Add Filters.attachment (#2528)

* feat: attachment filter

* fix: add versionadded statement

* Fix: small doc string changes

Co-authored-by: Bibo-Joshi <hinrich.mahler@freenet.de>

Co-authored-by: Bibo-Joshi <hinrich.mahler@freenet.de>

telegram/ext/filters.py

@@ -2075,6 +2075,18 @@ officedocument.wordprocessingml.document")``.
                 and any(message.from_user.language_code.startswith(x) for x in self.lang)
             )
 
+    class _Attachment(MessageFilter):
+        name = 'Filters.attachment'
+
+        def filter(self, message: Message) -> bool:
+            return bool(message.effective_attachment)
+
+    attachment = _Attachment()
+    """Messages that contain :meth:`telegram.Message.effective_attachment`.
+
+
+        .. versionadded:: 13.6"""
+
     class _UpdateType(UpdateFilter):
         name = 'Filters.update'
 

tests/test_filters.py

@@ -2173,3 +2173,18 @@ class TestFilters:
 
         with pytest.raises(RuntimeError, match='Cannot set name'):
             f.name = 'foo'
+
+    def test_filters_attachment(self, update):
+        assert not Filters.attachment(update)
+        # we need to define a new Update (or rather, message class) here because
+        # effective_attachment is only evaluated once per instance, and the filter relies on that
+        up = Update(
+            0,
+            Message(
+                0,
+                datetime.datetime.utcnow(),
+                Chat(0, 'private'),
+                document=Document("str", "other_str"),
+            ),
+        )
+        assert Filters.attachment(up)