tests: test mail attachments mimetypes

canaille/app/mails.py

@@ -40,8 +40,10 @@ def logo():
 
 def type_from_filename(filename):
     filetype = mimetypes.guess_type(filename)
-    if not filetype or not filetype[0]:  # pragma: no cover
+    if not filetype or not filetype[0]:
         # For some reasons GHA fails to guess webp mimetypes
+        # According to MDN, the default mimetype should be application/octet-stream
+        # https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types
         return "application", "octet-stream"
 
     maintype, subtype = filetype[0].split("/")

tests/app/test_mails.py

@@ -6,6 +6,7 @@
 from flask_webtest import TestApp
 
 from canaille import create_app
+from canaille.app.mails import type_from_filename
 
 
 @pytest.fixture
@@ -224,3 +225,8 @@ def test_default_from_flask_server_name(configuration, user, smtpd, backend):
     res = res.form.submit(status=200)
     assert smtpd.messages[0]["X-MailFrom"] == "[email protected]"
     assert smtpd.messages[0]["From"] == '"Canaille" <[email protected]>'
+
+
+def test_type_from_filename():
+    assert type_from_filename("index.html") == ("text", "html")
+    assert type_from_filename("unknown") == ("application", "octet-stream")