[wikimedia] support fandom wikis (#1443, #2677, #3378)

Wikis hosted on fandom.com are just wikimedia instances
and support its API.

docs/supportedsites.md

@@ -1523,6 +1523,12 @@ Consider all listed sites to potentially be NSFW.
     <td>Articles</td>
     <td></td>
 </tr>
+<tr>
+    <td>Fandom</td>
+    <td>https://www.fandom.com/</td>
+    <td>Articles</td>
+    <td></td>
+</tr>
 <tr>
     <td>Super Mario Wiki</td>
     <td>https://www.mariowiki.com/</td>

gallery_dl/extractor/wikimedia.py

@@ -25,6 +25,10 @@ class WikimediaExtractor(BaseExtractor):
         BaseExtractor.__init__(self, match)
         path = match.group(match.lastindex)
 
+        if self.category == "fandom":
+            self.category = \
+                "fandom-" + self.root.partition(".")[0].rpartition("/")[2]
+
         if path.startswith("wiki/"):
             path = path[5:]
             self.api_path = "/w/api.php"
@@ -158,6 +162,11 @@ BASE_PATTERN = WikimediaExtractor.update({
         "root": "https://www.mediawiki.org",
         "pattern": r"(?:www\.)?mediawiki\.org",
     },
+    "fandom": {
+        "root": None,
+        "pattern": r"[\w-]+\.fandom\.com",
+        "api-path": "/api.php",
+    },
     "mariowiki": {
         "root": "https://www.mariowiki.com",
         "pattern": r"(?:www\.)?mariowiki\.com",

test/results/fandom.py

@@ -0,0 +1,92 @@
+# -*- coding: utf-8 -*-
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+
+from gallery_dl.extractor import wikimedia
+
+
+__tests__ = (
+{
+    "#url"     : "https://www.fandom.com/wiki/Title",
+    "#comment" : "for scripts/supportedsites.py",
+    "#category": ("wikimedia", "fandom-www", "article"),
+    "#class"   : wikimedia.WikimediaArticleExtractor,
+},
+
+{
+    "#url"     : "https://mushishi.fandom.com/wiki/Yahagi",
+    "#category": ("wikimedia", "fandom-mushishi", "article"),
+    "#class"   : wikimedia.WikimediaArticleExtractor,
+    "#urls"    : "https://static.wikia.nocookie.net/mushi-shi/images/f/f8/Yahagi.png/revision/latest?cb=20150128052255",
+
+    "bitdepth"      : 8,
+    "canonicaltitle": "File:Yahagi.png",
+    "comment"       : "",
+    "commonmetadata": {
+        "ResolutionUnit": 3,
+        "XResolution"   : "3779/100",
+        "YResolution"   : "3779/100",
+    },
+    "date"          : "dt:2015-01-28 05:22:55",
+    "descriptionshorturl": "https://mushishi.fandom.com/index.php?curid=2595",
+    "descriptionurl": "https://mushishi.fandom.com/wiki/File:Yahagi.png",
+    "extension"     : "png",
+    "extmetadata"   : {
+        "DateTime": {
+            "hidden": "",
+            "source": "mediawiki-metadata",
+            "value": "2015-01-28T05:22:55Z",
+        },
+        "ObjectName": {
+            "hidden": "",
+            "source": "mediawiki-metadata",
+            "value": "Yahagi",
+        },
+    },
+    "filename"      : "Yahagi",
+    "height"        : 410,
+    "metadata"      : {
+        "bitDepth"  : 8,
+        "colorType" : "truecolour",
+        "duration"  : 0,
+        "frameCount": 0,
+        "loopCount" : 1,
+        "metadata"  : [
+            {
+                "name" : "XResolution",
+                "value": "3779/100",
+            },
+            {
+                "name" : "YResolution",
+                "value": "3779/100",
+            },
+            {
+                "name" : "ResolutionUnit",
+                "value": 3,
+            },
+            {
+                "name" : "_MW_PNG_VERSION",
+                "value": 1,
+            },
+        ],
+    },
+    "mime"          : "image/png",
+    "page"          : "Yahagi",
+    "sha1"          : "e3078a97976215323dbabb0c86b7acc55b512d16",
+    "size"          : 429912,
+    "timestamp"     : "2015-01-28T05:22:55Z",
+    "url"           : "https://static.wikia.nocookie.net/mushi-shi/images/f/f8/Yahagi.png/revision/latest?cb=20150128052255",
+    "user"          : "ITHYRIAL",
+    "userid"        : 4637089,
+    "width"         : 728,
+},
+
+{
+    "#url"     : "https://projectsekai.fandom.com/wiki/Project_SEKAI_Wiki",
+    "#category": ("wikimedia", "fandom-projectsekai", "article"),
+    "#class"   : wikimedia.WikimediaArticleExtractor,
+},
+
+)