read_options() — svelte Function Reference

Source Code

packages/svelte/src/compiler/phases/1-parse/read/options.js lines 10–197

export default function read_options(node) {
	/** @type {AST.SvelteOptions} */
	const component_options = {
		start: node.start,
		end: node.end,
		// @ts-ignore
		attributes: node.attributes
	};

	if (!node) {
		return component_options;
	}

	for (const attribute of node.attributes) {
		if (attribute.type !== 'Attribute') {
			e.svelte_options_invalid_attribute(attribute);
		}

		const { name } = attribute;

		switch (name) {
			case 'runes': {
				component_options.runes = get_boolean_value(attribute);
				break;
			}
			case 'tag': {
				e.svelte_options_deprecated_tag(attribute);
				break; // eslint doesn't know this is unnecessary
			}
			case 'customElement': {
				/** @type {AST.SvelteOptions['customElement']} */
				const ce = {};
				const { value: v } = attribute;
				const value = v === true || Array.isArray(v) ? v : [v];

				if (value === true) {
					e.svelte_options_invalid_customelement(attribute);
				} else if (value[0].type === 'Text') {
					const tag = get_static_value(attribute);
					validate_tag(attribute, tag);
					ce.tag = tag;
					component_options.customElement = ce;
					break;
				} else if (value[0].expression.type !== 'ObjectExpression') {
					// Before Svelte 4 it was necessary to explicitly set customElement to null or else you'd get a warning.
					// This is no longer necessary, but for backwards compat just skip in this case now.
					if (value[0].expression.type === 'Literal' && value[0].expression.value === null) {
						break;
					}
					e.svelte_options_invalid_customelement(attribute);
				}

				/** @type {Array<[string, any]>} */
				const properties = [];
				for (const property of value[0].expression.properties) {
					if (
						property.type !== 'Property' ||
						property.computed ||
						property.key.type !== 'Identifier'
					) {
						e.svelte_options_invalid_customelement(attribute);
					}
					properties.push([property.key.name, property.value]);
				}

				const tag = properties.find(([name]) => name === 'tag');
				if (tag) {
					const tag_value = tag[1]?.value;
					validate_tag(tag, tag_value);
					ce.tag = tag_value;
				}

				const props = properties.find(([name]) => name === 'props')?.[1];
				if (props) {
					if (props.type !== 'ObjectExpression') {
						e.svelte_options_invalid_customelement_props(attribute);
					}
					ce.props = {};
					for (const property of /** @type {ObjectExpression} */ (props).properties) {
						if (
							property.type !== 'Property' ||