Add mypy check (#779)

.pre-commit-config.yaml

@@ -28,6 +28,13 @@ repos:
         files: \.py$
         args: [--profile=black]
 
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v0.942
+    hooks:
+      - id: mypy
+        exclude: examples/simple/setup.py
+        additional_dependencies: [types-requests]
+
   - repo: https://github.com/pre-commit/mirrors-prettier
     rev: v2.6.2
     hooks:

docs/source/conf.py

@@ -16,7 +16,7 @@
 import shutil
 import sys
 
-from pkg_resources import parse_version
+from packaging.version import parse as parse_version
 
 HERE = osp.abspath(osp.dirname(__file__))
 

examples/authorization/jupyter_nbclassic_readonly_config.py

@@ -11,4 +11,4 @@ def is_authorized(self, handler, user, action, resource):
         return True
 
 
-c.ServerApp.authorizer_class = ReadOnly
+c.ServerApp.authorizer_class = ReadOnly  # type:ignore[name-defined]

examples/authorization/jupyter_nbclassic_rw_config.py

@@ -11,4 +11,4 @@ def is_authorized(self, handler, user, action, resource):
         return True
 
 
-c.ServerApp.authorizer_class = ReadWriteOnly
+c.ServerApp.authorizer_class = ReadWriteOnly  # type:ignore[name-defined]

examples/authorization/jupyter_temporary_config.py

@@ -11,4 +11,4 @@ def is_authorized(self, handler, user, action, resource):
         return True
 
 
-c.ServerApp.authorizer_class = TemporaryServerPersonality
+c.ServerApp.authorizer_class = TemporaryServerPersonality  # type:ignore[name-defined]

examples/simple/jupyter_server_config.py

@@ -3,4 +3,6 @@
 # Application(SingletonConfigurable) configuration
 # ------------------------------------------------------------------------------
 # The date format used by logging formatters for %(asctime)s
-c.Application.log_datefmt = "%Y-%m-%d %H:%M:%S Simple_Extensions_Example"
+c.Application.log_datefmt = (  # type:ignore[name-defined]
+    "%Y-%m-%d %H:%M:%S Simple_Extensions_Example"
+)

examples/simple/jupyter_simple_ext11_config.py

@@ -1 +1 @@
-c.SimpleApp11.ignore_js = True
+c.SimpleApp11.ignore_js = True  # type:ignore[name-defined]

examples/simple/jupyter_simple_ext1_config.py

@@ -1,4 +1,4 @@
-c.SimpleApp1.configA = "ConfigA from file"
-c.SimpleApp1.configB = "ConfigB from file"
-c.SimpleApp1.configC = "ConfigC from file"
-c.SimpleApp1.configD = "ConfigD from file"
+c.SimpleApp1.configA = "ConfigA from file"  # type:ignore[name-defined]
+c.SimpleApp1.configB = "ConfigB from file"  # type:ignore[name-defined]
+c.SimpleApp1.configC = "ConfigC from file"  # type:ignore[name-defined]
+c.SimpleApp1.configD = "ConfigD from file"  # type:ignore[name-defined]

examples/simple/jupyter_simple_ext2_config.py

@@ -1 +1 @@
-c.SimpleApp2.configD = "ConfigD from file"
+c.SimpleApp2.configD = "ConfigD from file"  # type:ignore[name-defined]

jupyter_server/auth/login.py

@@ -83,7 +83,7 @@ def post(self):
             elif self.token and self.token == typed_password:
                 self.set_login_cookie(self, uuid.uuid4().hex)
                 if new_password and self.settings.get("allow_password_change"):
-                    config_dir = self.settings.get("config_dir")
+                    config_dir = self.settings.get("config_dir", "")
                     config_file = os.path.join(config_dir, "jupyter_server_config.json")
                     set_password(new_password, config_file=config_file)
                     self.log.info("Wrote hashed password to %s" % config_file)

jupyter_server/auth/security.py

@@ -64,9 +64,9 @@ def passwd(passphrase=None, algorithm="argon2"):
             time_cost=10,
             parallelism=8,
         )
-        h = ph.hash(passphrase)
+        h_ph = ph.hash(passphrase)
 
-        return ":".join((algorithm, h))
+        return ":".join((algorithm, h_ph))
 
     h = hashlib.new(algorithm)
     salt = ("%0" + str(salt_len) + "x") % random.getrandbits(4 * salt_len)

jupyter_server/auth/utils.py

@@ -39,9 +39,9 @@ def get_regex_to_resource_map():
     from jupyter_server.serverapp import JUPYTER_SERVICE_HANDLERS
 
     modules = []
-    for mod in JUPYTER_SERVICE_HANDLERS.values():
-        if mod:
-            modules.extend(mod)
+    for mod_name in JUPYTER_SERVICE_HANDLERS.values():
+        if mod_name:
+            modules.extend(mod_name)
     resource_map = {}
     for handler_module in modules:
         mod = importlib.import_module(handler_module)

jupyter_server/base/handlers.py

@@ -115,7 +115,7 @@ def force_clear_cookie(self, name, path="/", domain=None):
         name = escape.native_str(name)
         expires = datetime.datetime.utcnow() - datetime.timedelta(days=365)
 
-        morsel = Morsel()
+        morsel: Morsel = Morsel()
         morsel.set(name, "", '""')
         morsel["expires"] = httputil.format_timestamp(expires)
         morsel["path"] = path
@@ -292,7 +292,7 @@ def mathjax_config(self):
         return self.settings.get("mathjax_config", "TeX-AMS-MML_HTMLorMML-full,Safe")
 
     @property
-    def base_url(self):
+    def base_url(self) -> str:
         return self.settings.get("base_url", "/")
 
     @property
@@ -537,7 +537,9 @@ def check_host(self):
             return True
 
         # Remove port (e.g. ':8888') from host
-        host = re.match(r"^(.*?)(:\d+)?$", self.request.host).group(1)
+        match = re.match(r"^(.*?)(:\d+)?$", self.request.host)
+        assert match is not None
+        host = match.group(1)
 
         # Browsers format IPv6 addresses like [::1]; we need to remove the []
         if host.startswith("[") and host.endswith("]"):
@@ -574,10 +576,10 @@ async def prepare(self):
 
         from jupyter_server.auth import IdentityProvider
 
-        if (
-            type(self.identity_provider) is IdentityProvider
-            and inspect.getmodule(self.get_current_user).__name__ != __name__
-        ):
+        mod_obj = inspect.getmodule(self.get_current_user)
+        assert mod_obj is not None
+
+        if type(self.identity_provider) is IdentityProvider and mod_obj.__name__ != __name__:
             # check for overridden get_current_user + default IdentityProvider
             # deprecated way to override auth (e.g. JupyterHub < 3.0)
             # allow deprecated, overridden get_current_user
@@ -659,7 +661,7 @@ def write_error(self, status_code, **kwargs):
         exc_info = kwargs.get("exc_info")
         message = ""
         status_message = responses.get(status_code, "Unknown HTTP Error")
-        exception = "(unknown)"
+
         if exc_info:
             exception = exc_info[1]
             # get the custom message, if defined
@@ -672,6 +674,8 @@ def write_error(self, status_code, **kwargs):
             reason = getattr(exception, "reason", "")
             if reason:
                 status_message = reason
+        else:
+            exception = "(unknown)"
 
         # build template namespace
         ns = dict(
@@ -703,7 +707,7 @@ def write_error(self, status_code, **kwargs):
         """APIHandler errors are JSON, not human pages"""
         self.set_header("Content-Type", "application/json")
         message = responses.get(status_code, "Unknown HTTP Error")
-        reply = {
+        reply: dict = {
             "message": message,
         }
         exc_info = kwargs.get("exc_info")
@@ -817,13 +821,14 @@ def head(self, path):
 
     @web.authenticated
     def get(self, path):
-        if os.path.splitext(path)[1] == ".ipynb" or self.get_argument("download", False):
+        if os.path.splitext(path)[1] == ".ipynb" or self.get_argument("download", None):
             name = path.rsplit("/", 1)[-1]
             self.set_attachment_header(name)
 
         return web.StaticFileHandler.get(self, path)
 
     def get_content_type(self):
+        assert self.absolute_path is not None
         path = self.absolute_path.strip("/")
         if "/" in path:
             _, name = path.rsplit("/", 1)
@@ -902,7 +907,8 @@ class FileFindHandler(JupyterHandler, web.StaticFileHandler):
     """subclass of StaticFileHandler for serving files from a search path"""
 
     # cache search results, don't search for files more than once
-    _static_paths = {}
+    _static_paths: dict = {}
+    root: tuple
 
     def set_headers(self):
         super().set_headers()
@@ -966,6 +972,7 @@ class TrailingSlashHandler(web.RequestHandler):
     """
 
     def get(self):
+        assert self.request.uri is not None
         path, *rest = self.request.uri.partition("?")
         # trim trailing *and* leading /
         # to avoid misinterpreting repeated '//'

jupyter_server/base/zmqhandlers.py

@@ -5,6 +5,7 @@
 import re
 import struct
 import sys
+from typing import Optional, no_type_check
 from urllib.parse import urlparse
 
 import tornado
@@ -17,6 +18,7 @@
 from jupyter_client.jsonutil import extract_dates
 from jupyter_client.session import Session
 from tornado import ioloop, web
+from tornado.iostream import IOStream
 from tornado.websocket import WebSocketHandler
 
 from .handlers import JupyterHandler
@@ -91,7 +93,7 @@ def serialize_msg_to_ws_v1(msg_or_list, channel, pack=None):
     else:
         msg_list = msg_or_list
     channel = channel.encode("utf-8")
-    offsets = []
+    offsets: list = []
     offsets.append(8 * (1 + 1 + len(msg_list) + 1))
     offsets.append(len(channel) + offsets[-1])
     for msg in msg_list:
@@ -120,27 +122,30 @@ class WebSocketMixin:
     """Mixin for common websocket options"""
 
     ping_callback = None
-    last_ping = 0
-    last_pong = 0
-    stream = None
+    last_ping = 0.0
+    last_pong = 0.0
+    stream = None  # type: Optional[IOStream]
 
     @property
     def ping_interval(self):
         """The interval for websocket keep-alive pings.
 
         Set ws_ping_interval = 0 to disable pings.
         """
-        return self.settings.get("ws_ping_interval", WS_PING_INTERVAL)
+        return self.settings.get("ws_ping_interval", WS_PING_INTERVAL)  # type:ignore[attr-defined]
 
     @property
     def ping_timeout(self):
         """If no ping is received in this many milliseconds,
         close the websocket connection (VPNs, etc. can fail to cleanly close ws connections).
         Default is max of 3 pings or 30 seconds.
         """
-        return self.settings.get("ws_ping_timeout", max(3 * self.ping_interval, WS_PING_INTERVAL))
+        return self.settings.get(  # type:ignore[attr-defined]
+            "ws_ping_timeout", max(3 * self.ping_interval, WS_PING_INTERVAL)
+        )
 
-    def check_origin(self, origin=None):
+    @no_type_check
+    def check_origin(self, origin: Optional[str] = None) -> bool:
         """Check Origin == Host or Access-Control-Allow-Origin.
 
         Tornado >= 4 calls this method automatically, raising 403 if it returns False.
@@ -186,6 +191,7 @@ def clear_cookie(self, *args, **kwargs):
         """meaningless for websockets"""
         pass
 
+    @no_type_check
     def open(self, *args, **kwargs):
         self.log.debug("Opening websocket %s", self.request.path)
 
@@ -201,6 +207,7 @@ def open(self, *args, **kwargs):
             self.ping_callback.start()
         return super().open(*args, **kwargs)
 
+    @no_type_check
     def send_ping(self):
         """send a ping to keep the websocket alive"""
         if self.ws_connection is None and self.ping_callback is not None:
@@ -322,7 +329,7 @@ def pre_get(self):
         if not self.authorizer.is_authorized(self, user, "execute", "kernels"):
             raise web.HTTPError(403)
 
-        if self.get_argument("session_id", False):
+        if self.get_argument("session_id", None):
             self.session.session = self.get_argument("session_id")
         else:
             self.log.warning("No session ID specified")

jupyter_server/config_manager.py

@@ -95,7 +95,7 @@ def get(self, section_name, include_root=True):
             section_name,
             "\n\t".join(paths),
         )
-        data = {}
+        data: dict = {}
         for path in paths:
             if os.path.isfile(path):
                 with open(path, encoding="utf-8") as f:

jupyter_server/extension/application.py

@@ -137,7 +137,7 @@ class method. This method can be set as a entry_point in
     # A useful class property that subclasses can override to
     # configure the underlying Jupyter Server when this extension
     # is launched directly (using its `launch_instance` method).
-    serverapp_config = {}
+    serverapp_config: dict = {}
 
     # Some subclasses will likely override this trait to flip
     # the default value to False if they don't offer a browser
@@ -165,7 +165,7 @@ def config_file_paths(self):
     # file, jupyter_{name}_config.
     # This should also match the jupyter subcommand used to launch
     # this extension from the CLI, e.g. `jupyter {name}`.
-    name = None
+    name = "ExtensionApp"
 
     @classmethod
     def get_extension_package(cls):
@@ -318,7 +318,7 @@ def _prepare_handlers(self):
             handler = handler_items[1]
 
             # Get handler kwargs, if given
-            kwargs = {}
+            kwargs: dict = {}
             if issubclass(handler, ExtensionHandlerMixin):
                 kwargs["name"] = self.name