Assorted cleanup and a few type hints

.github/workflows/main.yml

@@ -34,7 +34,7 @@ jobs:
           fetch-depth: 0
       - name: Install ruff
         run: |
-          python3 -m pip install --break-system-packages ruff
+          python3 -m pip install --break-system-packages ruff mypy
       - name: Run ruff format
         run: |
           ruff --version
@@ -47,4 +47,8 @@ jobs:
         run: |
           ruff --version
           ruff check varlink
+      - name: Type Checking (mypy)
+        run: |
+          python3 -m mypy --version
+          python3 -m mypy varlink/
     runs-on: ubuntu-latest

varlink/client.py

@@ -217,7 +217,7 @@ def _send_message(self, out):
             self._connection.send_bytes(out + b"\0")
         elif self._sendall:
             self._connection.sendall(out + b"\0")
-        elif hasattr:
+        else:
             self._connection.write(out + b"\0")
 
     def _next_message(self):
@@ -245,15 +245,8 @@ def _next_message(self):
 
 
 def pipe_bridge(reader, writer):
-    if hasattr(reader, "recv"):
-        recv = True
-    else:
-        recv = False
-
-    if hasattr(writer, "sendall"):
-        sendall = True
-    else:
-        sendall = False
+    recv = hasattr(reader, "recv")
+    sendall = hasattr(writer, "sendall")
 
     while True:
         try:
@@ -272,7 +265,7 @@ def pipe_bridge(reader, writer):
         try:
             if sendall:
                 writer.sendall(data)
-            elif hasattr:
+            else:
                 writer.write(data)
                 writer.flush()
         except Exception:  # TODO: maybe just OsError?

varlink/scanner.py

@@ -10,11 +10,13 @@ class Scanner:
     """Class for scanning a varlink interface definition."""
 
     def __init__(self, string):
-        self.whitespace = re.compile(r"([ \t\n]|#.*$)+", re.ASCII | re.MULTILINE)
+        # whitespace or comment
+        wsc = r"([ \t\n]|#.*$)"
+        self.whitespace = re.compile(rf"{wsc}+", re.ASCII | re.MULTILINE)
         self.docstring = re.compile(r"(?:.?)+#(.*)(?:\n|\r\n)")
         # FIXME: nested ()
         self.method_signature = re.compile(
-            r"([ \t\n]|#.*$)*(\([^)]*\))([ \t\n]|#.*$)*->([ \t\n]|#.*$)*(\([^)]*\))",
+            rf"{wsc}*(\(.*?\)){wsc}*->{wsc}*(\(.*?\))",
             re.ASCII | re.MULTILINE,
         )
 
@@ -34,8 +36,7 @@ def __init__(self, string):
         self.current_doc = ""
 
     def get(self, expected):
-        m = self.whitespace.match(self.string, self.pos)
-        if m:
+        if m := self.whitespace.match(self.string, self.pos):
             doc = self.docstring.findall(self.string[m.start() : m.end()])
             if len(doc):
                 try:
@@ -44,10 +45,8 @@ def get(self, expected):
                     self.current_doc += "\n".join([el.decode("utf-8") for el in doc])
             self.pos = m.end()
 
-        pattern = self.patterns.get(expected)
-        if pattern:
-            m = pattern.match(self.string, self.pos)
-            if m:
+        if pattern := self.patterns.get(expected):
+            if m := pattern.match(self.string, self.pos):
                 self.pos = m.end()
                 return m.group(0)
         else:
@@ -57,14 +56,12 @@ def get(self, expected):
                 return True
 
     def expect(self, expected):
-        value = self.get(expected)
-        if not value:
-            raise SyntaxError(f"expected '{expected}'")
-        return value
+        if value := self.get(expected):
+            return value
+        raise SyntaxError(f"expected '{expected}'")
 
     def end(self):
-        m = self.whitespace.match(self.string, self.pos)
-        if m:
+        if m := self.whitespace.match(self.string, self.pos):
             doc = self.docstring.findall(self.string[m.start() : m.end()])
             if len(doc):
                 try:

varlink/server.py

@@ -13,6 +13,7 @@
     from socketserver import ForkingMixIn
 
 from types import GeneratorType
+from typing import Optional
 
 
 class Service:
@@ -324,7 +325,7 @@ class RequestHandler(StreamRequestHandler):
     Instantiate your own class and set the class variable service to your global :class:`Service` object.
     """
 
-    service = None
+    service: Optional[Service] = None
 
     def handle(self):
         message = b""

varlink/tests/test_certification.py

@@ -88,7 +88,7 @@ def __init__(self, wants, got):
 
 @service.interface("org.varlink.certification")
 class CertService:
-    next_method = {}
+    next_method: dict[str, str] = {}
 
     def new_client_id(self, _server):
         client_id = codecs.getencoder("hex")(os.urandom(16))[0].decode("ascii")
@@ -477,6 +477,8 @@ def usage():
         with varlink.Client.new_with_activate([__file__, "--varlink=$VARLINK_ADDRESS"]) as client:
             run_client(client)
     elif client_mode:
+        if client is None:
+            raise ValueError("--client requires at either of --varlink, --bridge or --activate")
         with client:
             run_client(client)
     else:

varlink/tests/test_mocks.py

@@ -12,21 +12,23 @@
 
 
 class Service:
-    def Test1(self, param1: int) -> str:
+    # TODO: these type annotations are wrong as Python type hints, but are used
+    # by varlink.mock.generate_callable_interface
+    def Test1(self, param1: int) -> str:  # type: ignore
         """return test: MyPersonalType"""
         return {
             "test": {
                 "foo": "bim",
                 "bar": "boom",
             },
-        }
+        }  # type: ignore
 
     def Test2(self, param1: str = "test") -> None:
         pass
 
-    def Test3(self, param1: str) -> str:
+    def Test3(self, param1: str) -> str:  # type: ignore
         """return test"""
-        return {"test": param1}
+        return {"test": param1}  # type: ignore
 
 
 class TestMockMechanisms(unittest.TestCase):

varlink/tests/test_orgexamplemore.py

@@ -200,6 +200,8 @@ def epilog():
         with varlink.Client.new_with_activate([__file__, "--varlink=$VARLINK_ADDRESS"]) as client:
             run_client(client)
     elif client_mode:
+        if client is None:
+            raise ValueError("--client requires at either of --varlink, --bridge or --activate")
         with client:
             run_client(client)
     else: