write a happy path test

chatmaild/src/chatmaild/metadata.py

@@ -11,28 +11,58 @@ import os
 import requests
 
 
+DICTPROXY_LOOKUP_CHAR = "L"
+DICTPROXY_SET_CHAR = "S"
+DICTPROXY_BEGIN_TRANSACTION_CHAR = "B"
+DICTPROXY_COMMIT_TRANSACTION_CHAR = "C"
+DICTPROXY_TRANSACTION_CHARS = "SBC"
+
+
 def handle_dovecot_protocol(rfile, wfile, tokens, requests_session, config: Config):
     # HELLO message, ignored.
     msg = rfile.readline().strip().decode()
 
-    transactions = {}
+    def post_with_token(token):
+        response = requests_session.post(
+            "https://notifications.delta.chat/notify",
+            data=token,
+            timeout=60,
+        )
+        if response.status_code == 410:
+            # 410 Gone status code
+            # means the token is no longer valid.
+            del tokens[guid]
 
+    transactions = {}
     while True:
         msg = rfile.readline().strip().decode()
         if not msg:
             break
 
-        res = handle_dovecot_request(msg, tokens, requests_session, config)
+        res = handle_dovecot_request(msg, transactions, tokens, post_with_token)
         if res:
             wfile.write(res.encode("ascii"))
             wfile.flush()
 
 
-def handle_dovecot_request(msg, tokens, requests_session, config: Config):
+def handle_dovecot_request(msg, transactions, tokens, post_with_token):
+    # see https://doc.dovecot.org/3.0/developer_manual/design/dict_protocol/
     short_command = msg[0]
-    if short_command == "L":
+    parts = msg[1:].split("\t")
+    if short_command == DICTPROXY_LOOKUP_CHAR:
         return b"N\n"
-    elif short_command == "S":
+
+    if short_command not in (DICTPROXY_TRANSACTION_CHARS):
+        return
+
+    transaction_id = parts[0]
+
+    if short_command == DICTPROXY_BEGIN_TRANSACTION_CHAR:
+        transactions[transaction_id] = b"O\n"
+    elif short_command == DICTPROXY_COMMIT_TRANSACTION_CHAR:
+        # returns whether it failed or succeeded.
+        return transactions.pop(transaction_id, b"N\n")
+    elif short_command == DICTPROXY_SET_CHAR:
         # See header of
         # <https://github.com/dovecot/core/blob/5e7965632395793d9355eb906b173bf28d2a10ca/src/lib-storage/mailbox-attribute.h>
         # for the documentation on the structure of the key.
@@ -45,8 +75,6 @@ def handle_dovecot_request(msg, tokens, requests_session, config: Config):
         # results in
         # priv/dd72550f05eadc65542a1200cac67ad7/vendor/vendor.dovecot/pvt/server/chatmail
 
-        parts = msg[1:].split("\t")
-        transaction_id = parts[0]
         keyname = parts[1].split("/")
         value = parts[2] if len(parts) > 2 else ""
         if keyname[0] == "priv" and keyname[2] == "devicetoken":
@@ -55,26 +83,10 @@ def handle_dovecot_request(msg, tokens, requests_session, config: Config):
             guid = keyname[1]
             token = tokens.get(guid)
             if token:
-                response = requests_session.post(
+                post_with_token(token)
-                    "https://notifications.delta.chat/notify",
-                    data=token,
-                    timeout=60,
-                )
-                if response.status_code == 410:
-                    # 410 Gone status code
-                    # means the token is no longer valid.
-                    del tokens[guid]
         else:
             # Transaction failed.
             transactions[transaction_id] = b"F\n"
-    elif short_command == "B":
-        # Begin transaction.
-        transaction_id = msg[1:].split("\t")[0]
-        transactions[transaction_id] = b"O\n"
-    elif short_command == "C":
-        # Commit transaction.
-        transaction_id = msg[1:].split("\t")[0]
-        return transactions.pop(transaction_id, b"N\n")
 
 
 class ThreadedUnixStreamServer(ThreadingMixIn, UnixStreamServer):
@@ -84,6 +96,8 @@ class ThreadedUnixStreamServer(ThreadingMixIn, UnixStreamServer):
 def main():
     socket, username, config = sys.argv[1:]
     passwd_entry = pwd.getpwnam(username)
+
+    # XXX config is not currently used
     config = read_config(config)
     tokens = {}
     requests_session = requests.Session()

chatmaild/src/chatmaild/tests/test_metadata.py

@@ -0,0 +1,41 @@
+from chatmaild.metadata import (
+    handle_dovecot_request,
+)
+
+
+def test_handle_dovecot_request_happy_path():
+    tokens = {}
+    transactions = {}
+
+    # lookups return the same NOTFOUND result
+    res = handle_dovecot_request("Lpriv/123/chatmail", transactions, tokens, None)
+    assert res == b"N\n"
+    assert not tokens and not transactions
+
+    # set device token in a transaction
+    tx = "1111"
+    msg = f"B{tx}\tuser"
+    res = handle_dovecot_request(msg, transactions, tokens, None)
+    assert not res and not tokens
+    assert transactions == {tx: b"O\n"}
+
+    msg = f"S{tx}\tpriv/guid00/devicetoken\t01234"
+    res = handle_dovecot_request(msg, transactions, tokens, None)
+    assert not res
+    assert len(transactions) == 1
+    assert len(tokens) == 1 and tokens["guid00"] == "01234"
+
+    msg = f"C{tx}"
+    res = handle_dovecot_request(msg, transactions, tokens, None)
+    assert res == b"O\n"
+    assert len(transactions) == 0
+    assert tokens["guid00"] == "01234"
+
+    # trigger notification for incoming message
+    assert handle_dovecot_request(f"B{tx}\tuser", transactions, tokens, None) is None
+    msg = f"S{tx}\tpriv/guid00/messagenew"
+    requests = []
+    assert handle_dovecot_request(msg, transactions, tokens, requests.append) is None
+    assert requests == ["01234"]
+    assert handle_dovecot_request(f"C{tx}\tuser", transactions, tokens, None) == b"O\n"
+    assert not transactions