Fix slackapi#650 Deprecation warnings to channels/groups/mpim/im API …

…method calls

slack/web/__init__.py

@@ -1,5 +1,6 @@
 import platform
 import sys
+import warnings
 
 import slack.version as ver
 
@@ -18,3 +19,25 @@ def get_user_agent():
     system_info = "{0}/{1}".format(platform.system(), platform.release())
     user_agent_string = " ".join([python_version, client, system_info])
     return user_agent_string
+
+
+# https://api.slack.com/changelog/2020-01-deprecating-antecedents-to-the-conversations-api
+deprecated_method_prefixes_2020_01 = ["channels.", "groups.", "im.", "mpim."]
+
+
+def show_2020_01_deprecation(method_name: str):
+    if not method_name:
+        return
+
+    matched_prefixes = [
+        prefix
+        for prefix in deprecated_method_prefixes_2020_01
+        if method_name.startswith(prefix)
+    ]
+    if len(matched_prefixes) > 0:
+        message = (
+            f"{method_name} is deprecated. Please use the Conversations API instead. "
+            f"For more info, go to "
+            f"https://api.slack.com/changelog/2020-01-deprecating-antecedents-to-the-conversations-api"
+        )
+        warnings.warn(message)

slack/web/base_client.py

@@ -14,7 +14,7 @@
 from aiohttp import FormData, BasicAuth
 
 # Internal Imports
-from slack.web import get_user_agent
+from slack.web import get_user_agent, show_2020_01_deprecation
 from slack.web.slack_response import SlackResponse
 import slack.errors as err
 from slack.web.urllib_client import UrllibWebClient
@@ -167,6 +167,9 @@ def api_call(
         }
 
         if self.run_async or self.use_sync_aiohttp:
+            # NOTE: For sync mode client, show_2020_01_deprecation(str) is called inside UrllibClient
+            show_2020_01_deprecation(api_method)
+
             if self._event_loop is None:
                 self._event_loop = self._get_event_loop()
 

slack/web/urllib_client.py

@@ -10,7 +10,7 @@
 from urllib.parse import urlencode
 from urllib.request import Request, urlopen
 
-from slack.web import get_user_agent
+from slack.web import get_user_agent, show_2020_01_deprecation
 from slack.web.slack_response import SlackResponse
 
 
@@ -63,6 +63,9 @@ def api_call(
         :param additional_headers: request headers to append
         :return: API response
         """
+
+        show_2020_01_deprecation(self._to_api_method(url))
+
         files_to_close: List[BinaryIO] = []
         try:
             if self.logger.level <= logging.DEBUG:
@@ -243,3 +246,10 @@ def _build_request_headers(
             # will be set afterwards
             headers.pop("Content-Type", None)
         return headers
+
+    def _to_api_method(self, url: str):
+        if url:
+            elements = url.split("/")
+            if elements and len(elements) > 0:
+                return elements[len(elements) - 1].split("?", 1)[0]
+        return None