Introduction of the imgur.com SPECIAL rule.

This patch fixes #319.

Indeed, before this patch we weren't handling the case that a
hosted image or user has been deleted.

Contributors:
  * @smed79

PyFunceble/checker/availability/extras/rules.py

@@ -92,6 +92,7 @@ def __init__(self, status: Optional[AvailabilityCheckerStatus] = None) -> None:
             r"\.github\.io$": [(self.__switch_to_down_if, 404)],
             r"\.godaddysites\.com$": [(self.__switch_to_down_if, 404)],
             r"\.hpg.com.br$": [(self.__switch_to_down_if, 404)],
+            r"\.imgur\.com$": [self.__handle_imgur_dot_com],
             r"\.liveadvert\.com$": [(self.__switch_to_down_if, 404)],
             r"\.skyrock\.com$": [(self.__switch_to_down_if, 404)],
             r"\.tumblr\.com$": [(self.__switch_to_down_if, 404)],
@@ -152,9 +153,7 @@ def __regex_registry_handler(self, regex_registry: dict) -> "ExtraRulesHandler":
         ) in regex_registry.items():
             broken = False
             for element in data:
-                if not RegexHelper(regex).match(
-                    self.status.idna_subject, return_match=False
-                ):
+                if not RegexHelper(regex).match(self.status.netloc, return_match=False):
                     continue
 
                 if isinstance(element, tuple):
@@ -246,6 +245,40 @@ def __handle_fc2_dot_com(self) -> "ExtraRulesHandler":
 
         return self
 
+    def __handle_imgur_dot_com(self) -> "ExtraRulesHandler":
+        """
+        Handles the :code:`imgur.com` case.
+
+        .. warning:.
+            This method assume that we know that we are handling a imgur.com
+            sub-domain.
+        """
+
+        if self.status.idna_subject.startswith(
+            "http:"
+        ) or self.status.idna_subject.startswith("https://"):
+            url = self.status.idna_subject
+        else:
+            url = f"https://{self.status.idna_subject}"
+
+        req = PyFunceble.factory.Requester.get(url, allow_redirects=True)
+        username = self.status.netloc.replace(".imgur.com", "")
+
+        for response in req.history:
+            if "Location" in req.response:
+                if req.headers["Location"].endswith(("/removed.png")):
+                    self.switch_to_down()
+
+                if response.status_code in [404] and response.url.endswith(
+                    f"/user/{username}"
+                ):
+                    self.switch_to_down()
+
+        if req.url.endswith(f"/user/{username}"):
+            self.switch_to_down()
+
+        return self
+
     def __handle_active2inactive(self) -> "ExtraRulesHandler":
         """
         Handles the status deescalation.

docs/components/special-rules.rst

@@ -319,6 +319,17 @@ supplied as :code:`INACTIVE`.
 
 ------
 
+:code:`*.imgur.com`
+"""""""""""""""""""
+
+Any subjects matching the given pattern and:
+
+    - the :code:`/removed.png` path in the end URL (after redirect).
+
+are supplied as :code:`INACTIVE`.
+
+------
+
 :code:`*.liveadvert.com`
 """"""""""""""""""""""""