98 switch from mypy to ty

.gitignore

@@ -3,4 +3,5 @@
 .idea
 .coverage
 .claude
+.devcontainer
 *.pyc

AGENTS.md

@@ -46,7 +46,7 @@ Read that file for the full list.  The most important ones for day-to-day work a
 | `make test` | Runs the full pipeline: unit tests, feature tests, style, type checks, security. Run this before marking work complete. |
 | `make format` | Formats all Python files with Ruff. Run this before committing. |
 | `make lint` | Lints with safe fixes. |
-| `make type_checks` | Runs mypy across all packages. |
+| `make type_checks` | Runs ty type checks across all packages. |
 | `make uv_lock` | Updates `uv.lock` in the dev container after changing dependencies. |
 | `make test_pypi` | Runs unit and feature tests for `pypi_package` only. Faster than `make test`. |
 | `make test_build_support` | Runs unit and feature tests for `build_support` only. |

Makefile

@@ -190,6 +190,9 @@ setup_prod_env: setup_build_env
 setup_pulumi_env: setup_build_env
 	$(EXECUTE_BUILD_STEPS_COMMAND) setup_pulumi_env
 
+# Suppress initial docker build output unless LOG_LEVEL is TRACE
+DOCKER_BUILD_QUIET = $(if $(filter TRACE,$(LOG_LEVEL)), , > /dev/null 2>&1)
+
 .PHONY: setup_build_env
 setup_build_env:
 ifeq ($(CI_CD_FEATURE_TEST_MODE_FLAG), )
@@ -202,7 +205,7 @@ ifeq ($(CI_CD_FEATURE_TEST_MODE_FLAG), )
 -f $(DOCKERFILE) \
 --target build \
 --build-arg BUILDKIT_INLINE_CACHE=1 \
--t $(DOCKER_BUILD_IMAGE) $(MAKEFILE_DIR)
+-t $(DOCKER_BUILD_IMAGE) $(MAKEFILE_DIR)$(DOCKER_BUILD_QUIET)
 else
 	echo "Skipping building build docker image in CI/CD mode."
 endif

build_support/src/build_support/ci_cd_tasks/env_setup_tasks.py

@@ -152,15 +152,18 @@ def run(self) -> None:
                 get_feature_test_scratch_folder(project_root=self.docker_project_root),
             ]
         )
-        run_process(
-            args=["rm", "-rf", self.docker_project_root.joinpath(".mypy_cache")]
-        )
+        run_process(args=["rm", "-rf", self.docker_project_root.joinpath(".ty_cache")])
         run_process(
             args=["rm", "-rf", self.docker_project_root.joinpath(".pytest_cache")]
         )
         run_process(
             args=["rm", "-rf", self.docker_project_root.joinpath(".ruff_cache")]
         )
+        run_process(
+            args=["rm", "-rf", str(self.docker_project_root.joinpath(".coverage"))]
+        )
+        for path in self.docker_project_root.glob(".coverage.*"):
+            run_process(args=["rm", "-rf", str(path)])
 
 
 class GitInfo(BaseModel):

build_support/src/build_support/ci_cd_tasks/validation_tasks.py

@@ -9,7 +9,7 @@
 from copy import deepcopy
 from dataclasses import dataclass
 from pathlib import Path
-from typing import override
+from typing import cast, override
 
 from junitparser import JUnitXml
 from tomlkit import TOMLDocument, document, dumps, table
@@ -27,7 +27,7 @@
     get_base_docker_command_for_image,
     get_docker_command_for_image,
     get_docker_image_name,
-    get_mypy_path_env,
+    get_ty_extra_search_path_args,
 )
 from build_support.ci_cd_vars.file_and_dir_path_vars import (
     get_all_non_test_folders,
@@ -184,17 +184,16 @@ def run(self) -> None:
                         docker_project_root=self.docker_project_root,
                         target_image=DockerTarget.DEV,
                     ),
-                    "-e",
-                    get_mypy_path_env(
-                        docker_project_root=self.docker_project_root,
-                        target_image=DockerTarget.DEV,
-                    ),
                     get_docker_image_name(
                         project_root=self.docker_project_root,
                         target_image=DockerTarget.DEV,
                     ),
-                    "mypy",
-                    "--explicit-package-bases",
+                    "ty",
+                    "check",
+                    get_ty_extra_search_path_args(
+                        docker_project_root=self.docker_project_root,
+                        target_image=DockerTarget.DEV,
+                    ),
                     self.subproject.get_root_dir(),
                 ]
             )
@@ -414,7 +413,8 @@ def get_coverage_settings(self) -> TOMLDocument:
                 TOMLDocument.
         """
         pyproject_data = get_pyproject_toml_data(project_root=self.docker_project_root)
-        return pyproject_data["tool"]["coverage"]  # type: ignore[index, return-value]
+        tool = cast(TOMLDocument, pyproject_data["tool"])
+        return cast(TOMLDocument, tool["coverage"])
 
     def build_omit_list(self, unit_test_info: UnitTestInfo) -> list[str]:
         """Builds the list of omit patterns for a coverage config file.
@@ -475,11 +475,10 @@ def write_coverage_config_file(
         coverage_config = deepcopy(coverage_settings)
         if "run" not in coverage_config:
             coverage_config["run"] = table()
-        existing_omit = coverage_config["run"].get(  # type: ignore[union-attr]
-            "omit", []
-        )
+        run_table = cast(TOMLDocument, coverage_config["run"])
+        existing_omit = run_table.get("omit", [])
         merged_omit = list(dict.fromkeys(list(existing_omit) + new_omit_list))
-        coverage_config["run"]["omit"] = merged_omit  # type: ignore[index]
+        run_table["omit"] = merged_omit
 
         # Write TOML file
         config_doc = document()

build_support/src/build_support/ci_cd_vars/docker_vars.py

@@ -3,7 +3,7 @@
 from enum import StrEnum
 from os import environ
 from pathlib import Path
-from typing import Any
+from typing import Any, cast
 
 from build_support.ci_cd_vars.file_and_dir_path_vars import (
     get_all_python_folders,
@@ -118,23 +118,23 @@ def get_python_path_env(docker_project_root: Path, target_image: DockerTarget) -
     )
 
 
-def get_mypy_path_for_target_image(
+def get_ty_extra_search_paths_for_target_image(
     docker_project_root: Path, target_image: DockerTarget
-) -> str:
-    """Gets the mypy path to use with this project.
+) -> list[Path]:
+    """Gets ty extra search paths for this project.
 
     Args:
         docker_project_root (Path): Path to this project's root when running in docker
             containers.
         target_image (DockerTarget): An enum specifying which type of docker image we
-            are requesting the mypy path for.
+            are requesting extra search paths for.
 
     Returns:
-        str: The MYPYPATH for the specified docker image.
+        list[Path]: Extra search paths for ty for the specified docker image.
     """
     match target_image:
         case DockerTarget.BUILD:
-            python_folders = [
+            search_paths = [
                 get_python_subproject(
                     subproject_context=SubprojectContext.BUILD_SUPPORT,
                     project_root=docker_project_root,
@@ -143,16 +143,16 @@ def get_mypy_path_for_target_image(
         case DockerTarget.DEV:
             src_folders = get_all_src_folders(project_root=docker_project_root)
             test_folders = get_all_test_folders(project_root=docker_project_root)
-            python_folders = src_folders + test_folders
+            search_paths = src_folders + test_folders
         case DockerTarget.PROD:
-            python_folders = [
+            search_paths = [
                 get_python_subproject(
                     subproject_context=SubprojectContext.PYPI,
                     project_root=docker_project_root,
                 ).get_src_dir()
             ]
         case DockerTarget.INFRA:
-            python_folders = [
+            search_paths = [
                 get_python_subproject(
                     subproject_context=SubprojectContext.INFRA,
                     project_root=docker_project_root,
@@ -161,25 +161,29 @@ def get_mypy_path_for_target_image(
         case _:  # pragma: no cov - can't hit if all enums are implemented
             msg = f"{target_image!r} is not a valid enum of DockerType."
             raise ValueError(msg)
-    return ":".join(concatenate_args(args=[python_folders]))
+    return search_paths
 
 
-def get_mypy_path_env(docker_project_root: Path, target_image: DockerTarget) -> str:
-    """Gets the mypy path ENV to use with this project.
+def get_ty_extra_search_path_args(
+    docker_project_root: Path, target_image: DockerTarget
+) -> list[str]:
+    """Gets CLI args for ty extra search paths.
 
     Args:
         docker_project_root (Path): Path to this project's root when running in docker
             containers.
         target_image (DockerTarget): An enum specifying which type of docker image we
-            are requesting the mypy path for.
+            are requesting extra search path args for.
 
     Returns:
-        str: The MYPYPATH for the specified docker image in the form on an ENV variable
-            that can be used on the command line.
+        list[str]: Flattened ``--extra-search-path`` arguments for ty.
     """
-    return "MYPYPATH=" + get_mypy_path_for_target_image(
+    extra_search_args: list[str] = []
+    for search_path in get_ty_extra_search_paths_for_target_image(
         docker_project_root=docker_project_root, target_image=target_image
-    )
+    ):
+        extra_search_args.extend(["--extra-search-path", str(search_path)])
+    return concatenate_args(args=cast(list[Any | list[Any]], extra_search_args))
 
 
 def get_base_docker_command_for_image(

build_support/src/build_support/ci_cd_vars/file_and_dir_path_vars.py

@@ -76,7 +76,7 @@ def get_test_utils_dirs(project_root: Path) -> list[Path]:
 
     The test_utils folder contains utility Python source files that are used by
     test files but are not test files themselves. These directories need to be in
-    MYPYPATH so mypy can resolve imports from test files.
+    ty extra search paths so imports from test files can be resolved.
 
     Args:
         project_root (Path): Path to this project's root.

build_support/src/build_support/ci_cd_vars/project_setting_vars.py

@@ -7,6 +7,7 @@
 import re
 import tomllib
 from pathlib import Path
+from typing import cast
 
 from tomlkit import TOMLDocument, parse
 
@@ -46,7 +47,7 @@ def get_project_version(project_root: Path) -> str:
     """
     pyproject_data = get_pyproject_toml_data(project_root=project_root)
     version_str: str
-    version_str = str(pyproject_data["project"]["version"])  # type: ignore[index]
+    version_str = str(cast(TOMLDocument, pyproject_data["project"])["version"])
     if not ALLOWED_VERSION_REGEX.match(version_str):
         msg = (
             "Project version in pyproject.toml must match the regex "
@@ -90,7 +91,7 @@ def get_project_name(project_root: Path) -> str:
         str: The name of the project.
     """
     pyproject_data = get_pyproject_toml_data(project_root=project_root)
-    return str(pyproject_data["project"]["name"])  # type: ignore[index]
+    return str(cast(TOMLDocument, pyproject_data["project"])["name"])
 
 
 ########################################

build_support/src/build_support/ci_cd_vars/project_structure.py

@@ -86,18 +86,18 @@ def get_feature_test_scratch_folder(project_root: Path) -> Path:
     return maybe_build_dir(dir_to_build=project_root.joinpath("test_scratch_folder"))
 
 
-def get_feature_test_log_name(project_root: Path, test_name: str) -> Path:
+def get_feature_test_log_file(project_root: Path, log_name: str) -> Path:
     """Gets the path to a log file for a feature test.
 
     Args:
         project_root (Path): Path to this project's root.
-        test_name (str): Name of the test (will be sanitized for filename).
+        log_name (str): Name of the test (will be sanitized for filename).
 
     Returns:
         Path: Path to the log file for the test in test_scratch_folder/test_logs/.
     """
     # Sanitize test name for use as filename
-    safe_test_name = test_name.replace("[", "_").replace("]", "_").replace("::", "_")
+    safe_test_name = log_name.replace("[", "_").replace("]", "_").replace("::", "_")
     # Remove trailing underscores that may result from sanitization
     safe_test_name = safe_test_name.rstrip("_")
     log_dir = maybe_build_dir(

build_support/src/build_support/new_project_setup/update_pyproject_toml.py

@@ -1,6 +1,7 @@
 """Module exists to conceptually organize all changes to the pyproject.toml file."""
 
 from pathlib import Path
+from typing import cast
 
 from tomlkit import TOMLDocument, dumps
 
@@ -24,15 +25,15 @@ def update_pyproject_toml(
     """
     path_to_pyproject_toml = get_pyproject_toml(project_root=project_root)
     pyproject_data: TOMLDocument = get_pyproject_toml_data(project_root=project_root)
-    project = pyproject_data["project"]
-    project["name"] = new_project_settings.name  # type: ignore[index]
-    project["version"] = "0.0.0"  # type: ignore[index]
-    project["license"] = new_project_settings.license  # type: ignore[index]
-    project["authors"] = [  # type: ignore[index]
-        new_project_settings.organization.as_pyproject_author()
-    ]
-    hatch = pyproject_data["tool"]["hatch"]  # type: ignore[index]
-    hatch["build"]["targets"]["wheel"]["packages"] = [  # type: ignore[index]
-        f"pypi_package/src/{new_project_settings.name}"
-    ]
+    project = cast(TOMLDocument, pyproject_data["project"])
+    project["name"] = new_project_settings.name
+    project["version"] = "0.0.0"
+    project["license"] = new_project_settings.license
+    project["authors"] = [new_project_settings.organization.as_pyproject_author()]
+    tool = cast(TOMLDocument, pyproject_data["tool"])
+    hatch = cast(TOMLDocument, tool["hatch"])
+    hatch_build = cast(TOMLDocument, hatch["build"])
+    targets = cast(TOMLDocument, hatch_build["targets"])
+    wheel = cast(TOMLDocument, targets["wheel"])
+    wheel["packages"] = [f"pypi_package/src/{new_project_settings.name}"]
     path_to_pyproject_toml.write_text(dumps(pyproject_data))

build_support/test/feature_tests/conftest.py

@@ -30,6 +30,7 @@
     get_python_subproject,
 )
 from git import Head, Repo
+from test_utils.command_runner import FeatureTestCommandContext
 
 
 def remove_dir_and_all_contents(path: Path) -> None:
@@ -114,6 +115,27 @@ def make_command_prefix(make_command_prefix_without_tag_suffix: list[str]) -> li
     return [*make_command_prefix_without_tag_suffix, f"TAG_SUFFIX={tag_suffix}"]
 
 
+@pytest.fixture
+def default_command_context(
+    mock_project_root: Path,
+    make_command_prefix: list[str],
+    real_project_root_dir: Path,
+    request: SubRequest,
+) -> FeatureTestCommandContext:
+    """Default feature test context for run_command_and_save_logs.
+
+    Tests call run_command_and_save_logs(context=..., command_args=...). Copy and
+    override fields when needed (e.g. expect_failure, log_name, args_prefix).
+    """
+    return FeatureTestCommandContext(
+        args_prefix=make_command_prefix,
+        mock_project_root=mock_project_root,
+        real_project_root_dir=real_project_root_dir,
+        test_name=request.node.name,
+        log_name=request.node.name,
+    )
+
+
 @pytest.fixture(scope="session")
 def mock_lightweight_project_copy_dir(real_build_dir: Path) -> Path:
     """Return the directory path for the lightweight project cache.
@@ -347,7 +369,9 @@ def mock_lightweight_project_with_unit_tests_and_feature_tests(
         Repo: The updated mock project repository.
     """
     for subproject in [
-        get_python_subproject(SubprojectContext.PYPI, mock_project_root)
+        get_python_subproject(
+            subproject_context=SubprojectContext.PYPI, project_root=mock_project_root
+        )
     ]:
         subproject_pkg_dir = subproject.get_python_package_dir()
         subproject_pkg_init_file = subproject_pkg_dir.joinpath("__init__.py")