rename to packages/svelte/tests/runtime-legacy/samples/const-tag-used-before-initialised copy/main.svelte
index 2f694be808..746374b44f 100644
--- a/packages/svelte/tests/validator/samples/const-tag-cyclical/input.svelte
+++ b/packages/svelte/tests/runtime-legacy/samples/const-tag-used-before-initialised copy/main.svelte	
@@ -1,8 +1,8 @@
 <script>
-  export let array;
+  export let array = [1];
 </script>
 
 {#each array as a}
   {@const b = a + c}
   {@const c = b + a}
-{/each}
\ No newline at end of file
+{/each}
diff --git a/packages/svelte/tests/validator/samples/const-tag-cyclical/_config.js b/packages/svelte/tests/validator/samples/const-tag-cyclical/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/const-tag-cyclical/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/const-tag-cyclical/errors.json b/packages/svelte/tests/validator/samples/const-tag-cyclical/errors.json
deleted file mode 100644
index 2b13e575cf..0000000000
--- a/packages/svelte/tests/validator/samples/const-tag-cyclical/errors.json
+++ /dev/null
@@ -1,8 +0,0 @@
-[
-	{
-		"code": "cyclical-const-tags",
-		"message": "Cyclical dependency detected: b → c → b",
-		"start": { "line": 6, "column": 2 },
-		"end": { "line": 6, "column": 20 }
-	}
-]
diff --git a/packages/svelte/tests/validator/samples/empty-block/_config.js b/packages/svelte/tests/validator/samples/empty-block/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/empty-block/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/empty-block/input.svelte b/packages/svelte/tests/validator/samples/empty-block/input.svelte
index 4185f4f817..6c2da0ffeb 100644
--- a/packages/svelte/tests/validator/samples/empty-block/input.svelte
+++ b/packages/svelte/tests/validator/samples/empty-block/input.svelte
@@ -2,8 +2,17 @@
 	let things = [];
 </script>
 
+<!-- ok (zero elements very likely means someone's in the middle of typing) -->
+{#each things as thing}{/each}
+{#if true}{/if}
+{#key things}x{/key}
+{#await promise}{things}
+{/await}
+
+<!-- invalid -->
 {#each things as thing}
 
 {/each}
-
-{#each things as thing}{/each}
\ No newline at end of file
+{#if true} {/if}
+{#key things} {/key}
+{#await promise} {/await}
diff --git a/packages/svelte/tests/validator/samples/empty-block/warnings.json b/packages/svelte/tests/validator/samples/empty-block/warnings.json
index 11ca8e204e..b86dab6f72 100644
--- a/packages/svelte/tests/validator/samples/empty-block/warnings.json
+++ b/packages/svelte/tests/validator/samples/empty-block/warnings.json
@@ -2,25 +2,25 @@
 	{
 		"code": "empty-block",
 		"message": "Empty block",
-		"start": {
-			"line": 5,
-			"column": 0
-		},
-		"end": {
-			"line": 7,
-			"column": 7
-		}
+		"start": { "line": 13, "column": 23 },
+		"end": { "line": 15, "column": 0 }
 	},
 	{
 		"code": "empty-block",
 		"message": "Empty block",
-		"start": {
-			"line": 9,
-			"column": 0
-		},
-		"end": {
-			"line": 9,
-			"column": 30
-		}
+		"start": { "line": 16, "column": 10 },
+		"end": { "line": 16, "column": 11 }
+	},
+	{
+		"code": "empty-block",
+		"message": "Empty block",
+		"start": { "line": 17, "column": 13 },
+		"end": { "line": 17, "column": 14 }
+	},
+	{
+		"code": "empty-block",
+		"message": "Empty block",
+		"start": { "line": 18, "column": 16 },
+		"end": { "line": 18, "column": 17 }
 	}
 ]
diff --git a/packages/svelte/tests/validator/samples/event-modifiers-redundant/_config.js b/packages/svelte/tests/validator/samples/event-modifiers-redundant/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/event-modifiers-redundant/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/event-modifiers-redundant/input.svelte b/packages/svelte/tests/validator/samples/event-modifiers-redundant/input.svelte
deleted file mode 100644
index 3161674beb..0000000000
--- a/packages/svelte/tests/validator/samples/event-modifiers-redundant/input.svelte
+++ /dev/null
@@ -1,12 +0,0 @@
-<script>
-	function handleTouchstart() {
-		// ...
-	}
-
-	function handleClick() {
-		// ...
-	}
-</script>
-
-<button on:click|passive="{handleClick}"></button>
-<div on:touchstart|passive="{handleTouchstart}"></div>
\ No newline at end of file
diff --git a/packages/svelte/tests/validator/samples/event-modifiers-redundant/warnings.json b/packages/svelte/tests/validator/samples/event-modifiers-redundant/warnings.json
deleted file mode 100644
index e5ff27b728..0000000000
--- a/packages/svelte/tests/validator/samples/event-modifiers-redundant/warnings.json
+++ /dev/null
@@ -1,26 +0,0 @@
-[
-	{
-		"message": "The passive modifier only works with wheel and touch events",
-		"code": "redundant-event-modifier",
-		"start": {
-			"line": 11,
-			"column": 8
-		},
-		"end": {
-			"line": 11,
-			"column": 40
-		}
-	},
-	{
-		"message": "Touch event handlers that don't use the 'event' object are passive by default",
-		"code": "redundant-event-modifier",
-		"start": {
-			"line": 12,
-			"column": 5
-		},
-		"end": {
-			"line": 12,
-			"column": 47
-		}
-	}
-]
diff --git a/packages/svelte/tests/validator/samples/illegal-attribute-character/_config.js b/packages/svelte/tests/validator/samples/illegal-attribute-character/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/illegal-attribute-character/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/illegal-variable-declaration/_config.js b/packages/svelte/tests/validator/samples/illegal-variable-declaration/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/illegal-variable-declaration/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/illegal-variable-declaration/errors.json b/packages/svelte/tests/validator/samples/illegal-variable-declaration/errors.json
index 606fa5e0a6..788784d1d8 100644
--- a/packages/svelte/tests/validator/samples/illegal-variable-declaration/errors.json
+++ b/packages/svelte/tests/validator/samples/illegal-variable-declaration/errors.json
@@ -3,12 +3,12 @@
 		"code": "illegal-variable-declaration",
 		"message": "Cannot declare same variable name which is imported inside <script context=\"module\">",
 		"start": {
-			"line": 6,
-			"column": 1
+			"line": 12,
+			"column": 5
 		},
 		"end": {
-			"line": 6,
-			"column": 9
+			"line": 12,
+			"column": 8
 		}
 	}
 ]
diff --git a/packages/svelte/tests/validator/samples/illegal-variable-declaration/input.svelte b/packages/svelte/tests/validator/samples/illegal-variable-declaration/input.svelte
index 4542380f49..0655ea322d 100644
--- a/packages/svelte/tests/validator/samples/illegal-variable-declaration/input.svelte
+++ b/packages/svelte/tests/validator/samples/illegal-variable-declaration/input.svelte
@@ -1,8 +1,14 @@
 <script context="module">
 	import { FOO } from './dummy.svelte';
+	function ok() {
+		let FOO;
+	}
 </script>
 
 <script>
+	function ok() {
+		let FOO;
+	}
 	let FOO;
 </script>
 
diff --git a/packages/svelte/tests/validator/samples/invalid-empty-css-declaration/_config.js b/packages/svelte/tests/validator/samples/invalid-empty-css-declaration/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/invalid-empty-css-declaration/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/invalid-empty-css-declaration/errors.json b/packages/svelte/tests/validator/samples/invalid-empty-css-declaration/errors.json
index 5d37ddccf0..2ceb3a3694 100644
--- a/packages/svelte/tests/validator/samples/invalid-empty-css-declaration/errors.json
+++ b/packages/svelte/tests/validator/samples/invalid-empty-css-declaration/errors.json
@@ -1,14 +1,14 @@
 [
 	{
-		"code": "invalid-declaration",
+		"code": "invalid-css-declaration",
 		"message": "Declaration cannot be empty",
 		"start": {
-			"line": 11,
-			"column": 0
+			"line": 5,
+			"column": 8
 		},
 		"end": {
-			"line": 11,
-			"column": 0
+			"line": 5,
+			"column": 8
 		}
 	}
 ]
diff --git a/packages/svelte/tests/validator/samples/invalid-reactive-var-1/_config.js b/packages/svelte/tests/validator/samples/invalid-reactive-var-1/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/invalid-reactive-var-1/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/invalid-reactive-var-1/errors.json b/packages/svelte/tests/validator/samples/invalid-reactive-var-1/errors.json
deleted file mode 100644
index 35fb5b14d0..0000000000
--- a/packages/svelte/tests/validator/samples/invalid-reactive-var-1/errors.json
+++ /dev/null
@@ -1,8 +0,0 @@
-[
-	{
-		"code": "invalid_var_declaration",
-		"message": "\"var\" scope should not extend outside the reactive block",
-		"start": { "line": 14, "column": 7 },
-		"end": { "line": 14, "column": 16 }
-	}
-]
diff --git a/packages/svelte/tests/validator/samples/invalid-reactive-var-1/input.svelte b/packages/svelte/tests/validator/samples/invalid-reactive-var-1/input.svelte
deleted file mode 100644
index 7fe774959d..0000000000
--- a/packages/svelte/tests/validator/samples/invalid-reactive-var-1/input.svelte
+++ /dev/null
@@ -1,20 +0,0 @@
-<script>
-	var a;
-	var {a, b: [d, f], c}= {a: 1, b: [1, 2], c: 2};
-	$: {
-		function one() {
-			var a = 'a';
-			function two() {
-				var a = 'b';
-				return a;
-			}
-			return two();
-		}
-		a = one();
-		for (var i = 0; i<5; i ++ ) {
-			// Todo
-		}
-	}
-</script>
-
-<h1>Hello {a}</h1>
diff --git a/packages/svelte/tests/validator/samples/invalid-reactive-var-2/_config.js b/packages/svelte/tests/validator/samples/invalid-reactive-var-2/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/invalid-reactive-var-2/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/invalid-reactive-var-2/errors.json b/packages/svelte/tests/validator/samples/invalid-reactive-var-2/errors.json
deleted file mode 100644
index 3bc0802718..0000000000
--- a/packages/svelte/tests/validator/samples/invalid-reactive-var-2/errors.json
+++ /dev/null
@@ -1,8 +0,0 @@
-[
-	{
-		"code": "invalid_var_declaration",
-		"message": "\"var\" scope should not extend outside the reactive block",
-		"start": { "line": 4, "column": 2 },
-		"end": { "line": 4, "column": 50 }
-	}
-]
diff --git a/packages/svelte/tests/validator/samples/invalid-reactive-var-2/input.svelte b/packages/svelte/tests/validator/samples/invalid-reactive-var-2/input.svelte
deleted file mode 100644
index b3a1c4272c..0000000000
--- a/packages/svelte/tests/validator/samples/invalid-reactive-var-2/input.svelte
+++ /dev/null
@@ -1,8 +0,0 @@
-<script>
-	$: {
-		let f = 'f';
-		var {a, b: [c, d], e} = {a: 1, b: [2, 3], e: 4};
-	}
-</script>
-
-<h1>Hello</h1>
diff --git a/packages/svelte/tests/validator/samples/reactive-module-variable/_config.js b/packages/svelte/tests/validator/samples/reactive-module-variable/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/reactive-module-variable/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/reactive-module-variable/warnings.json b/packages/svelte/tests/validator/samples/reactive-module-variable/warnings.json
index 5fb84a8505..60701e30b7 100644
--- a/packages/svelte/tests/validator/samples/reactive-module-variable/warnings.json
+++ b/packages/svelte/tests/validator/samples/reactive-module-variable/warnings.json
@@ -1,9 +1,9 @@
 [
 	{
 		"code": "module-script-reactive-declaration",
-		"message": "\"foo\" is declared in a module script and will not be reactive",
+		"message": "All dependencies of the reactive declaration are declared in a module script and will not be reactive",
 		"start": {
-			"column": 4,
+			"column": 1,
 			"line": 5
 		},
 		"end": {
diff --git a/packages/svelte/tests/validator/samples/rest-eachblock-binding-2/_config.js b/packages/svelte/tests/validator/samples/rest-eachblock-binding-2/_config.js
deleted file mode 100644
index 7fc1f9f61b..0000000000
--- a/packages/svelte/tests/validator/samples/rest-eachblock-binding-2/_config.js
+++ /dev/null
@@ -1,4 +0,0 @@
-import { test } from '../../test';
-
-// TODO this likely works in the new world - remove this warning?
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/rest-eachblock-binding-3/_config.js b/packages/svelte/tests/validator/samples/rest-eachblock-binding-3/_config.js
deleted file mode 100644
index 7fc1f9f61b..0000000000
--- a/packages/svelte/tests/validator/samples/rest-eachblock-binding-3/_config.js
+++ /dev/null
@@ -1,4 +0,0 @@
-import { test } from '../../test';
-
-// TODO this likely works in the new world - remove this warning?
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/rest-eachblock-binding-nested-rest/_config.js b/packages/svelte/tests/validator/samples/rest-eachblock-binding-nested-rest/_config.js
deleted file mode 100644
index a7d521e510..0000000000
--- a/packages/svelte/tests/validator/samples/rest-eachblock-binding-nested-rest/_config.js
+++ /dev/null
@@ -1,4 +0,0 @@
-import { test } from '../../test';
-
-// TODO this maybe works in the new world - remove this warning?
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/rest-eachblock-binding/_config.js b/packages/svelte/tests/validator/samples/rest-eachblock-binding/_config.js
deleted file mode 100644
index 7fc1f9f61b..0000000000
--- a/packages/svelte/tests/validator/samples/rest-eachblock-binding/_config.js
+++ /dev/null
@@ -1,4 +0,0 @@
-import { test } from '../../test';
-
-// TODO this likely works in the new world - remove this warning?
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/silence-warnings-2/input.svelte b/packages/svelte/tests/validator/samples/silence-warnings-2/input.svelte
index 81cb90b7be..e043fdafd3 100644
--- a/packages/svelte/tests/validator/samples/silence-warnings-2/input.svelte
+++ b/packages/svelte/tests/validator/samples/silence-warnings-2/input.svelte
@@ -2,8 +2,7 @@
 	let foo;
 </script>
 
-<!-- svelte-ignore unused-export-let module-script-reactive-declaration -->
+<!-- svelte-ignore module-script-reactive-declaration -->
 <script>
-	export let unused;
 	$: reactive = foo;
 </script>
diff --git a/packages/svelte/tests/validator/samples/silence-warnings/input.svelte b/packages/svelte/tests/validator/samples/silence-warnings/input.svelte
index 0e473f51db..8e1608d837 100644
--- a/packages/svelte/tests/validator/samples/silence-warnings/input.svelte
+++ b/packages/svelte/tests/validator/samples/silence-warnings/input.svelte
@@ -3,8 +3,6 @@
 </script>
 
 <script>
-	// svelte-ignore unused-export-let
-	export let unused;
 	// svelte-ignore module-script-reactive-declaration
 	$: reactive = foo;
 </script>
diff --git a/packages/svelte/tests/validator/samples/style-directive-modifiers-invalid/_config.js b/packages/svelte/tests/validator/samples/style-directive-modifiers-invalid/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/style-directive-modifiers-invalid/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/style-directive-modifiers-invalid/errors.json b/packages/svelte/tests/validator/samples/style-directive-modifiers-invalid/errors.json
index ef7d27a1f6..ba88102f40 100644
--- a/packages/svelte/tests/validator/samples/style-directive-modifiers-invalid/errors.json
+++ b/packages/svelte/tests/validator/samples/style-directive-modifiers-invalid/errors.json
@@ -1,6 +1,6 @@
 [
 	{
-		"message": "Valid modifiers for style directives are: important",
+		"message": "Invalid 'style:' modifier. Valid modifiers are: 'important'",
 		"code": "invalid-style-directive-modifier",
 		"start": {
 			"line": 1,
diff --git a/packages/svelte/tests/validator/samples/tag-invalid/_config.js b/packages/svelte/tests/validator/samples/tag-invalid/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/tag-invalid/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/tag-invalid/errors.json b/packages/svelte/tests/validator/samples/tag-invalid/errors.json
index 3b479c7c58..7fc929b226 100644
--- a/packages/svelte/tests/validator/samples/tag-invalid/errors.json
+++ b/packages/svelte/tests/validator/samples/tag-invalid/errors.json
@@ -1,7 +1,7 @@
 [
 	{
 		"code": "invalid-tag-property",
-		"message": "tag name must be two or more words joined by the '-' character",
+		"message": "tag name must be two or more words joined by the \"-\" character",
 		"start": {
 			"line": 1,
 			"column": 16
diff --git a/packages/svelte/tests/validator/samples/tag-non-string/_config.js b/packages/svelte/tests/validator/samples/tag-non-string/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/tag-non-string/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/tag-non-string/errors.json b/packages/svelte/tests/validator/samples/tag-non-string/errors.json
index aba8b9bc95..46c98b70d5 100644
--- a/packages/svelte/tests/validator/samples/tag-non-string/errors.json
+++ b/packages/svelte/tests/validator/samples/tag-non-string/errors.json
@@ -1,14 +1,14 @@
 [
 	{
-		"code": "invalid-tag-attribute",
-		"message": "'tag' must be a string literal",
+		"code": "invalid-svelte-option-customElement",
+		"message": "\"customElement\" must be a string literal defining a valid custom element name or an object of the form { tag: string; shadow?: \"open\" | \"none\"; props?: { [key: string]: { attribute?: string; reflect?: boolean; type: .. } } }",
 		"start": {
 			"line": 1,
 			"column": 16
 		},
 		"end": {
 			"line": 1,
-			"column": 24
+			"column": 34
 		}
 	}
 ]
diff --git a/packages/svelte/tests/validator/samples/tag-non-string/input.svelte b/packages/svelte/tests/validator/samples/tag-non-string/input.svelte
index 168b3ca031..feee8a706a 100644
--- a/packages/svelte/tests/validator/samples/tag-non-string/input.svelte
+++ b/packages/svelte/tests/validator/samples/tag-non-string/input.svelte
@@ -1 +1 @@
-<svelte:options tag={42}/>
+<svelte:options customElement={42}/>
diff --git a/packages/svelte/tests/validator/samples/unreferenced-variables-each/_config.js b/packages/svelte/tests/validator/samples/unreferenced-variables-each/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/unreferenced-variables-each/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/unreferenced-variables-each/warnings.json b/packages/svelte/tests/validator/samples/unreferenced-variables-each/warnings.json
index d66d0dc978..e8791eb61e 100644
--- a/packages/svelte/tests/validator/samples/unreferenced-variables-each/warnings.json
+++ b/packages/svelte/tests/validator/samples/unreferenced-variables-each/warnings.json
@@ -1,7 +1,7 @@
 [
 	{
 		"code": "unused-export-let",
-		"message": "Component_1 has unused export property 'default_value_5'. If it is for external reference only, please consider using `export const default_value_5`",
+		"message": "Component has unused export property 'default_value_5'. If it is for external reference only, please consider using `export const default_value_5`",
 		"start": {
 			"column": 12,
 			"line": 8
@@ -13,7 +13,7 @@
 	},
 	{
 		"code": "unused-export-let",
-		"message": "Component_1 has unused export property 'default_value_6'. If it is for external reference only, please consider using `export const default_value_6`",
+		"message": "Component has unused export property 'default_value_6'. If it is for external reference only, please consider using `export const default_value_6`",
 		"start": {
 			"column": 12,
 			"line": 9
diff --git a/packages/svelte/tests/validator/samples/unreferenced-variables/_config.js b/packages/svelte/tests/validator/samples/unreferenced-variables/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/unreferenced-variables/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/tests/validator/samples/unreferenced-variables/warnings.json b/packages/svelte/tests/validator/samples/unreferenced-variables/warnings.json
index e96a81e0dc..9690e557ec 100644
--- a/packages/svelte/tests/validator/samples/unreferenced-variables/warnings.json
+++ b/packages/svelte/tests/validator/samples/unreferenced-variables/warnings.json
@@ -2,31 +2,31 @@
 	{
 		"code": "unused-export-let",
 		"end": {
-			"column": 13,
-			"line": 31
+			"column": 8,
+			"line": 28
 		},
 		"message": "Component has unused export property 'd2'. If it is for external reference only, please consider using `export const d2`",
 		"start": {
-			"column": 11,
-			"line": 31
+			"column": 6,
+			"line": 28
 		}
 	},
 	{
 		"code": "unused-export-let",
 		"end": {
-			"column": 17,
-			"line": 31
+			"column": 8,
+			"line": 29
 		},
 		"message": "Component has unused export property 'e2'. If it is for external reference only, please consider using `export const e2`",
 		"start": {
-			"column": 15,
-			"line": 31
+			"column": 6,
+			"line": 29
 		}
 	},
 	{
 		"code": "unused-export-let",
 		"end": {
-			"column": 19,
+			"column": 15,
 			"line": 32
 		},
 		"message": "Component has unused export property 'g2'. If it is for external reference only, please consider using `export const g2`",
@@ -38,7 +38,7 @@
 	{
 		"code": "unused-export-let",
 		"end": {
-			"column": 19,
+			"column": 15,
 			"line": 33
 		},
 		"message": "Component has unused export property 'h2'. If it is for external reference only, please consider using `export const h2`",
@@ -50,7 +50,7 @@
 	{
 		"code": "unused-export-let",
 		"end": {
-			"column": 26,
+			"column": 15,
 			"line": 35
 		},
 		"message": "Component has unused export property 'j2'. If it is for external reference only, please consider using `export const j2`",
diff --git a/packages/svelte/tests/validator/samples/use-the-platform/_config.js b/packages/svelte/tests/validator/samples/use-the-platform/_config.js
deleted file mode 100644
index 64fdc120d6..0000000000
--- a/packages/svelte/tests/validator/samples/use-the-platform/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import { test } from '../../test';
-
-export default test({ skip: true });
diff --git a/packages/svelte/types/index.d.ts b/packages/svelte/types/index.d.ts
index aa01568463..c7f132bb00 100644
--- a/packages/svelte/types/index.d.ts
+++ b/packages/svelte/types/index.d.ts
@@ -756,6 +756,11 @@ declare module 'svelte/compiler' {
 		expression: Expression | ((id: Identifier) => Expression) | null;
 		/** If this is set, all mutations should use this expression */
 		mutation: ((assignment: AssignmentExpression, context: Context<any, any>) => Expression) | null;
+		/** Additional metadata, varies per binding type */
+		metadata: {
+			/** `true` if is (inside) a rest parameter */
+			inside_rest?: boolean;
+		} | null;
 	}
 	interface BaseNode_1 {
 		type: string;
@@ -1020,6 +1025,10 @@ declare module 'svelte/compiler' {
 		constructor(root: ScopeRoot, parent: Scope | null, porous: boolean);
 		
 		root: ScopeRoot;
+		/**
+		 * The immediate parent scope
+		 * */
+		parent: Scope | null;
 		/**
 		 * A map of every identifier declared by this scope, and all the
 		 * identifiers that reference it