chore: remove references to node.parent (#14395)

* chore: remove references to node.parent

* types

* add ElementWithPath interface

* put path on analysis.elements instead of metadata

* Revert "put path on analysis.elements instead of metadata"

This reverts commit c0c7ab8.

* use node.metadata.path

* remove a node.parent usage

* another

* and another, albeit by replacing some bewildering code with some more bewildering code

* make loop idiomatic

* replace some more weirdo code

* simplify

Author: Rich-Harris

packages/svelte/src/compiler/phases/2-analyze/css/css-prune.js

@@ -260,12 +260,15 @@ function apply_combinator(combinator, relative_selector, parent_selectors, rule,
 	switch (name) {
 		case ' ':
 		case '>': {
-			let parent = /** @type {Compiler.TemplateNode | null} */ (element.parent);
-
 			let parent_matched = false;
 			let crossed_component_boundary = false;
 
-			while (parent) {
+			const path = element.metadata.path;
+			let i = path.length;
+
+			while (i--) {
+				const parent = path[i];
+
 				if (parent.type === 'Component' || parent.type === 'SvelteComponent') {
 					crossed_component_boundary = true;
 				}
@@ -289,8 +292,6 @@ function apply_combinator(combinator, relative_selector, parent_selectors, rule,
 
 					if (name === '>') return parent_matched;
 				}
-
-				parent = /** @type {Compiler.TemplateNode | null} */ (parent.parent);
 			}
 
 			return parent_matched || parent_selectors.every((selector) => is_global(selector, rule));
@@ -679,51 +680,50 @@ function relative_selector_might_apply_to_node(relative_selector, rule, element,
  * @param {boolean} include_self
  */
 function get_following_sibling_elements(element, include_self) {
-	/** @type {Compiler.AST.RegularElement | Compiler.AST.SvelteElement | Compiler.AST.Root | null} */
-	let parent = get_element_parent(element);
+	const path = element.metadata.path;
+	let i = path.length;
 
-	if (!parent) {
-		parent = element;
-		while (parent?.type !== 'Root') {
-			parent = /** @type {any} */ (parent).parent;
+	/** @type {Compiler.SvelteNode} */
+	let start = element;
+	let nodes = /** @type {Compiler.SvelteNode[]} */ (
+		/** @type {Compiler.AST.Fragment} */ (path[0]).nodes
+	);
+
+	// find the set of nodes to walk...
+	while (i--) {
+		const node = path[i];
+
+		if (node.type === 'RegularElement' || node.type === 'SvelteElement') {
+			nodes = node.fragment.nodes;
+			break;
+		}
+
+		if (node.type !== 'Fragment') {
+			start = node;
 		}
 	}
 
 	/** @type {Array<Compiler.AST.RegularElement | Compiler.AST.SvelteElement>} */
-	const sibling_elements = [];
-	let found_parent = false;
-
-	for (const el of parent.fragment.nodes) {
-		if (found_parent) {
-			walk(
-				el,
-				{},
-				{
-					RegularElement(node) {
-						sibling_elements.push(node);
-					},
-					SvelteElement(node) {
-						sibling_elements.push(node);
-					}
-				}
-			);
-		} else {
-			/** @type {any} */
-			let child = element;
-			while (child !== el && child !== parent) {
-				child = child.parent;
+	const siblings = [];
+
+	// ...then walk them, starting from the node after the one
+	// containing the element in question
+	for (const node of nodes.slice(nodes.indexOf(start) + 1)) {
+		walk(node, null, {
+			RegularElement(node) {
+				siblings.push(node);
+			},
+			SvelteElement(node) {
+				siblings.push(node);
 			}
-			if (child === el) {
-				found_parent = true;
-			}
-		}
+		});
 	}
 
 	if (include_self) {
-		sibling_elements.push(element);
+		siblings.push(element);
 	}
 
-	return sibling_elements;
+	return siblings;
 }
 
 /**
@@ -867,15 +867,18 @@ function unquote(str) {
  * @returns {Compiler.AST.RegularElement | Compiler.AST.SvelteElement | null}
  */
 function get_element_parent(node) {
-	/** @type {Compiler.SvelteNode | null} */
-	let parent = node;
-	while (
-		// @ts-expect-error TODO figure out a more elegant solution
-		(parent = parent.parent) &&
-		parent.type !== 'RegularElement' &&
-		parent.type !== 'SvelteElement'
-	);
-	return parent ?? null;
+	let path = node.metadata.path;
+	let i = path.length;
+
+	while (i--) {
+		const parent = path[i];
+
+		if (parent.type === 'RegularElement' || parent.type === 'SvelteElement') {
+			return parent;
+		}
+	}
+
+	return null;
 }
 
 /**
@@ -920,7 +923,7 @@ function find_previous_sibling(node) {
 	while (current_node?.type === 'SlotElement') {
 		const slot_children = current_node.fragment.nodes;
 		if (slot_children.length > 0) {
-			current_node = slot_children.slice(-1)[0];
+			current_node = slot_children[slot_children.length - 1];
 		} else {
 			break;
 		}
@@ -1118,8 +1121,12 @@ function mark_as_probably(result) {
 function loop_child(children, adjacent_only) {
 	/** @type {Map<Compiler.AST.RegularElement, NodeExistsValue>} */
 	const result = new Map();
-	for (let i = children.length - 1; i >= 0; i--) {
+
+	let i = children.length;
+
+	while (i--) {
 		const child = children[i];
+
 		if (child.type === 'RegularElement') {
 			result.set(child, NODE_DEFINITELY_EXISTS);
 			if (adjacent_only) {
@@ -1137,5 +1144,6 @@ function loop_child(children, adjacent_only) {
 			}
 		}
 	}
+
 	return result;
 }

packages/svelte/src/compiler/phases/2-analyze/index.js

@@ -709,8 +709,8 @@ export function analyze_component(root, source, options) {
 		analyze_css(analysis.css.ast, analysis);
 
 		// mark nodes as scoped/unused/empty etc
-		for (const element of analysis.elements) {
-			prune(analysis.css.ast, element);
+		for (const node of analysis.elements) {
+			prune(analysis.css.ast, node);
 		}
 
 		const { comment } = analysis.css.ast.content;
@@ -724,18 +724,18 @@ export function analyze_component(root, source, options) {
 			warn_unused(analysis.css.ast);
 		}
 
-		outer: for (const element of analysis.elements) {
-			if (element.type === 'RenderTag') continue;
+		outer: for (const node of analysis.elements) {
+			if (node.type === 'RenderTag') continue;
 
-			if (element.metadata.scoped) {
+			if (node.metadata.scoped) {
 				// Dynamic elements in dom mode always use spread for attributes and therefore shouldn't have a class attribute added to them
 				// TODO this happens during the analysis phase, which shouldn't know anything about client vs server
-				if (element.type === 'SvelteElement' && options.generate === 'client') continue;
+				if (node.type === 'SvelteElement' && options.generate === 'client') continue;
 
 				/** @type {AST.Attribute | undefined} */
 				let class_attribute = undefined;
 
-				for (const attribute of element.attributes) {
+				for (const attribute of node.attributes) {
 					if (attribute.type === 'SpreadAttribute') {
 						// The spread method appends the hash to the end of the class attribute on its own
 						continue outer;
@@ -768,7 +768,7 @@ export function analyze_component(root, source, options) {
 						}
 					}
 				} else {
-					element.attributes.push(
+					node.attributes.push(
 						create_attribute('class', -1, -1, [
 							{
 								type: 'Text',
@@ -780,8 +780,8 @@ export function analyze_component(root, source, options) {
 							}
 						])
 					);
-					if (is_custom_element_node(element) && element.attributes.length === 1) {
-						mark_subtree_dynamic(element.metadata.path);
+					if (is_custom_element_node(node) && node.attributes.length === 1) {
+						mark_subtree_dynamic(node.metadata.path);
 					}
 				}
 			}

packages/svelte/src/compiler/phases/2-analyze/visitors/ExpressionTag.js

@@ -9,7 +9,9 @@ import { mark_subtree_dynamic } from './shared/fragment.js';
  * @param {Context} context
  */
 export function ExpressionTag(node, context) {
-	if (node.parent && context.state.parent_element) {
+	const in_attribute = context.path.at(-1)?.type === 'Attribute';
+
+	if (!in_attribute && context.state.parent_element) {
 		if (!is_tag_valid_with_parent('#text', context.state.parent_element)) {
 			e.node_invalid_placement(node, '`{expression}`', context.state.parent_element);
 		}

packages/svelte/src/compiler/phases/2-analyze/visitors/RegularElement.js

@@ -19,11 +19,9 @@ import { mark_subtree_dynamic } from './shared/fragment.js';
  */
 export function RegularElement(node, context) {
 	validate_element(node, context);
-
-	check_element(node, context.state);
+	check_element(node, context);
 
 	node.metadata.path = [...context.path];
-
 	context.state.analysis.elements.push(node);
 
 	// Special case: Move the children of <textarea> into a value attribute if they are dynamic

packages/svelte/src/compiler/phases/2-analyze/visitors/RenderTag.js

@@ -12,6 +12,7 @@ import { mark_subtree_dynamic } from './shared/fragment.js';
 export function RenderTag(node, context) {
 	validate_opening_tag(node, context.state, '@');
 
+	node.metadata.path = [...context.path];
 	context.state.analysis.elements.push(node);
 
 	const callee = unwrap_optional(node.expression).callee;

packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteElement.js

@@ -12,9 +12,9 @@ import { mark_subtree_dynamic } from './shared/fragment.js';
  */
 export function SvelteElement(node, context) {
 	validate_element(node, context);
+	check_element(node, context);
 
-	check_element(node, context.state);
-
+	node.metadata.path = [...context.path];
 	context.state.analysis.elements.push(node);
 
 	const xmlns = /** @type {AST.Attribute & { value: [AST.Text] } | undefined} */ (

packages/svelte/src/compiler/phases/2-analyze/visitors/Text.js

@@ -9,7 +9,9 @@ import * as e from '../../../errors.js';
  * @param {Context} context
  */
 export function Text(node, context) {
-	if (node.parent && context.state.parent_element && regex_not_whitespace.test(node.data)) {
+	const in_attribute = context.path.at(-1)?.type === 'Attribute';
+
+	if (!in_attribute && context.state.parent_element && regex_not_whitespace.test(node.data)) {
 		if (!is_tag_valid_with_parent('#text', context.state.parent_element)) {
 			e.node_invalid_placement(node, 'Text node', context.state.parent_element);
 		}

packages/svelte/src/compiler/phases/2-analyze/visitors/shared/a11y.js

@@ -1,4 +1,4 @@
-/** @import { AnalysisState } from '../../types.js' */
+/** @import { Context } from '../../types.js' */
 /** @import { AST, SvelteNode, TemplateNode } from '#compiler' */
 /** @import { ARIARoleDefinitionKey, ARIARoleRelationConcept, ARIAProperty, ARIAPropertyDefinition, ARIARoleDefinition } from 'aria-query' */
 import { roles as roles_map, aria, elementRoles } from 'aria-query';
@@ -582,16 +582,17 @@ function get_implicit_role(name, attribute_map) {
 const invisible_elements = ['meta', 'html', 'script', 'style'];
 
 /**
- * @param {SvelteNode | null} parent
+ * @param {SvelteNode[]} path
  * @param {string[]} elements
  */
-function is_parent(parent, elements) {
-	while (parent) {
+function is_parent(path, elements) {
+	let i = path.length;
+	while (i--) {
+		const parent = path[i];
 		if (parent.type === 'SvelteElement') return true; // unknown, play it safe, so we don't warn
 		if (parent.type === 'RegularElement') {
 			return elements.includes(parent.name);
 		}
-		parent = /** @type {TemplateNode} */ (parent).parent;
 	}
 	return false;
 }
@@ -683,9 +684,9 @@ function get_static_text_value(attribute) {
 
 /**
  * @param {AST.RegularElement | AST.SvelteElement} node
- * @param {AnalysisState} state
+ * @param {Context} context
  */
-export function check_element(node, state) {
+export function check_element(node, context) {
 	/** @type {Map<string, AST.Attribute>} */
 	const attribute_map = new Map();
 
@@ -792,7 +793,7 @@ export function check_element(node, state) {
 					}
 
 					// Footers and headers are special cases, and should not have redundant roles unless they are the children of sections or articles.
-					const is_parent_section_or_article = is_parent(node.parent, ['section', 'article']);
+					const is_parent_section_or_article = is_parent(context.path, ['section', 'article']);
 					if (!is_parent_section_or_article) {
 						const has_nested_redundant_role =
 							current_role === a11y_nested_implicit_semantics.get(node.name);
@@ -1114,7 +1115,7 @@ export function check_element(node, state) {
 	}
 
 	if (node.name === 'figcaption') {
-		if (!is_parent(node.parent, ['figure'])) {
+		if (!is_parent(context.path, ['figure'])) {
 			w.a11y_figcaption_parent(node);
 		}
 	}

packages/svelte/src/compiler/types/template.d.ts

@@ -167,6 +167,7 @@ export namespace AST {
 		metadata: {
 			dynamic: boolean;
 			args_with_call_expression: Set<number>;
+			path: SvelteNode[];
 		};
 	}
 
@@ -344,6 +345,7 @@ export namespace AST {
 			 */
 			mathml: boolean;
 			scoped: boolean;
+			path: SvelteNode[];
 		};
 	}