Allow _TESTS attribute for IEs with multiple tests

This also improves the numbering of duplicate tests

test/test_download.py

@@ -63,6 +63,9 @@ for ie in youtube_dl.extractor.gen_extractors():
     if t:
         t['name'] = type(ie).__name__[:-len('IE')]
         defs.append(t)
+    for t in getattr(ie, '_TESTS', []):
+        t['name'] = type(ie).__name__[:-len('IE')]
+        defs.append(t)
 
 
 with io.open(PARAMETERS_FILE, encoding='utf-8') as pf:
@@ -162,9 +165,12 @@ def generator(test_case):
 ### And add them to TestDownload
 for n, test_case in enumerate(defs):
     test_method = generator(test_case)
-    test_method.__name__ = "test_{0}".format(test_case["name"])
-    if getattr(TestDownload, test_method.__name__, False):
-        test_method.__name__ = "test_{0}_{1}".format(test_case["name"], n)
+    tname = 'test_' + str(test_case['name'])
+    i = 1
+    while hasattr(TestDownload, tname):
+        tname = 'test_'  + test_case['name'] + '_' + str(i)
+        i += 1
+    test_method.__name__ = tname
     setattr(TestDownload, test_method.__name__, test_method)
     del test_method
 

test/tests.json

@@ -1,42 +1,4 @@
 [
-  {
-    "name": "Youtube",
-    "url":  "http://www.youtube.com/watch?v=BaW_jenozKc",
-    "file":  "BaW_jenozKc.mp4",
-    "info_dict": {
-      "title": "youtube-dl test video \"'/\\ä↭𝕐",
-      "uploader": "Philipp Hagemeister",
-      "uploader_id": "phihag",
-      "upload_date": "20121002",
-      "description": "test chars:  \"'/\\ä↭𝕐\n\nThis is a test video for youtube-dl.\n\nFor more information, contact phihag@phihag.de ."
-    }
-  },
-  {
-    "name": "Youtube",
-    "url":  "http://www.youtube.com/watch?v=1ltcDfZMA3U",
-    "file":  "1ltcDfZMA3U.flv",
-    "note": "Test VEVO video (#897)",
-    "info_dict": {
-      "upload_date": "20070518",
-      "title": "Maps - It Will Find You",
-      "description": "Music video by Maps performing It Will Find You.",
-      "uploader": "MuteUSA",
-      "uploader_id": "MuteUSA"
-    }
-  },
-  {
-    "name": "Youtube",
-    "url":  "http://www.youtube.com/watch?v=UxxajLWwzqY",
-    "file":  "UxxajLWwzqY.mp4",
-    "note": "Test generic use_cipher_signature video (#897)",
-    "info_dict": {
-      "upload_date": "20120506",
-      "title": "Icona Pop - I Love It (feat. Charli XCX) [OFFICIAL VIDEO]",
-      "description": "md5:b085c9804f5ab69f4adea963a2dceb3c",
-      "uploader": "IconaPop",
-      "uploader_id": "IconaPop"
-    }
-  },
   {
     "name": "Dailymotion",
     "md5":  "392c4b85a60a90dc4792da41ce3144eb",