[utils] Improve and test js_to_json

2 files changed, 21 insertions, 22 deletions

diff --git a/youtube_dl/extractor/common.py b/youtube_dl/extractor/common.py
index f43a0a569..611cf95f1 100644
--- a/youtube_dl/extractor/common.py
+++ b/youtube_dl/extractor/common.py
@@ -334,7 +334,11 @@ class InfoExtractor(object):
         try:
             return json.loads(json_string)
         except ValueError as ve:
-            raise ExtractorError('Failed to download JSON', cause=ve)
+            errmsg = '%s: Failed to parse JSON ' % video_id
+            if fatal:
+                raise ExtractorError(errmsg, cause=ve)
+            else:
+                self.report_warning(errmsg + str(ve))
 
     def report_warning(self, msg, video_id=None):
         idstr = '' if video_id is None else '%s: ' % video_id
diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py
index 59851a8c0..f8dd9c72d 100644
--- a/youtube_dl/utils.py
+++ b/youtube_dl/utils.py
@@ -1580,29 +1580,24 @@ def strip_jsonp(code):
 
 def js_to_json(code):
     def fix_kv(m):
-        key = m.group(2)
-        if key.startswith("'"):
-            assert key.endswith("'")
-            assert '"' not in key
-            key = '"%s"' % key[1:-1]
-        elif not key.startswith('"'):
-            key = '"%s"' % key
-
-        value = m.group(4)
-        if value.startswith("'"):
-            assert value.endswith("'")
-            assert '"' not in value
-            value = '"%s"' % value[1:-1]
-
-        return m.group(1) + key + m.group(3) + value
+        v = m.group(0)
+        if v in ('true', 'false', 'null'):
+            return v
+        if v.startswith('"'):
+            return v
+        if v.startswith("'"):
+            v = v[1:-1]
+            v = re.sub(r"\\\\|\\'|\"", lambda m: {
+                '\\\\': '\\\\',
+                "\\'": "'",
+                '"': '\\"',
+            }[m.group(0)], v)
+        return '"%s"' % v
 
     res = re.sub(r'''(?x)
-            ([{,]\s*)
-            ("[^"]*"|\'[^\']*\'|[a-z0-9A-Z]+)
-            (:\s*)
-            ([0-9.]+|true|false|"[^"]*"|\'[^\']*\'|
-                (?=\[|\{)
-            )
+        "(?:[^"\\]*(?:\\\\|\\")?)*"|
+        '(?:[^'\\]*(?:\\\\|\\')?)*'|
+        [a-zA-Z_][a-zA-Z_0-9]*
         ''', fix_kv, code)
     res = re.sub(r',(\s*\])', lambda m: m.group(1), res)
     return res