Add documentation and tests

docs/usage.md

@@ -136,7 +136,9 @@ These rules perform the following:
 
 Paperless will check all emails only once and completely ignore messages
 that do not match your filters. It will also only perform the rule action
-on e-mails that it has consumed documents from.
+on e-mails that it has consumed documents from. The filename attachment
+exclusion pattern could be splitted by commto to allow different exclusion
+patterns.
 
 The actions all ensure that the same mail is not consumed twice by
 different means. These are as follows:

src/paperless_mail/tests/test_mail.py

@@ -592,6 +592,18 @@ class TestMail(
                 exclude_pattern="f1*",
                 expected_matches=["f2.pdf", "f3.pdf", "file.PDf"],
             ),
+            FilterTestCase(
+                "PDF Files without f1 and f2",
+                include_pattern="*.pdf",
+                exclude_pattern="f1*,f2*",
+                expected_matches=["f3.pdf", "file.PDf"],
+            ),
+            FilterTestCase(
+                "PDF Files without f1 and f2 and f3",
+                include_pattern="*.pdf",
+                exclude_pattern="f1*,f2*,f3*",
+                expected_matches=[list"file.PDf"],
+            ),
             FilterTestCase(
                 "All Files, no PNG",
                 include_pattern="*",