Improve handling for overriding extractors with plugins (#5916)

* Extractors replaced with plugin extractors now show in debug output
* Better testcase handling
* Added documentation
Authored by: coletdjnz, pukkandan

yt_dlp/extractor/common.py

@@ -3442,13 +3442,17 @@ class InfoExtractor:
                 continue
             t['name'] = cls.ie_key()
             yield t
+        if getattr(cls, '__wrapped__', None):
+            yield from cls.__wrapped__.get_testcases(include_onlymatching)
 
     @classmethod
     def get_webpage_testcases(cls):
         tests = vars(cls).get('_WEBPAGE_TESTS', [])
         for t in tests:
             t['name'] = cls.ie_key()
-        return tests
+            yield t
+        if getattr(cls, '__wrapped__', None):
+            yield from cls.__wrapped__.get_webpage_testcases()
 
     @classproperty(cache=True)
     def age_limit(cls):
@@ -3710,10 +3714,12 @@ class InfoExtractor:
         if plugin_name:
             mro = inspect.getmro(cls)
             super_class = cls.__wrapped__ = mro[mro.index(cls) + 1]
-            cls.IE_NAME, cls.ie_key = f'{super_class.IE_NAME}+{plugin_name}', super_class.ie_key
+            cls.PLUGIN_NAME, cls.ie_key = plugin_name, super_class.ie_key
+            cls.IE_NAME = f'{super_class.IE_NAME}+{plugin_name}'
             while getattr(super_class, '__wrapped__', None):
                 super_class = super_class.__wrapped__
             setattr(sys.modules[super_class.__module__], super_class.__name__, cls)
+            _PLUGIN_OVERRIDES[super_class].append(cls)
 
         return super().__init_subclass__(**kwargs)
 
@@ -3770,3 +3776,6 @@ class UnsupportedURLIE(InfoExtractor):
 
     def _real_extract(self, url):
         raise UnsupportedError(url)
+
+
+_PLUGIN_OVERRIDES = collections.defaultdict(list)

yt_dlp/extractor/extractors.py

@@ -24,3 +24,5 @@ if not _LAZY_LOADER:
 
 globals().update(_PLUGIN_CLASSES)
 _ALL_CLASSES[:0] = _PLUGIN_CLASSES.values()
+
+from .common import _PLUGIN_OVERRIDES  # noqa: F401

yt_dlp/extractor/testurl.py

@@ -23,11 +23,12 @@ class TestURLIE(InfoExtractor):
         if len(matching_extractors) == 0:
             raise ExtractorError(f'No extractors matching {extractor_id!r} found', expected=True)
         elif len(matching_extractors) > 1:
-            try:  # Check for exact match
-                extractor = next(
-                    ie for ie in matching_extractors
-                    if ie.IE_NAME.lower() == extractor_id.lower())
-            except StopIteration:
+            extractor = next((  # Check for exact match
+                ie for ie in matching_extractors if ie.IE_NAME.lower() == extractor_id.lower()
+            ), None) or next((  # Check for exact match without plugin suffix
+                ie for ie in matching_extractors if ie.IE_NAME.split('+')[0].lower() == extractor_id.lower()
+            ), None)
+            if not extractor:
                 raise ExtractorError(
                     'Found multiple matching extractors: %s' % ' '.join(ie.IE_NAME for ie in matching_extractors),
                     expected=True)