validate_element() — svelte Function Reference

Source Code

packages/svelte/src/compiler/phases/2-analyze/visitors/shared/element.js lines 29–155

export function validate_element(node, context) {
	let has_animate_directive = false;

	/** @type {AST.TransitionDirective | null} */
	let in_transition = null;

	/** @type {AST.TransitionDirective | null} */
	let out_transition = null;

	for (const attribute of node.attributes) {
		if (attribute.type === 'Attribute') {
			const is_expression = is_expression_attribute(attribute);

			if (context.state.analysis.runes) {
				validate_attribute(attribute, node);

				if (is_expression) {
					const expression = get_attribute_expression(attribute);
					if (expression.type === 'SequenceExpression') {
						let i = /** @type {number} */ (expression.start);
						while (--i > 0) {
							const char = context.state.analysis.source[i];
							if (char === '(') break; // parenthesized sequence expressions are ok
							if (char === '{') e.attribute_invalid_sequence_expression(expression);
						}
					}
				}
			}

			if (regex_illegal_attribute_character.test(attribute.name)) {
				e.attribute_invalid_name(attribute, attribute.name);
			}

			if (attribute.name.startsWith('on') && attribute.name.length > 2) {
				if (!is_expression) {
					e.attribute_invalid_event_handler(attribute);
				}

				const value = get_attribute_expression(attribute);
				if (
					value.type === 'Identifier' &&
					value.name === attribute.name &&
					!context.state.scope.get(value.name)
				) {
					w.attribute_global_event_reference(attribute, attribute.name);
				}
			}

			if (attribute.name === 'slot') {
				/** @type {AST.RegularElement | AST.SvelteElement | AST.Component | AST.SvelteComponent | AST.SvelteSelf | undefined} */
				validate_slot_attribute(context, attribute);
			}

			if (attribute.name === 'is') {
				w.attribute_avoid_is(attribute);
			}

			const correct_name = react_attributes.get(attribute.name);
			if (correct_name) {
				w.attribute_invalid_property_name(attribute, attribute.name, correct_name);
			}

			validate_attribute_name(attribute);
		} else if (attribute.type === 'AnimateDirective') {
			const parent = context.path.at(-2);
			if (parent?.type !== 'EachBlock') {
				e.animation_invalid_placement(attribute);
			} else if (!parent.key) {
				e.animation_missing_key(attribute);
			} else if (
				parent.body.nodes.filter(
					(n) =>
						n.type !== 'Comment' &&
						n.type !== 'ConstTag' &&
						(n.type !== 'Text' || n.data.trim() !== '')
				).length > 1
			) {
				e.animation_invalid_placement(attribute);
			}

			if (has_animate_directive) {