add a test for imap capabilities offered from chatmail

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## untagged
 
+- Emit "XCHATMAIL" capability from IMAP server 
+  ([#278](https://github.com/deltachat/chatmail/pull/278))
+
 - Move echobot `into /var/lib/echobot`
   ([#281](https://github.com/deltachat/chatmail/pull/281))
 

cmdeploy/src/cmdeploy/dovecot/dovecot.conf.j2

@@ -27,7 +27,7 @@ mail_plugins = quota
 # these are the capabilities Delta Chat cares about actually 
 # so let's keep the network overhead per login small
 # https://github.com/deltachat/deltachat-core-rust/blob/master/src/imap/capabilities.rs
-imap_capability = IMAP4rev1 IDLE MOVE QUOTA CONDSTORE NOTIFY METADATA XDELTAPUSH
+imap_capability = IMAP4rev1 IDLE MOVE QUOTA CONDSTORE NOTIFY METADATA XDELTAPUSH XCHATMAIL
 
 
 # Authentication for system users.

cmdeploy/src/cmdeploy/tests/online/test_0_login.py

@@ -14,6 +14,13 @@ def test_init(tmp_path, maildomain):
     assert config.mail_domain == maildomain
 
 
+def test_capabilities(imap):
+    imap.connect()
+    capas = imap.conn.capabilities
+    assert "XCHATMAIL" in capas
+    assert "XDELTAPUSH" in capas
+
+
 def test_login_basic_functioning(imap_or_smtp, gencreds, lp):
     """Test a) that an initial login creates a user automatically
     and b) verify we can also login a second time with the same password