chore: ignore test directories left over from other branches (#10525)

* chore: ignore test directories left over from other branches

* tighten up

* one comment will do

---------

Co-authored-by: Rich Harris <rich.harris@vercel.com>

packages/svelte/tests/suite.ts

@@ -67,6 +67,10 @@ export function suite_with_variants<Test extends BaseTest, Variants extends stri
 	};
 }
 
+// If a directory only contains these children, it's a sign that it's leftover
+// from a different branch, and we can skip the test
+const ignored = ['_output', '_actual.json'];
+
 async function for_each_dir<Test extends BaseTest>(
 	cwd: string,
 	samples_dir = 'samples',
@@ -76,13 +80,14 @@ async function for_each_dir<Test extends BaseTest>(
 	let created_test = false;
 
 	for (const dir of fs.readdirSync(`${cwd}/${samples_dir}`)) {
-		if (dir[0] === '.') continue;
+		if (dir[0] === '.' || !filter.test(dir)) continue;
 
-		const file = `${cwd}/${samples_dir}/${dir}/_config.js`;
-		if (!filter.test(dir)) {
+		if (fs.readdirSync(`${cwd}/${samples_dir}/${dir}`).every((file) => ignored.includes(file))) {
 			continue;
 		}
 
+		const file = `${cwd}/${samples_dir}/${dir}/_config.js`;
+
 		created_test = true;
 		const config = (fs.existsSync(file) ? (await import(file)).default : {}) as Test;