Add basic mypy support

Author: blink1073

.pre-commit-config.yaml

@@ -41,6 +41,15 @@ repos:
         args: [--max-line-length=200]
         stages: [manual]
 
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v0.942
+    hooks:
+      - id: mypy
+        exclude: 'ipykernel.*tests'
+        args: ["--config-file", "pyproject.toml"]
+        additional_dependencies: [tornado, jupyter_client, pytest]
+        stages: [manual]
+
   - repo: https://github.com/pycqa/flake8
     rev: 4.0.1
     hooks:

MANIFEST.in

@@ -1,5 +1,6 @@
 include *.md
 include pyproject.toml
+include ipykernel/py.typed
 
 # Documentation
 graft docs

docs/conf.py

@@ -61,7 +61,7 @@
 # built documents.
 #
 
-version_ns = {}
+version_ns: dict = {}
 here = os.path.dirname(__file__)
 version_py = os.path.join(here, os.pardir, "ipykernel", "_version.py")
 with open(version_py) as f:
@@ -150,7 +150,7 @@
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = []
+html_static_path: list = []
 
 # Add any extra paths that contain custom files (such as robots.txt or
 # .htaccess) here, relative to this directory. These files are copied
@@ -217,7 +217,7 @@
 
 # -- Options for LaTeX output ---------------------------------------------
 
-latex_elements = {}
+latex_elements: dict = {}
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title,

ipykernel/_eventloop_macos.py

@@ -10,7 +10,7 @@
 import ctypes.util
 from threading import Event
 
-objc = ctypes.cdll.LoadLibrary(ctypes.util.find_library("objc"))
+objc = ctypes.cdll.LoadLibrary(ctypes.util.find_library("objc"))  # type:ignore[arg-type]
 
 void_p = ctypes.c_void_p
 
@@ -42,7 +42,7 @@ def C(classname):
 # end obj-c boilerplate from appnope
 
 # CoreFoundation C-API calls we will use:
-CoreFoundation = ctypes.cdll.LoadLibrary(ctypes.util.find_library("CoreFoundation"))
+CoreFoundation = ctypes.cdll.LoadLibrary(ctypes.util.find_library("CoreFoundation"))  # type:ignore[arg-type]
 
 CFAbsoluteTimeGetCurrent = CoreFoundation.CFAbsoluteTimeGetCurrent
 CFAbsoluteTimeGetCurrent.restype = ctypes.c_double

ipykernel/_version.py

@@ -9,7 +9,8 @@
 # Build up version_info tuple for backwards compatibility
 pattern = r"(?P<major>\d+).(?P<minor>\d+).(?P<patch>\d+)(?P<rest>.*)"
 match = re.match(pattern, __version__)
-parts = [int(match[part]) for part in ["major", "minor", "patch"]]
+assert match is not None
+parts: list = [int(match[part]) for part in ["major", "minor", "patch"]]
 if match["rest"]:
     parts.append(match["rest"])
 version_info = tuple(parts)

ipykernel/connect.py

@@ -6,6 +6,7 @@
 import json
 import sys
 from subprocess import PIPE, Popen
+from typing import Any
 
 import jupyter_client
 from jupyter_client import write_connection_file
@@ -68,13 +69,15 @@ def get_connection_info(connection_file=None, unpack=False):
     cf = _find_connection_file(connection_file)
 
     with open(cf) as f:
-        info = f.read()
+        info_str = f.read()
 
     if unpack:
-        info = json.loads(info)
+        info = json.loads(info_str)
         # ensure key is bytes:
         info["key"] = info.get("key", "").encode()
-    return info
+        return info
+
+    return info_str
 
 
 def connect_qtconsole(connection_file=None, argv=None):
@@ -105,7 +108,7 @@ def connect_qtconsole(connection_file=None, argv=None):
 
     cmd = ";".join(["from IPython.qt.console import qtconsoleapp", "qtconsoleapp.main()"])
 
-    kwargs = {}
+    kwargs: dict[str, Any] = {}
     # Launch the Qt console in a separate session & process group, so
     # interrupting the kernel doesn't kill it.
     kwargs["start_new_session"] = True

ipykernel/debugger.py

@@ -1,6 +1,7 @@
 import os
 import re
 import sys
+import typing as t
 
 import zmq
 from IPython.core.getipython import get_ipython
@@ -89,7 +90,7 @@ def __init__(self, event_callback, log):
         self.tcp_buffer = ""
         self._reset_tcp_pos()
         self.event_callback = event_callback
-        self.message_queue = Queue()
+        self.message_queue: Queue = Queue()
         self.log = log
 
     def _reset_tcp_pos(self):
@@ -100,7 +101,7 @@ def _reset_tcp_pos(self):
 
     def _put_message(self, raw_msg):
         self.log.debug("QUEUE - _put_message:")
-        msg = jsonapi.loads(raw_msg)
+        msg = t.cast(dict, jsonapi.loads(raw_msg))
         if msg["type"] == "event":
             self.log.debug("QUEUE - received event:")
             self.log.debug(msg)
@@ -290,7 +291,7 @@ def __init__(
         self.is_started = False
         self.event_callback = event_callback
         self.just_my_code = just_my_code
-        self.stopped_queue = Queue()
+        self.stopped_queue: Queue = Queue()
 
         self.started_debug_handlers = {}
         for msg_type in Debugger.started_debug_msg_types:

ipykernel/displayhook.py

@@ -32,7 +32,7 @@ def __call__(self, obj):
         if obj is None:
             return
 
-        builtins._ = obj
+        builtins._ = obj  # type:ignore[attr-defined]
         sys.stdout.flush()
         sys.stderr.flush()
         contents = {

ipykernel/eventloops.py

@@ -248,7 +248,7 @@ def process_stream_events(stream, *a, **kw):
 
         notifier = partial(process_stream_events, kernel.shell_stream)
         # seems to be needed for tk
-        notifier.__name__ = "notifier"
+        notifier.__name__ = "notifier"  # type:ignore[attr-defined]
         app.tk.createfilehandler(kernel.shell_stream.getsockopt(zmq.FD), READABLE, notifier)
         # schedule initial call after start
         app.after(0, notifier)
@@ -386,7 +386,7 @@ def loop_asyncio(kernel):
         # main loop is closed, create a new one
         loop = asyncio.new_event_loop()
         asyncio.set_event_loop(loop)
-    loop._should_close = False
+    loop._should_close = False  # type:ignore[attr-defined]
 
     # pause eventloop when there's an event on a zmq socket
     def process_stream_events(stream):
@@ -406,7 +406,7 @@ def process_stream_events(stream):
             continue
         except Exception as e:
             error = e
-        if loop._should_close:
+        if loop._should_close:  # type:ignore[attr-defined]
             loop.close()
         if error is not None:
             raise error
@@ -424,14 +424,14 @@ def loop_asyncio_exit(kernel):
     def close_loop():
         if hasattr(loop, "shutdown_asyncgens"):
             yield from loop.shutdown_asyncgens()
-        loop._should_close = True
+        loop._should_close = True  # type:ignore[attr-defined]
         loop.stop()
 
     if loop.is_running():
         close_loop()
 
     elif not loop.is_closed():
-        loop.run_until_complete(close_loop)
+        loop.run_until_complete(close_loop)  # type:ignore[call-overload]
         loop.close()
 
 

ipykernel/gui/gtk3embed.py

@@ -14,11 +14,11 @@
 import sys
 
 # Third-party
-import gi
+import gi  # type:ignore[import]
 
 gi.require_version("Gdk", "3.0")
 gi.require_version("Gtk", "3.0")
-from gi.repository import GObject, Gtk
+from gi.repository import GObject, Gtk  # type:ignore[import]
 
 # -----------------------------------------------------------------------------
 # Classes and functions
@@ -63,7 +63,8 @@ def stop(self):
         # FIXME: this one isn't getting called because we have no reliable
         # kernel shutdown.  We need to fix that: once the kernel has a
         # shutdown mechanism, it can call this.
-        self.gtk_main_quit()
+        if self.gtk_main_quit:
+            self.gtk_main_quit()
         sys.exit()
 
     def _hijack_gtk(self):