add test

packages/svelte/src/compiler/phases/1-parse/utils/html.js

@@ -122,7 +122,14 @@ function validate_code(code) {
 // based on http://developers.whatwg.org/syntax.html#syntax-tag-omission
 
 // while `input` is also an interactive element, it is never moved by the browser, so we don't need to check for it
-export const interactive_elements = new Set(['a', 'button', 'iframe', 'embed', 'select', 'textarea']);
+export const interactive_elements = new Set([
+	'a',
+	'button',
+	'iframe',
+	'embed',
+	'select',
+	'textarea'
+]);
 
 /** @type {Record<string, Set<string>>} */
 const disallowed_contents = {

packages/svelte/tests/validator/samples/invalid-node-placement/errors.json

@@ -0,0 +1,14 @@
+[
+	{
+		"code": "invalid-node-placement",
+		"message": "<a> is invalid inside <a>",
+		"start": {
+			"line": 4,
+			"column": 6
+		},
+		"end": {
+			"line": 4,
+			"column": 34
+		}
+	}
+]

packages/svelte/tests/validator/samples/invalid-node-placement/input.svelte

@@ -0,0 +1,7 @@
+<div>
+	<a href="/foo">
+		<div>
+			<p><a href="/foo">{`hello`}</a></p>
+		</div>
+	</a>
+</div>