fix slot attribute validation

src/generators/nodes/Slot.ts

@@ -136,16 +136,16 @@ export default class Slot extends Element {
 
 	getStaticAttributeValue(name: string) {
 		const attribute = this.attributes.find(
-			(attr: Node) => attr.name.toLowerCase() === name
+			attr => attr.name.toLowerCase() === name
 		);
 
 		if (!attribute) return null;
 
-		if (attribute.value === true) return true;
-		if (attribute.value.length === 0) return '';
+		if (attribute.isTrue) return true;
+		if (attribute.chunks.length === 0) return '';
 
-		if (attribute.value.length === 1 && attribute.value[0].type === 'Text') {
-			return attribute.value[0].data;
+		if (attribute.chunks.length === 1 && attribute.chunks[0].type === 'Text') {
+			return attribute.chunks[0].data;
 		}
 
 		return null;

src/validate/html/validateElement.ts

@@ -295,9 +295,11 @@ function checkSlotAttribute(validator: Validator, node: Node, attribute: Node, s
 	let i = stack.length;
 	while (i--) {
 		const parent = stack[i];
-		if (parent.type === 'Element') {
+
+		if (parent.type === 'Component') {
 			// if we're inside a component or a custom element, gravy
 			if (parent.name === 'svelte:self' || parent.name === 'svelte:component' || validator.components.has(parent.name)) return;
+		} else if (parent.type === 'Element') {
 			if (/-/.test(parent.name)) return;
 		}