Add ty type checker

Add ty configuration. ty provides fast type checking that complements
pyright/mypy, while ruff handles missing type hints detection.

ty is not yet reporting as much problems as mypy or pyright, but it is
much, much faster, and is already interesting to use interactively.

This change only aims at making ty usable in this project, without
replacing mypy or pyright. As such it is not added in the dev dependencies
and must be installed manually, for example with

  uv tool install ty

Signed-off-by: Gaëtan Lehmann <gaetan.lehmann@vates.tech>

Author: glehmann

.pre-commit-config.yaml

@@ -33,6 +33,15 @@ repos:
         require_serial: true
         entry: "uv run flake8"
         types: ["python"]
+      - id: "ty"
+        name: "ty"
+        language: "system"
+        require_serial: true
+        entry: "uv run ty check ."
+        types: ["python"]
+        stages: ["manual"]
+        pass_filenames: false
+        always_run: true
       - id: "mypy"
         name: "mypy"
         language: "system"

Makefile

@@ -1,7 +1,7 @@
 # Makefile to run static code checkers locally
 # Equivalent to the GitHub Actions workflow in .github/workflows/code-checkers.yml
 
-.PHONY: all mypy pyright ruff ruff-fix flake8 autopep8 autopep8-fix
+.PHONY: all mypy pyright ruff ruff-fix flake8 autopep8 autopep8-fix ty
 
 # By default, only run the non-fix version of the hooks so it doesn't modify any files
 # It runs on all files managed by git (untracked files are not checked)
@@ -19,5 +19,5 @@ vm_data.py:
 
 mypy pyright ruff: data.py vm_data.py
 
-ruff ruff-fix autopep8 autopep8-fix flake8 mypy pyright:
+ruff ruff-fix autopep8 autopep8-fix flake8 ty mypy pyright:
 	uv run prek -a $@

conftest.py

@@ -280,6 +280,7 @@ def pytest_runtest_makereport(
 
     # store test results for each phase of a call, which can
     # be "setup", "call", "teardown"
+    assert rep.when is not None
     item.stash.setdefault(PHASE_REPORT_KEY, {})[rep.when] = rep
 
     return rep

data.py-dist

@@ -171,7 +171,7 @@ ISO_IMAGES: dict[str, "IsoImageDef"] = {
 # - 'default': keep using the pool's default SR
 # - 'local': use the first local SR found instead
 # - A UUID of the SR to be used
-DEFAULT_SR = 'default'
+DEFAULT_SR: str = 'default'
 
 # Whether to cache VMs on the test host, that is import them only if not already
 # present in the target SR. This also causes the VM to be cloned at the beginning
@@ -182,7 +182,7 @@ DEFAULT_SR = 'default'
 # Example description: "[Cache for http://example.com/images/filename.xva]"
 # Delete the VM to remove it from cache.
 # This setting affects VMs managed by the `imported_vm` fixture.
-CACHE_IMPORTED_VM = False
+CACHE_IMPORTED_VM: bool = False
 
 # Default LINSTOR redundancy configuration for creating SRs.
 LINSTOR_REDUNDANCY = 2

lib/config.py

@@ -1,10 +1,10 @@
 from lib.common import GiB
 
-ignore_ssh_banner = False
-ssh_output_max_lines = 20
-volume_size = 1 * GiB
-write_volume_cap = 2 * GiB
-write_volume_align = 1
+ignore_ssh_banner: bool = False
+ssh_output_max_lines: int = 20
+volume_size: int = 1 * GiB
+write_volume_cap: int = 2 * GiB
+write_volume_align: int = 1
 
 def sr_device_config(datakey: str, *, required: list[str] = []) -> dict[str, str]:
     import data  # import here to avoid depending on this user file for collecting tests

pyproject.toml

@@ -21,23 +21,23 @@ dependencies = [
 
 [dependency-groups]
 dev = [
+    "autopep8",
     "bs4>=0.0.1",
-    "mypy",
     "flake8",
     "flake8-pyproject",
+    "libarchive-c==5.3",
+    "mypy",
+    "prek",
     "pydocstyle",
     "pyright",
     "ruff",
-    "types-requests",
-    "typing-extensions",
-    "libarchive-c==5.3",
-    "types-pygments",
     "types-colorama",
+    "types-passlib",
     "types-pexpect",
+    "types-pygments",
+    "types-requests",
+    "typing-extensions",
     "zizmor",
-    "prek",
-    "autopep8",
-    "types-passlib",
 ]
 
 [tool.mypy]
@@ -55,6 +55,9 @@ typeCheckingMode = "standard"
 reportMissingParameterType = "error"
 reportUnknownParameterType = "error"
 
+[tool.ty.rules]
+unused-type-ignore-comment = "ignore"
+
 [tool.ruff]
 preview = true
 line-length = 120
@@ -65,6 +68,7 @@ quote-style = "preserve"
 
 [tool.ruff.lint]
 select = [
+  "ANN",  # flake8-annotations
   "D",  # pydocstyle
   "FA",  # future-annotations
   "F",  # Pyflakes
@@ -78,6 +82,7 @@ select = [
 ]
 # don't use some of the default D and SIM rules
 ignore = [
+  "ANN401",  # missing-return-type-special-method. Might be removed later.
   "D100",  # undocumented-public-module
   "D101",  # undocumented-public-class
   "D102",  # undocumented-public-method
@@ -98,6 +103,7 @@ ignore = [
   "SIM105",  # suppressible-exception
   "SIM108",  # if-else-block-instead-of-if-exp
 ]
+flake8-annotations.mypy-init-return = true
 
 # restrict to the PEP 257 rules
 pydocstyle.convention = "pep257"

requirements/dev.txt

@@ -1,19 +1,19 @@
 # generated with update_requirements.py, do not edit manually
+autopep8
 bs4>=0.0.1
-mypy
 flake8
 flake8-pyproject
+libarchive-c==5.3
+mypy
+prek
 pydocstyle
 pyright
 ruff
-types-requests
-typing-extensions
-libarchive-c==5.3
-types-pygments
 types-colorama
+types-passlib
 types-pexpect
+types-pygments
+types-requests
+typing-extensions
 zizmor
-prek
-autopep8
-types-passlib
 -r base.txt