From 4db4ee53305dbf1f29d2f6ddadb5201a4854c590 Mon Sep 17 00:00:00 2001
From: 7nik <kfiiranet@gmail.com>
Date: Mon, 23 Jun 2025 13:18:14 +0300
Subject: [PATCH] chore: rid of nodeType magic numbers (#16208)

* chore: rid of nodeType magic numbers

* lint

---------

Co-authored-by: 7nik <kifiranet@gmail.com>
---
 .../svelte/src/internal/client/constants.js   |  5 +++++
 .../src/internal/client/dev/elements.js       |  7 ++++---
 .../src/internal/client/dom/blocks/each.js    |  4 ++--
 .../src/internal/client/dom/blocks/html.js    |  6 +++++-
 .../src/internal/client/dom/blocks/snippet.js |  4 ++--
 .../client/dom/blocks/svelte-element.js       |  4 ++--
 .../internal/client/dom/blocks/svelte-head.js |  5 +++--
 .../src/internal/client/dom/hydration.js      |  5 +++--
 .../src/internal/client/dom/operations.js     |  9 ++++-----
 .../src/internal/client/dom/template.js       |  7 ++++---
 packages/svelte/src/internal/client/render.js |  5 +++--
 packages/svelte/tests/html_equal.js           | 19 ++++++++++---------
 .../svelte/tests/runtime-browser/assert.js    |  5 ++++-
 .../samples/template/_config.js               |  3 ++-
 14 files changed, 53 insertions(+), 35 deletions(-)

diff --git a/packages/svelte/src/internal/client/constants.js b/packages/svelte/src/internal/client/constants.js
index 98cef658bf..3ca915f98e 100644
--- a/packages/svelte/src/internal/client/constants.js
+++ b/packages/svelte/src/internal/client/constants.js
@@ -26,3 +26,8 @@ export const STATE_SYMBOL = Symbol('$state');
 export const LEGACY_PROPS = Symbol('legacy props');
 export const LOADING_ATTR_SYMBOL = Symbol('');
 export const PROXY_PATH_SYMBOL = Symbol('proxy path');
+
+export const ELEMENT_NODE = 1;
+export const TEXT_NODE = 3;
+export const COMMENT_NODE = 8;
+export const DOCUMENT_FRAGMENT_NODE = 11;
diff --git a/packages/svelte/src/internal/client/dev/elements.js b/packages/svelte/src/internal/client/dev/elements.js
index 62ac09d784..f70f893d1e 100644
--- a/packages/svelte/src/internal/client/dev/elements.js
+++ b/packages/svelte/src/internal/client/dev/elements.js
@@ -1,4 +1,5 @@
 /** @import { SourceLocation } from '#client' */
+import { COMMENT_NODE, DOCUMENT_FRAGMENT_NODE, ELEMENT_NODE } from '#client/constants';
 import { HYDRATION_END, HYDRATION_START, HYDRATION_START_ELSE } from '../../../constants.js';
 import { hydrating } from '../dom/hydration.js';
 
@@ -12,7 +13,7 @@ export function add_locations(fn, filename, locations) {
 	return (/** @type {any[]} */ ...args) => {
 		const dom = fn(...args);
 
-		var node = hydrating ? dom : dom.nodeType === 11 ? dom.firstChild : dom;
+		var node = hydrating ? dom : dom.nodeType === DOCUMENT_FRAGMENT_NODE ? dom.firstChild : dom;
 		assign_locations(node, filename, locations);
 
 		return dom;
@@ -45,13 +46,13 @@ function assign_locations(node, filename, locations) {
 	var depth = 0;
 
 	while (node && i < locations.length) {
-		if (hydrating && node.nodeType === 8) {
+		if (hydrating && node.nodeType === COMMENT_NODE) {
 			var comment = /** @type {Comment} */ (node);
 			if (comment.data === HYDRATION_START || comment.data === HYDRATION_START_ELSE) depth += 1;
 			else if (comment.data[0] === HYDRATION_END) depth -= 1;
 		}
 
-		if (depth === 0 && node.nodeType === 1) {
+		if (depth === 0 && node.nodeType === ELEMENT_NODE) {
 			assign_location(/** @type {Element} */ (node), filename, locations[i++]);
 		}
 
diff --git a/packages/svelte/src/internal/client/dom/blocks/each.js b/packages/svelte/src/internal/client/dom/blocks/each.js
index b638a6d2da..7b12be58e8 100644
--- a/packages/svelte/src/internal/client/dom/blocks/each.js
+++ b/packages/svelte/src/internal/client/dom/blocks/each.js
@@ -34,7 +34,7 @@ import {
 } from '../../reactivity/effects.js';
 import { source, mutable_source, internal_set } from '../../reactivity/sources.js';
 import { array_from, is_array } from '../../../shared/utils.js';
-import { INERT } from '#client/constants';
+import { COMMENT_NODE, INERT } from '#client/constants';
 import { queue_micro_task } from '../task.js';
 import { active_effect, get } from '../../runtime.js';
 import { DEV } from 'esm-env';
@@ -183,7 +183,7 @@ export function each(node, flags, get_collection, get_key, render_fn, fallback_f
 
 			for (var i = 0; i < length; i++) {
 				if (
-					hydrate_node.nodeType === 8 &&
+					hydrate_node.nodeType === COMMENT_NODE &&
 					/** @type {Comment} */ (hydrate_node).data === HYDRATION_END
 				) {
 					// The server rendered fewer items than expected,
diff --git a/packages/svelte/src/internal/client/dom/blocks/html.js b/packages/svelte/src/internal/client/dom/blocks/html.js
index 92c8243478..d7190abc66 100644
--- a/packages/svelte/src/internal/client/dom/blocks/html.js
+++ b/packages/svelte/src/internal/client/dom/blocks/html.js
@@ -10,6 +10,7 @@ import { DEV } from 'esm-env';
 import { dev_current_component_function } from '../../context.js';
 import { get_first_child, get_next_sibling } from '../operations.js';
 import { active_effect } from '../../runtime.js';
+import { COMMENT_NODE } from '#client/constants';
 
 /**
  * @param {Element} element
@@ -67,7 +68,10 @@ export function html(node, get_value, svg = false, mathml = false, skip_warning
 			var next = hydrate_next();
 			var last = next;
 
-			while (next !== null && (next.nodeType !== 8 || /** @type {Comment} */ (next).data !== '')) {
+			while (
+				next !== null &&
+				(next.nodeType !== COMMENT_NODE || /** @type {Comment} */ (next).data !== '')
+			) {
 				last = next;
 				next = /** @type {TemplateNode} */ (get_next_sibling(next));
 			}
diff --git a/packages/svelte/src/internal/client/dom/blocks/snippet.js b/packages/svelte/src/internal/client/dom/blocks/snippet.js
index c6dce26bfe..32d88d4c60 100644
--- a/packages/svelte/src/internal/client/dom/blocks/snippet.js
+++ b/packages/svelte/src/internal/client/dom/blocks/snippet.js
@@ -1,7 +1,7 @@
 /** @import { Snippet } from 'svelte' */
 /** @import { Effect, TemplateNode } from '#client' */
 /** @import { Getters } from '#shared' */
-import { EFFECT_TRANSPARENT } from '#client/constants';
+import { EFFECT_TRANSPARENT, ELEMENT_NODE } from '#client/constants';
 import { branch, block, destroy_effect, teardown } from '../../reactivity/effects.js';
 import {
 	dev_current_component_function,
@@ -102,7 +102,7 @@ export function createRawSnippet(fn) {
 			var fragment = create_fragment_from_html(html);
 			element = /** @type {Element} */ (get_first_child(fragment));
 
-			if (DEV && (get_next_sibling(element) !== null || element.nodeType !== 1)) {
+			if (DEV && (get_next_sibling(element) !== null || element.nodeType !== ELEMENT_NODE)) {
 				w.invalid_raw_snippet_render();
 			}
 
diff --git a/packages/svelte/src/internal/client/dom/blocks/svelte-element.js b/packages/svelte/src/internal/client/dom/blocks/svelte-element.js
index 43f669e844..ffa57b2d8b 100644
--- a/packages/svelte/src/internal/client/dom/blocks/svelte-element.js
+++ b/packages/svelte/src/internal/client/dom/blocks/svelte-element.js
@@ -20,7 +20,7 @@ import { current_each_item, set_current_each_item } from './each.js';
 import { active_effect } from '../../runtime.js';
 import { component_context } from '../../context.js';
 import { DEV } from 'esm-env';
-import { EFFECT_TRANSPARENT } from '#client/constants';
+import { EFFECT_TRANSPARENT, ELEMENT_NODE } from '#client/constants';
 import { assign_nodes } from '../template.js';
 import { is_raw_text_element } from '../../../../utils.js';
 
@@ -51,7 +51,7 @@ export function element(node, get_tag, is_svg, render_fn, get_namespace, locatio
 	/** @type {null | Element} */
 	var element = null;
 
-	if (hydrating && hydrate_node.nodeType === 1) {
+	if (hydrating && hydrate_node.nodeType === ELEMENT_NODE) {
 		element = /** @type {Element} */ (hydrate_node);
 		hydrate_next();
 	}
diff --git a/packages/svelte/src/internal/client/dom/blocks/svelte-head.js b/packages/svelte/src/internal/client/dom/blocks/svelte-head.js
index db2a0c4ef1..66d3371836 100644
--- a/packages/svelte/src/internal/client/dom/blocks/svelte-head.js
+++ b/packages/svelte/src/internal/client/dom/blocks/svelte-head.js
@@ -2,7 +2,7 @@
 import { hydrate_node, hydrating, set_hydrate_node, set_hydrating } from '../hydration.js';
 import { create_text, get_first_child, get_next_sibling } from '../operations.js';
 import { block } from '../../reactivity/effects.js';
-import { HEAD_EFFECT } from '#client/constants';
+import { COMMENT_NODE, HEAD_EFFECT } from '#client/constants';
 import { HYDRATION_START } from '../../../../constants.js';
 
 /**
@@ -37,7 +37,8 @@ export function head(render_fn) {
 
 		while (
 			head_anchor !== null &&
-			(head_anchor.nodeType !== 8 || /** @type {Comment} */ (head_anchor).data !== HYDRATION_START)
+			(head_anchor.nodeType !== COMMENT_NODE ||
+				/** @type {Comment} */ (head_anchor).data !== HYDRATION_START)
 		) {
 			head_anchor = /** @type {TemplateNode} */ (get_next_sibling(head_anchor));
 		}
diff --git a/packages/svelte/src/internal/client/dom/hydration.js b/packages/svelte/src/internal/client/dom/hydration.js
index ab3256da82..1f80b7922b 100644
--- a/packages/svelte/src/internal/client/dom/hydration.js
+++ b/packages/svelte/src/internal/client/dom/hydration.js
@@ -1,5 +1,6 @@
 /** @import { TemplateNode } from '#client' */
 
+import { COMMENT_NODE } from '#client/constants';
 import {
 	HYDRATION_END,
 	HYDRATION_ERROR,
@@ -87,7 +88,7 @@ export function remove_nodes() {
 	var node = hydrate_node;
 
 	while (true) {
-		if (node.nodeType === 8) {
+		if (node.nodeType === COMMENT_NODE) {
 			var data = /** @type {Comment} */ (node).data;
 
 			if (data === HYDRATION_END) {
@@ -109,7 +110,7 @@ export function remove_nodes() {
  * @param {TemplateNode} node
  */
 export function read_hydration_instruction(node) {
-	if (!node || node.nodeType !== 8) {
+	if (!node || node.nodeType !== COMMENT_NODE) {
 		w.hydration_mismatch();
 		throw HYDRATION_ERROR;
 	}
diff --git a/packages/svelte/src/internal/client/dom/operations.js b/packages/svelte/src/internal/client/dom/operations.js
index 97062f04e3..4b35f0802f 100644
--- a/packages/svelte/src/internal/client/dom/operations.js
+++ b/packages/svelte/src/internal/client/dom/operations.js
@@ -3,6 +3,7 @@ import { hydrate_node, hydrating, set_hydrate_node } from './hydration.js';
 import { DEV } from 'esm-env';
 import { init_array_prototype_warnings } from '../dev/equality.js';
 import { get_descriptor, is_extensible } from '../../shared/utils.js';
+import { TEXT_NODE } from '#client/constants';
 
 // export these for reference in the compiled code, making global name deduplication unnecessary
 /** @type {Window} */
@@ -113,7 +114,7 @@ export function child(node, is_text) {
 	// Child can be null if we have an element with a single child, like `<p>{text}</p>`, where `text` is empty
 	if (child === null) {
 		child = hydrate_node.appendChild(create_text());
-	} else if (is_text && child.nodeType !== 3) {
+	} else if (is_text && child.nodeType !== TEXT_NODE) {
 		var text = create_text();
 		child?.before(text);
 		set_hydrate_node(text);
@@ -143,7 +144,7 @@ export function first_child(fragment, is_text) {
 
 	// if an {expression} is empty during SSR, there might be no
 	// text node to hydrate — we must therefore create one
-	if (is_text && hydrate_node?.nodeType !== 3) {
+	if (is_text && hydrate_node?.nodeType !== TEXT_NODE) {
 		var text = create_text();
 
 		hydrate_node?.before(text);
@@ -174,11 +175,9 @@ export function sibling(node, count = 1, is_text = false) {
 		return next_sibling;
 	}
 
-	var type = next_sibling?.nodeType;
-
 	// if a sibling {expression} is empty during SSR, there might be no
 	// text node to hydrate — we must therefore create one
-	if (is_text && type !== 3) {
+	if (is_text && next_sibling?.nodeType !== TEXT_NODE) {
 		var text = create_text();
 		// If the next sibling is `null` and we're handling text then it's because
 		// the SSR content was empty for the text, so we need to generate a new text
diff --git a/packages/svelte/src/internal/client/dom/template.js b/packages/svelte/src/internal/client/dom/template.js
index 0b77ab1396..ebbf0039b2 100644
--- a/packages/svelte/src/internal/client/dom/template.js
+++ b/packages/svelte/src/internal/client/dom/template.js
@@ -20,6 +20,7 @@ import {
 	TEMPLATE_USE_MATHML,
 	TEMPLATE_USE_SVG
 } from '../../../constants.js';
+import { COMMENT_NODE, DOCUMENT_FRAGMENT_NODE, TEXT_NODE } from '#client/constants';
 
 /**
  * @param {TemplateNode} start
@@ -264,7 +265,7 @@ function run_scripts(node) {
 	// scripts were SSR'd, in which case they will run
 	if (hydrating) return node;
 
-	const is_fragment = node.nodeType === 11;
+	const is_fragment = node.nodeType === DOCUMENT_FRAGMENT_NODE;
 	const scripts =
 		/** @type {HTMLElement} */ (node).tagName === 'SCRIPT'
 			? [/** @type {HTMLScriptElement} */ (node)]
@@ -305,7 +306,7 @@ export function text(value = '') {
 
 	var node = hydrate_node;
 
-	if (node.nodeType !== 3) {
+	if (node.nodeType !== TEXT_NODE) {
 		// if an {expression} is empty during SSR, we need to insert an empty text node
 		node.before((node = create_text()));
 		set_hydrate_node(node);
@@ -360,7 +361,7 @@ export function props_id() {
 	if (
 		hydrating &&
 		hydrate_node &&
-		hydrate_node.nodeType === 8 &&
+		hydrate_node.nodeType === COMMENT_NODE &&
 		hydrate_node.textContent?.startsWith(`#`)
 	) {
 		const id = hydrate_node.textContent.substring(1);
diff --git a/packages/svelte/src/internal/client/render.js b/packages/svelte/src/internal/client/render.js
index 3256fe8274..ff6844453d 100644
--- a/packages/svelte/src/internal/client/render.js
+++ b/packages/svelte/src/internal/client/render.js
@@ -30,6 +30,7 @@ import * as w from './warnings.js';
 import * as e from './errors.js';
 import { assign_nodes } from './dom/template.js';
 import { is_passive_event } from '../../utils.js';
+import { COMMENT_NODE } from './constants.js';
 
 /**
  * This is normally true — block effects should run their intro transitions —
@@ -107,7 +108,7 @@ export function hydrate(component, options) {
 		var anchor = /** @type {TemplateNode} */ (get_first_child(target));
 		while (
 			anchor &&
-			(anchor.nodeType !== 8 || /** @type {Comment} */ (anchor).data !== HYDRATION_START)
+			(anchor.nodeType !== COMMENT_NODE || /** @type {Comment} */ (anchor).data !== HYDRATION_START)
 		) {
 			anchor = /** @type {TemplateNode} */ (get_next_sibling(anchor));
 		}
@@ -124,7 +125,7 @@ export function hydrate(component, options) {
 
 		if (
 			hydrate_node === null ||
-			hydrate_node.nodeType !== 8 ||
+			hydrate_node.nodeType !== COMMENT_NODE ||
 			/** @type {Comment} */ (hydrate_node).data !== HYDRATION_END
 		) {
 			w.hydration_mismatch();
diff --git a/packages/svelte/tests/html_equal.js b/packages/svelte/tests/html_equal.js
index 6948d8db32..b637e4d538 100644
--- a/packages/svelte/tests/html_equal.js
+++ b/packages/svelte/tests/html_equal.js
@@ -1,3 +1,4 @@
+import { COMMENT_NODE, ELEMENT_NODE, TEXT_NODE } from '#client/constants';
 import { assert } from 'vitest';
 
 /**
@@ -35,7 +36,7 @@ function clean_children(node, opts) {
 	});
 
 	for (let child of [...node.childNodes]) {
-		if (child.nodeType === 3) {
+		if (child.nodeType === TEXT_NODE) {
 			let text = /** @type {Text} */ (child);
 
 			if (
@@ -49,7 +50,7 @@ function clean_children(node, opts) {
 
 			text.data = text.data.replace(/[^\S]+/g, ' ');
 
-			if (previous && previous.nodeType === 3) {
+			if (previous && previous.nodeType === TEXT_NODE) {
 				const prev = /** @type {Text} */ (previous);
 
 				prev.data += text.data;
@@ -62,22 +63,22 @@ function clean_children(node, opts) {
 			}
 		}
 
-		if (child.nodeType === 8 && !opts.preserveComments) {
+		if (child.nodeType === COMMENT_NODE && !opts.preserveComments) {
 			// comment
 			child.remove();
 			continue;
 		}
 
 		// add newlines for better readability and potentially recurse into children
-		if (child.nodeType === 1 || child.nodeType === 8) {
-			if (previous?.nodeType === 3) {
+		if (child.nodeType === ELEMENT_NODE || child.nodeType === COMMENT_NODE) {
+			if (previous?.nodeType === TEXT_NODE) {
 				const prev = /** @type {Text} */ (previous);
 				prev.data = prev.data.replace(/^[^\S]+$/, '\n');
-			} else if (previous?.nodeType === 1 || previous?.nodeType === 8) {
+			} else if (previous?.nodeType === ELEMENT_NODE || previous?.nodeType === COMMENT_NODE) {
 				node.insertBefore(document.createTextNode('\n'), child);
 			}
 
-			if (child.nodeType === 1) {
+			if (child.nodeType === ELEMENT_NODE) {
 				has_element_children = true;
 				clean_children(/** @type {Element} */ (child), opts);
 			}
@@ -87,12 +88,12 @@ function clean_children(node, opts) {
 	}
 
 	// collapse whitespace
-	if (node.firstChild && node.firstChild.nodeType === 3) {
+	if (node.firstChild && node.firstChild.nodeType === TEXT_NODE) {
 		const text = /** @type {Text} */ (node.firstChild);
 		text.data = text.data.trimStart();
 	}
 
-	if (node.lastChild && node.lastChild.nodeType === 3) {
+	if (node.lastChild && node.lastChild.nodeType === TEXT_NODE) {
 		const text = /** @type {Text} */ (node.lastChild);
 		text.data = text.data.trimEnd();
 	}
diff --git a/packages/svelte/tests/runtime-browser/assert.js b/packages/svelte/tests/runtime-browser/assert.js
index fb460c722a..48bde01410 100644
--- a/packages/svelte/tests/runtime-browser/assert.js
+++ b/packages/svelte/tests/runtime-browser/assert.js
@@ -1,5 +1,8 @@
 /** @import { assert } from 'vitest' */
 /** @import { CompileOptions, Warning } from '#compiler' */
+
+import { ELEMENT_NODE } from '#client/constants';
+
 /**
  * @param {any} a
  * @param {any} b
@@ -102,7 +105,7 @@ function normalize_children(node) {
 	}
 
 	for (let child of [...node.childNodes]) {
-		if (child.nodeType === 1 /* Element */) {
+		if (child.nodeType === ELEMENT_NODE) {
 			normalize_children(child);
 		}
 	}
diff --git a/packages/svelte/tests/runtime-legacy/samples/template/_config.js b/packages/svelte/tests/runtime-legacy/samples/template/_config.js
index f827168542..7576b6fbb8 100644
--- a/packages/svelte/tests/runtime-legacy/samples/template/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/template/_config.js
@@ -1,3 +1,4 @@
+import { COMMENT_NODE } from '#client/constants';
 import { ok, test } from '../../test';
 
 export default test({
@@ -41,7 +42,7 @@ export default test({
 		// get all childNodes of template3 except comments
 		let childNodes = [];
 		for (const node of template3.content.childNodes) {
-			if (node.nodeType !== 8) {
+			if (node.nodeType !== COMMENT_NODE) {
 				childNodes.push(/** @type {Element} */ (node));
 			}
 		}