Tech Debt - Add Type Checking

.github/workflows/ci.yml

@@ -30,6 +30,9 @@ jobs:
       - name: Install dependencies
         run: uv sync
 
+      - name: Type check with ty
+        run: uv run ty check
+
       - name: Check line length violations with ruff
         run: uv run ruff check --select=E501 --exit-zero
 

.vscode/extensions.json

@@ -0,0 +1,3 @@
+{
+    "recommendations": ["astral-sh.ty", "charliermarsh.ruff"]
+}

.vscode/settings.json

@@ -2,7 +2,7 @@
     "[python]": {
         "editor.defaultFormatter": "charliermarsh.ruff"
     },
-    "python.testing.unittestEnabled": false,
+    "python.languageServer": "None",
     "python.testing.pytestEnabled": true,
     "python.testing.pytestArgs": ["tests"]
 }

.zed/settings.json

@@ -0,0 +1,7 @@
+{
+    "languages": {
+        "Python": {
+            "language_servers": ["ty", "ruff"]
+        }
+    }
+}

docs/conf.py

@@ -1,4 +1,4 @@
-import tomllib
+import tomllib  # ty: ignore[unresolved-import]
 
 # Configuration file for the Sphinx documentation builder.
 #

docs/requirements.txt

@@ -55,7 +55,7 @@ sphinx==9.1.0 ; python_full_version >= '3.12'
     #   python-docs-theme
     #   sphinx-autoapi
     #   sphinx-autobuild
-sphinx-autoapi==3.8.0 ; python_full_version >= '3.12'
+sphinx-autoapi==3.8.1 ; python_full_version >= '3.12'
 sphinx-autobuild==2025.8.25 ; python_full_version >= '3.12'
 sphinxcontrib-applehelp==2.0.0 ; python_full_version >= '3.12'
     # via sphinx

pyproject.toml

@@ -38,6 +38,7 @@ Repository = "https://github.com/iskandergaba/free-threading"
 
 [dependency-groups]
 dev = [
+    "ty~=0.0.70",
     "ruff~=0.16.0",
     "pytest~=9.1.0",
     "pytest-cov~=7.1.0",

src/freethreading/__init__.py

@@ -127,21 +127,24 @@ def _get_mp_context():
     from threading import Semaphore as _Semaphore
     from threading import Thread as _Worker
     from threading import active_count as _active_count
-    from threading import current_thread as _current_worker
+    from threading import current_thread
     from threading import enumerate as _enumerate
     from threading import get_ident as _get_ident
 
+    _current_worker = current_thread
+
     def _active_children():
         children = list(_enumerate())
-        children.remove(_current_worker())
+        children.remove(current_thread())
         return children
 
 else:
     from concurrent.futures import ProcessPoolExecutor as _WorkerPoolExecutor
     from multiprocessing import active_children as _active_children
-    from multiprocessing import current_process as _current_worker
+    from multiprocessing import current_process
     from os import getpid as _get_ident
 
+    _current_worker = current_process
     _Barrier = _get_mp_context().Barrier
     _BoundedSemaphore = _get_mp_context().BoundedSemaphore
     _Condition = _get_mp_context().Condition
@@ -159,7 +162,7 @@ def _active_count():
 
     def _enumerate():
         workers = list(_active_children())
-        workers.append(_current_worker())
+        workers.append(current_process())
         return workers
 
 
@@ -434,7 +437,7 @@ def consumer(condition, queue):
 
     def __init__(self, lock=None):
         self._condition = _Condition(
-            lock._lock if isinstance(lock, (Lock, RLock)) else None  # type: ignore[arg-type]
+            lock._lock if isinstance(lock, (Lock, RLock)) else None
         )
 
     def __reduce__(self):
@@ -458,13 +461,9 @@ def acquire(self, blocking=True, timeout=None):
         bool
             True if acquired, False if not acquired (non-blocking or timeout).
         """
-        if get_backend() == "threading":
-            if timeout is None or timeout < 0:
-                timeout = -1
-        else:
-            if timeout is not None and timeout < 0:
-                timeout = None
-        return self._condition.acquire(blocking, timeout)  # type: ignore[call-arg]
+        if timeout is None or timeout < 0:
+            return self._condition.acquire(blocking)
+        return self._condition.acquire(blocking, timeout)
 
     def release(self):
         """
@@ -725,13 +724,9 @@ def acquire(self, blocking=True, timeout=None):
         bool
             True if acquired, False if not acquired (non-blocking or timeout).
         """
-        if get_backend() == "threading":
-            if timeout is None or timeout < 0:
-                timeout = -1
-        else:
-            if timeout is not None and timeout < 0:
-                timeout = None
-        return self._lock.acquire(blocking, timeout)  # type: ignore[call-arg]
+        if timeout is None or timeout < 0:
+            return self._lock.acquire(blocking)
+        return self._lock.acquire(blocking, timeout)
 
     def release(self):
         """
@@ -756,7 +751,7 @@ def locked(self):
             True if locked, False otherwise.
         """
         if hasattr(self._lock, "locked"):
-            return self._lock.locked()  # type: ignore[attr-defined]
+            return self._lock.locked()
 
         # Fallback for Python < 3.14
         if self.acquire(blocking=False):
@@ -1042,13 +1037,9 @@ def acquire(self, blocking=True, timeout=None):
         bool
             True if acquired, False if not acquired (non-blocking or timeout).
         """
-        if get_backend() == "threading":
-            if timeout is None or timeout < 0:
-                timeout = -1
-        else:
-            if timeout is not None and timeout < 0:
-                timeout = None
-        return self._lock.acquire(blocking, timeout)  # type: ignore[call-arg]
+        if timeout is None or timeout < 0:
+            return self._lock.acquire(blocking)
+        return self._lock.acquire(blocking, timeout)
 
     def release(self):
         """
@@ -1865,7 +1856,7 @@ def _raise_unpickle_type_error():
 def _validate_picklability(**kwargs):
     """Validate that all arguments are picklable for multiprocessing compatibility."""
     spawning_popen = get_spawning_popen()
-    set_spawning_popen(_DummyPopen)  # type: ignore[arg-type]
+    set_spawning_popen(_DummyPopen)  # ty: ignore[invalid-argument-type]
     try:
         dump(tuple(kwargs.values()), io.BytesIO())
     except (AttributeError, TypeError, pickle.PicklingError) as e:

tests/test_freethreading.py

@@ -110,13 +110,22 @@ def test_condition_with_rlock(backend):
 def test_condition_acquire_release(backend):
     cond = backend.Condition()
     acquired = cond.acquire()
-    assert acquired is True
+    assert acquired
+    cond.release()
+
+
+def test_condition_acquire_timeout(backend):
+    cond = backend.Condition()
+
+    acquired = cond.acquire(timeout=0.01)
+    assert acquired
+
     cond.release()
 
 
 def test_condition_acquire_negative_timeout(backend):
     cond = backend.Condition()
-    result = cond.acquire(blocking=True, timeout=-0.5)
+    result = cond.acquire(blocking=True, timeout=-1)
     assert result
     cond.release()
 
@@ -144,7 +153,7 @@ def test_condition_wait(backend):
     cond = backend.Condition()
     with cond:
         notified = cond.wait(timeout=0.01)
-    assert notified is False
+    assert not notified
 
 
 def test_condition_wait_for(backend):
@@ -225,8 +234,8 @@ def test_lock_acquire_timeout(backend):
     acquired = lock.acquire(timeout=0.01)
     assert acquired
 
-    acquired2 = lock.acquire(blocking=False)
-    assert not acquired2
+    acquired = lock.acquire(blocking=False)
+    assert not acquired
 
     lock.release()
 
@@ -348,9 +357,18 @@ def test_rlock_acquire_release(backend):
     lock.release()
 
 
+def test_rlock_acquire_timeout(backend):
+    lock = backend.RLock()
+
+    acquired = lock.acquire(timeout=0.01)
+    assert acquired
+
+    lock.release()
+
+
 def test_rlock_acquire_negative_timeout(backend):
     lock = backend.RLock()
-    result = lock.acquire(blocking=True, timeout=-0.5)
+    result = lock.acquire(blocking=True, timeout=-1)
     assert result
     lock.release()
 
@@ -383,8 +401,8 @@ def test_semaphore_timeout(backend):
     acquired = sem.acquire(timeout=0.01)
     assert acquired
 
-    acquired2 = sem.acquire(blocking=False)
-    assert not acquired2
+    acquired = sem.acquire(blocking=False)
+    assert not acquired
 
     sem.release()
 
@@ -436,10 +454,10 @@ def test_worker_name_property(backend):
 
 def test_worker_daemon_property(backend):
     worker = backend.Worker(target=task, daemon=False)
-    assert worker.daemon is False
+    assert not worker.daemon
 
     worker.daemon = True
-    assert worker.daemon is True
+    assert worker.daemon
 
     worker.start()
     worker.join()