[utils] `js_to_json`: Make function less fatal (#12715)

Authored by: seproDev

test/test_utils.py

@@ -1260,6 +1260,7 @@ class TestUtil(unittest.TestCase):
     def test_js_to_json_malformed(self):
         self.assertEqual(js_to_json('42a1'), '42"a1"')
         self.assertEqual(js_to_json('42a-1'), '42"a"-1')
+        self.assertEqual(js_to_json('{a: `${e("")}`}'), '{"a": "\\"e\\"(\\"\\")"}')
 
     def test_js_to_json_template_literal(self):
         self.assertEqual(js_to_json('`Hello ${name}`', {'name': '"world"'}), '"Hello world"')

yt_dlp/utils/_utils.py

@@ -2767,7 +2767,8 @@ def js_to_json(code, vars={}, *, strict=False):
     def template_substitute(match):
         evaluated = js_to_json(match.group(1), vars, strict=strict)
         if evaluated[0] == '"':
-            return json.loads(evaluated)
+            with contextlib.suppress(json.JSONDecodeError):
+                return json.loads(evaluated)
         return evaluated
 
     def fix_kv(m):