From fc30c29a1950568cbba57fbd9429474b7df62988 Mon Sep 17 00:00:00 2001
From: Dmitry Gozman <dgozman@gmail.com>
Date: Sat, 19 Dec 2020 12:21:20 -0800
Subject: [PATCH] test: add a test for custom engine that does not respect root
 (#4777)

---
 test/selectors-register.spec.ts | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/test/selectors-register.spec.ts b/test/selectors-register.spec.ts
index 168ae483e3..88640a8dc2 100644
--- a/test/selectors-register.spec.ts
+++ b/test/selectors-register.spec.ts
@@ -123,3 +123,21 @@ it('should handle errors', async ({playwright, page}) => {
   error = await playwright.selectors.register('css', createDummySelector).catch(e => e);
   expect(error.message).toBe('"css" is a predefined selector engine');
 });
+
+it('should not rely on engines working from the root', async ({ playwright, page }) => {
+  const createValueEngine = () => ({
+    create(root, target) {
+      return undefined;
+    },
+    query(root, selector) {
+      return root && root.value.includes(selector) ? root : undefined;
+    },
+    queryAll(root, selector) {
+      return root && root.value.includes(selector) ? [root] : [];
+    },
+  });
+
+  await playwright.selectors.register('__value', createValueEngine);
+  await page.setContent(`<input id=input1 value=value1><input id=input2 value=value2>`);
+  expect(await page.$eval('input >> __value=value2', e => e.id)).toBe('input2');
+});