chore: 🔧 enforce type checking with ty (fixes #16)

AGENTS.md

@@ -62,6 +62,7 @@ uv run prek install --prepare-hooks
 uv run pytest -m "not slow"    # fast suite
 uv run pytest                  # everything
 uv run ruff check src/ tests/
+uv run ty check src/
 uv run mkdocs serve
 ```
 

CONTRIBUTING.md

@@ -38,11 +38,12 @@ replace them.
 ## Quality gates
 
 All of these must pass before a pull request can be merged;
-[`prek`](https://github.com/j178/prek) runs the first two automatically.
+[`prek`](https://github.com/j178/prek) runs the lint, format and type checks automatically.
 
 ```bash
 uv run ruff check src/ tests/       # lint
 uv run ruff format --check src/ tests/
+uv run ty check src/                # type check
 uv run pytest -m "not slow"         # fast test suite
 uv run pytest                       # full suite, including slow tests
 ```
@@ -63,6 +64,6 @@ accuracy, not just the shapes.
 ## Code style
 
 The project targets Python 3.11+ and is checked with `ruff` under a strict rule
-set. Public functions carry type hints and Google-style docstrings without type
+set and type-checked with [`ty`](https://github.com/astral-sh/ty). Public functions carry type hints and Google-style docstrings without type
 annotations in the argument list. Keep lines within the configured limit and
 prefer clear code over clever code.

prek.toml

@@ -40,3 +40,10 @@ hooks = [
 repo = "https://github.com/astral-sh/uv-pre-commit"
 rev = "0.8.14"
 hooks = [{ id = "uv-lock" }]
+
+
+[[repos]]
+# Keep in sync with the ty pin in pyproject.toml.
+repo = "https://github.com/astral-sh/ty-pre-commit"
+rev = "v0.0.82"
+hooks = [{ id = "ty" }]

pyproject.toml

@@ -71,6 +71,7 @@ dev = [
   "prek>=0.2.6",
   "ruff==0.16.5",
   "cyclopts>=3.20",
+  "ty==0.0.82",
   { include-group = "test" },
 ]
 interactive = [
@@ -269,25 +270,12 @@ convention = "google"
 required-imports = ["from __future__ import annotations"]
 
 
-[tool.pyright]
-pythonVersion = "3.11"
+[tool.ty.environment]
+python-version = "3.11"
 
-include = ["src/src_method/**/*.py"]
+[tool.ty.analysis]
+# Optional GPU dependency, imported lazily in `get_xp`.
+allowed-unresolved-imports = ["cupy"]
 
-exclude = ["test_*.py", "docs/**", "**/__pycache__"]
-
-typeCheckingMode = "basic"
-useLibraryCodeForTypes = true
-
-reportGeneralTypeIssues = "information"
-reportMissingImports = true
-reportMissingTypeStubs = "warning"
-reportImportCycles = "information"
-reportPrivateUsage = "information"
-reportPrivateImportUsage = "information"
-reportUnnecessaryIsInstance = "information"
-reportUnnecessaryCast = "information"
-reportUnnecessaryComparison = "information"
-reportUnnecessaryContains = "information"
-reportUnnecessaryTypeIgnoreComment = "information"
-reportMatchNotExhaustive = "information"
+[tool.ty.src]
+include = ["src/src_method"]

src/src_method/utils/linalg.py

@@ -12,7 +12,11 @@
     from numpy.typing import NDArray
 
 
-def truncated_qr(matrix: NDArray, cutoff: float, xp: ModuleType = np) -> NDArray:
+def truncated_qr(
+    matrix: NDArray[np.floating | np.complexfloating],
+    cutoff: float,
+    xp: ModuleType = np,
+) -> NDArray[np.floating | np.complexfloating]:
     """QR with SVD-based rank truncation, returning only the isometry.
 
     Decomposes ``matrix = Q @ R``, then truncates via SVD on R,

src/src_method/utils/logging_config.py

@@ -25,9 +25,8 @@ def setup_logging(default_level: str = "INFO") -> None:
     """
     # Configure Python's standard logging
     level_name = os.environ.get("LOG_LEVEL_SRC", default_level)
-    level = logging.getLevelName(level_name.upper())
     logging.basicConfig(
-        level=level,
+        level=level_name.upper(),
         format="%(message)s",
         stream=sys.stdout,
     )