svelte/packages/svelte/src/utils.js

const regex_return_characters = /\r/g;

/**
 * @param {string} str
 * @returns {string}
 */
export function hash(str) {
	str = str.replace(regex_return_characters, '');
	let hash = 5381;
	let i = str.length;

	while (i--) hash = ((hash << 5) - hash) ^ str.charCodeAt(i);
	return (hash >>> 0).toString(36);
}

const VOID_ELEMENT_NAMES = [
	'area',
	'base',
	'br',
	'col',
	'command',
	'embed',
	'hr',
	'img',
	'input',
	'keygen',
	'link',
	'meta',
	'param',
	'source',
	'track',
	'wbr'
];

/**
 * Returns `true` if `name` is of a void element
 * @param {string} name
 */
export function is_void(name) {
	return VOID_ELEMENT_NAMES.includes(name) || name.toLowerCase() === '!doctype';
}

const RESERVED_WORDS = [
	'arguments',
	'await',
	'break',
	'case',
	'catch',
	'class',
	'const',
	'continue',
	'debugger',
	'default',
	'delete',
	'do',
	'else',
	'enum',
	'eval',
	'export',
	'extends',
	'false',
	'finally',
	'for',
	'function',
	'if',
	'implements',
	'import',
	'in',
	'instanceof',
	'interface',
	'let',
	'new',
	'null',
	'package',
	'private',
	'protected',
	'public',
	'return',
	'static',
	'super',
	'switch',
	'this',
	'throw',
	'true',
	'try',
	'typeof',
	'var',
	'void',
	'while',
	'with',
	'yield'
];

/**
 * Returns `true` if `word` is a reserved JavaScript keyword
 * @param {string} word
 */
export function is_reserved(word) {
	return RESERVED_WORDS.includes(word);
}

/**
 * @param {string} name
 */
export function is_capture_event(name) {
	return name.endsWith('capture') && name !== 'gotpointercapture' && name !== 'lostpointercapture';
}

/** List of Element events that will be delegated */
const DELEGATED_EVENTS = [
	'beforeinput',
	'click',
	'change',
	'dblclick',
	'contextmenu',
	'focusin',
	'focusout',
	'input',
	'keydown',
	'keyup',
	'mousedown',
	'mousemove',
	'mouseout',
	'mouseover',
	'mouseup',
	'pointerdown',
	'pointermove',
	'pointerout',
	'pointerover',
	'pointerup',
	'touchend',
	'touchmove',
	'touchstart'
];

/**
 * Returns `true` if `event_name` is a delegated event
 * @param {string} event_name
 */
export function is_delegated(event_name) {
	return DELEGATED_EVENTS.includes(event_name);
}

/**
 * Attributes that are boolean, i.e. they are present or not present.
 */
const DOM_BOOLEAN_ATTRIBUTES = [
	'allowfullscreen',
	'async',
	'autofocus',
	'autoplay',
	'checked',
	'controls',
	'default',
	'disabled',
	'formnovalidate',
	'hidden',
	'indeterminate',
	'inert',
	'ismap',
	'loop',
	'multiple',
	'muted',
	'nomodule',
	'novalidate',
	'open',
	'playsinline',
	'readonly',
	'required',
	'reversed',
	'seamless',
	'selected',
	'webkitdirectory'
];

/**
 * Returns `true` if `name` is a boolean attribute
 * @param {string} name
 */
export function is_boolean_attribute(name) {
	return DOM_BOOLEAN_ATTRIBUTES.includes(name);
}

/**
 * @type {Record<string, string>}
 * List of attribute names that should be aliased to their property names
 * because they behave differently between setting them as an attribute and
 * setting them as a property.
 */
const ATTRIBUTE_ALIASES = {
	// no `class: 'className'` because we handle that separately
	formnovalidate: 'formNoValidate',
	ismap: 'isMap',
	nomodule: 'noModule',
	playsinline: 'playsInline',
	readonly: 'readOnly',
	defaultvalue: 'defaultValue',
	defaultchecked: 'defaultChecked',
	srcobject: 'srcObject'
};

/**
 * @param {string} name
 */
export function normalize_attribute(name) {
	name = name.toLowerCase();
	return ATTRIBUTE_ALIASES[name] ?? name;
}

const DOM_PROPERTIES = [
	...DOM_BOOLEAN_ATTRIBUTES,
	'formNoValidate',
	'isMap',
	'noModule',
	'playsInline',
	'readOnly',
	'value',
	'volume',
	'defaultValue',
	'defaultChecked',
	'srcObject'
];

/**
 * @param {string} name
 */
export function is_dom_property(name) {
	return DOM_PROPERTIES.includes(name);
}

const NON_STATIC_PROPERTIES = ['autofocus', 'muted', 'defaultValue', 'defaultChecked'];

/**
 * Returns `true` if the given attribute cannot be set through the template
 * string, i.e. needs some kind of JavaScript handling to work.
 * @param {string} name
 */
export function cannot_be_set_statically(name) {
	return NON_STATIC_PROPERTIES.includes(name);
}

/**
 * Subset of delegated events which should be passive by default.
 * These two are already passive via browser defaults on window, document and body.
 * But since
 * - we're delegating them
 * - they happen often
 * - they apply to mobile which is generally less performant
 * we're marking them as passive by default for other elements, too.
 */
const PASSIVE_EVENTS = ['touchstart', 'touchmove'];

/**
 * Returns `true` if `name` is a passive event
 * @param {string} name
 */
export function is_passive_event(name) {
	return PASSIVE_EVENTS.includes(name);
}

const CONTENT_EDITABLE_BINDINGS = ['textContent', 'innerHTML', 'innerText'];

/** @param {string} name */
export function is_content_editable_binding(name) {
	return CONTENT_EDITABLE_BINDINGS.includes(name);
}

const LOAD_ERROR_ELEMENTS = [
	'body',
	'embed',
	'iframe',
	'img',
	'link',
	'object',
	'script',
	'style',
	'track'
];

/**
 * Returns `true` if the element emits `load` and `error` events
 * @param {string} name
 */
export function is_load_error_element(name) {
	return LOAD_ERROR_ELEMENTS.includes(name);
}

const SVG_ELEMENTS = [
	'altGlyph',
	'altGlyphDef',
	'altGlyphItem',
	'animate',
	'animateColor',
	'animateMotion',
	'animateTransform',
	'circle',
	'clipPath',
	'color-profile',
	'cursor',
	'defs',
	'desc',
	'discard',
	'ellipse',
	'feBlend',
	'feColorMatrix',
	'feComponentTransfer',
	'feComposite',
	'feConvolveMatrix',
	'feDiffuseLighting',
	'feDisplacementMap',
	'feDistantLight',
	'feDropShadow',
	'feFlood',
	'feFuncA',
	'feFuncB',
	'feFuncG',
	'feFuncR',
	'feGaussianBlur',
	'feImage',
	'feMerge',
	'feMergeNode',
	'feMorphology',
	'feOffset',
	'fePointLight',
	'feSpecularLighting',
	'feSpotLight',
	'feTile',
	'feTurbulence',
	'filter',
	'font',
	'font-face',
	'font-face-format',
	'font-face-name',
	'font-face-src',
	'font-face-uri',
	'foreignObject',
	'g',
	'glyph',
	'glyphRef',
	'hatch',
	'hatchpath',
	'hkern',
	'image',
	'line',
	'linearGradient',
	'marker',
	'mask',
	'mesh',
	'meshgradient',
	'meshpatch',
	'meshrow',
	'metadata',
	'missing-glyph',
	'mpath',
	'path',
	'pattern',
	'polygon',
	'polyline',
	'radialGradient',
	'rect',
	'set',
	'solidcolor',
	'stop',
	'svg',
	'switch',
	'symbol',
	'text',
	'textPath',
	'tref',
	'tspan',
	'unknown',
	'use',
	'view',
	'vkern'
];

/** @param {string} name */
export function is_svg(name) {
	return SVG_ELEMENTS.includes(name);
}

const MATHML_ELEMENTS = [
	'annotation',
	'annotation-xml',
	'maction',
	'math',
	'merror',
	'mfrac',
	'mi',
	'mmultiscripts',
	'mn',
	'mo',
	'mover',
	'mpadded',
	'mphantom',
	'mprescripts',
	'mroot',
	'mrow',
	'ms',
	'mspace',
	'msqrt',
	'mstyle',
	'msub',
	'msubsup',
	'msup',
	'mtable',
	'mtd',
	'mtext',
	'mtr',
	'munder',
	'munderover',
	'semantics'
];

/** @param {string} name */
export function is_mathml(name) {
	return MATHML_ELEMENTS.includes(name);
}

const RUNES = /** @type {const} */ ([
	'$state',
	'$state.raw',
	'$state.snapshot',
	'$props',
	'$bindable',
	'$derived',
	'$derived.by',
	'$effect',
	'$effect.pre',
	'$effect.tracking',
	'$effect.root',
	'$inspect',
	'$inspect().with',
	'$inspect.trace',
	'$host'
]);

/**
 * @param {string} name
 * @returns {name is RUNES[number]}
 */
export function is_rune(name) {
	return RUNES.includes(/** @type {RUNES[number]} */ (name));
}

/** List of elements that require raw contents and should not have SSR comments put in them */
const RAW_TEXT_ELEMENTS = /** @type {const} */ (['textarea', 'script', 'style', 'title']);

/** @param {string} name */
export function is_raw_text_element(name) {
	return RAW_TEXT_ELEMENTS.includes(/** @type {RAW_TEXT_ELEMENTS[number]} */ (name));
}

/**
 * Prevent devtools trying to make `location` a clickable link by inserting a zero-width space
 * @param {string | undefined} location
 */
export function sanitize_location(location) {
	return location?.replace(/\//g, '/\u200b');
}