build(typing): enable 'strict' mypy linting (#1527)

---------

Co-authored-by: Timothée Mazzucotelli <dev@pawamoy.fr>

copier/cli.py

@@ -52,15 +52,15 @@
 from os import PathLike
 from pathlib import Path
 from textwrap import dedent
-from typing import Callable
+from typing import Any, Callable, Iterable, Optional
 
 import yaml
 from plumbum import cli, colors
 
 from .errors import UnsafeTemplateError, UserMessageError
 from .main import Worker
 from .tools import copier_version
-from .types import AnyByStrDict, OptStr, StrSeq
+from .types import AnyByStrDict
 
 
 def _handle_exceptions(method: Callable[[], None]) -> int:
@@ -80,7 +80,7 @@ def _handle_exceptions(method: Callable[[], None]) -> int:
     return 0
 
 
-class CopierApp(cli.Application):
+class CopierApp(cli.Application):  # type: ignore[misc]
     """The Copier CLI application."""
 
     DESCRIPTION = "Create a new project from a template."
@@ -105,10 +105,10 @@ class CopierApp(cli.Application):
     CALL_MAIN_IF_NESTED_COMMAND = False
 
 
-class _Subcommand(cli.Application):
+class _Subcommand(cli.Application):  # type: ignore[misc]
     """Base class for Copier subcommands."""
 
-    def __init__(self, executable: PathLike) -> None:
+    def __init__(self, executable: "PathLike[str]") -> None:
         self.data: AnyByStrDict = {}
         super().__init__(executable)
 
@@ -158,14 +158,14 @@ def __init__(self, executable: PathLike) -> None:
         ),
     )
 
-    @cli.switch(
+    @cli.switch(  # type: ignore[misc]
         ["-d", "--data"],
         str,
         "VARIABLE=VALUE",
         list=True,
         help="Make VARIABLE available as VALUE when rendering the template",
     )
-    def data_switch(self, values: StrSeq) -> None:
+    def data_switch(self, values: Iterable[str]) -> None:
         """Update [data][] with provided values.
 
         Arguments:
@@ -176,7 +176,7 @@ def data_switch(self, values: StrSeq) -> None:
             key, value = arg.split("=", 1)
             self.data[key] = value
 
-    @cli.switch(
+    @cli.switch(  # type: ignore[misc]
         ["--data-file"],
         cli.ExistingFile,
         help="Load data from a YAML file",
@@ -195,7 +195,9 @@ def data_file_switch(self, path: cli.ExistingFile) -> None:
         }
         self.data.update(updates_without_cli_overrides)
 
-    def _worker(self, src_path: OptStr = None, dst_path: str = ".", **kwargs) -> Worker:
+    def _worker(
+        self, src_path: Optional[str] = None, dst_path: str = ".", **kwargs: Any  # noqa: FA100
+    ) -> Worker:
         """Run Copier's internal API using CLI switches.
 
         Arguments:

copier/main.py

@@ -13,7 +13,17 @@
 from pathlib import Path
 from shutil import rmtree
 from tempfile import TemporaryDirectory
-from typing import Callable, Iterable, Literal, Mapping, Sequence, get_args
+from types import TracebackType
+from typing import (
+    Any,
+    Callable,
+    Iterable,
+    Literal,
+    Mapping,
+    Sequence,
+    get_args,
+    overload,
+)
 from unicodedata import normalize
 
 from jinja2.loaders import FileSystemLoader
@@ -36,15 +46,7 @@
 from .subproject import Subproject
 from .template import Task, Template
 from .tools import OS, Style, normalize_git_path, printf, readlink
-from .types import (
-    MISSING,
-    AnyByStrDict,
-    JSONSerializable,
-    OptStr,
-    RelativePath,
-    StrOrPath,
-    StrSeq,
-)
+from .types import MISSING, AnyByStrDict, JSONSerializable, RelativePath, StrOrPath
 from .user_data import DEFAULT_DATA, AnswersMap, Question
 from .vcs import get_git
 
@@ -162,11 +164,11 @@ class Worker:
     src_path: str | None = None
     dst_path: Path = Path(".")
     answers_file: RelativePath | None = None
-    vcs_ref: OptStr = None
+    vcs_ref: str | None = None
     data: AnyByStrDict = field(default_factory=dict)
-    exclude: StrSeq = ()
+    exclude: Sequence[str] = ()
     use_prereleases: bool = False
-    skip_if_exists: StrSeq = ()
+    skip_if_exists: Sequence[str] = ()
     cleanup_on_error: bool = True
     defaults: bool = False
     user_defaults: AnyByStrDict = field(default_factory=dict)
@@ -179,13 +181,26 @@ class Worker:
     skip_answered: bool = False
 
     answers: AnswersMap = field(default_factory=AnswersMap, init=False)
-    _cleanup_hooks: list[Callable] = field(default_factory=list, init=False)
+    _cleanup_hooks: list[Callable[[], None]] = field(default_factory=list, init=False)
 
-    def __enter__(self):
+    def __enter__(self) -> Worker:
         """Allow using worker as a context manager."""
         return self
 
-    def __exit__(self, type, value, traceback):
+    @overload
+    def __exit__(self, type: None, value: None, traceback: None) -> None: ...
+
+    @overload
+    def __exit__(
+        self, type: type[BaseException], value: BaseException, traceback: TracebackType
+    ) -> None: ...
+
+    def __exit__(
+        self,
+        type: type[BaseException] | None,
+        value: BaseException | None,
+        traceback: TracebackType | None,
+    ) -> None:
         """Clean up garbage files after worker usage ends."""
         if value is not None:
             # exception was raised from code inside context manager:
@@ -196,7 +211,7 @@ def __exit__(self, type, value, traceback):
         # otherwise clean up and let any exception bubble up
         self._cleanup()
 
-    def _cleanup(self):
+    def _cleanup(self) -> None:
         """Execute all stored cleanup methods."""
         for method in self._cleanup_hooks:
             method()
@@ -226,7 +241,7 @@ def _print_message(self, message: str) -> None:
         if message and not self.quiet:
             print(self._render_string(message), file=sys.stderr)
 
-    def _answers_to_remember(self) -> Mapping:
+    def _answers_to_remember(self) -> Mapping[str, Any]:
         """Get only answers that will be remembered in the copier answers file."""
         # All internal values must appear first
         answers: AnyByStrDict = {}
@@ -273,7 +288,7 @@ def _execute_tasks(self, tasks: Sequence[Task]) -> None:
             with local.cwd(self.subproject.local_abspath), local.env(**task.extra_env):
                 subprocess.run(task_cmd, shell=use_shell, check=True, env=local.env)
 
-    def _render_context(self) -> Mapping:
+    def _render_context(self) -> Mapping[str, Any]:
         """Produce render context for Jinja."""
         # Backwards compatibility
         # FIXME Remove it?
@@ -305,7 +320,7 @@ def _path_matcher(self, patterns: Iterable[str]) -> Callable[[Path], bool]:
         spec = PathSpec.from_lines("gitwildmatch", normalized_patterns)
         return spec.match_file
 
-    def _solve_render_conflict(self, dst_relpath: Path):
+    def _solve_render_conflict(self, dst_relpath: Path) -> bool:
         """Properly solve render conflicts.
 
         It can ask the user if running in interactive mode.
@@ -468,7 +483,7 @@ def answers_relpath(self) -> Path:
         return Path(template.render(**self.answers.combined))
 
     @cached_property
-    def all_exclusions(self) -> StrSeq:
+    def all_exclusions(self) -> Sequence[str]:
         """Combine default, template and user-chosen exclusions."""
         return self.template.exclude + tuple(self.exclude)
 
@@ -766,7 +781,7 @@ def run_recopy(self) -> None:
                 f"from `{self.subproject.answers_relpath}`."
             )
         with replace(self, src_path=self.subproject.template.url) as new_worker:
-            return new_worker.run_copy()
+            new_worker.run_copy()
 
     def run_update(self) -> None:
         """Update a subproject that was already generated.
@@ -818,7 +833,7 @@ def run_update(self) -> None:
         self._apply_update()
         self._print_message(self.template.message_after_update)
 
-    def _apply_update(self):  # noqa: C901
+    def _apply_update(self) -> None:  # noqa: C901
         git = get_git()
         subproject_top = Path(
             git(
@@ -840,8 +855,8 @@ def _apply_update(self):  # noqa: C901
                 data=self.subproject.last_answers,
                 defaults=True,
                 quiet=True,
-                src_path=self.subproject.template.url,
-                vcs_ref=self.subproject.template.commit,
+                src_path=self.subproject.template.url,  # type: ignore[union-attr]
+                vcs_ref=self.subproject.template.commit,  # type: ignore[union-attr]
             ) as old_worker:
                 old_worker.run_copy()
             # Extract diff between temporary destination and real destination
@@ -863,7 +878,7 @@ def _apply_update(self):  # noqa: C901
                     diff = diff_cmd("--inter-hunk-context=0")
             # Run pre-migration tasks
             self._execute_tasks(
-                self.template.migration_tasks("before", self.subproject.template)
+                self.template.migration_tasks("before", self.subproject.template)  # type: ignore[arg-type]
             )
             # Clear last answers cache to load possible answers migration, if skip_answered flag is not set
             if self.skip_answered is False:
@@ -885,10 +900,10 @@ def _apply_update(self):  # noqa: C901
             with replace(
                 self,
                 dst_path=new_copy / subproject_subdir,
-                data=self.answers.combined,
+                data=self.answers.combined,  # type: ignore[arg-type]
                 defaults=True,
                 quiet=True,
-                src_path=self.subproject.template.url,
+                src_path=self.subproject.template.url,  # type: ignore[union-attr]
             ) as new_worker:
                 new_worker.run_copy()
             compared = dircmp(old_copy, new_copy)
@@ -968,10 +983,10 @@ def _apply_update(self):  # noqa: C901
 
         # Run post-migration tasks
         self._execute_tasks(
-            self.template.migration_tasks("after", self.subproject.template)
+            self.template.migration_tasks("after", self.subproject.template)  # type: ignore[arg-type]
         )
 
-    def _git_initialize_repo(self):
+    def _git_initialize_repo(self) -> None:
         """Initialize a git repository in the current directory."""
         git = get_git()
         git("init", retcode=None)
@@ -1004,7 +1019,7 @@ def run_copy(
     src_path: str,
     dst_path: StrOrPath = ".",
     data: AnyByStrDict | None = None,
-    **kwargs,
+    **kwargs: Any,
 ) -> Worker:
     """Copy a template to a destination, from zero.
 
@@ -1020,7 +1035,7 @@ def run_copy(
 
 
 def run_recopy(
-    dst_path: StrOrPath = ".", data: AnyByStrDict | None = None, **kwargs
+    dst_path: StrOrPath = ".", data: AnyByStrDict | None = None, **kwargs: Any
 ) -> Worker:
     """Update a subproject from its template, discarding subproject evolution.
 
@@ -1038,7 +1053,7 @@ def run_recopy(
 def run_update(
     dst_path: StrOrPath = ".",
     data: AnyByStrDict | None = None,
-    **kwargs,
+    **kwargs: Any,
 ) -> Worker:
     """Update a subproject, from its template.
 
@@ -1053,7 +1068,7 @@ def run_update(
     return worker
 
 
-def _remove_old_files(prefix: Path, cmp: dircmp, rm_common: bool = False) -> None:
+def _remove_old_files(prefix: Path, cmp: dircmp[str], rm_common: bool = False) -> None:
     """Remove files and directories only found in "old" template.
 
     This is an internal helper method used to process a comparison of 2

copier/subproject.py

@@ -33,7 +33,7 @@ class Subproject:
     local_abspath: AbsolutePath
     answers_relpath: Path = Path(".copier-answers.yml")
 
-    _cleanup_hooks: list[Callable] = field(default_factory=list, init=False)
+    _cleanup_hooks: list[Callable[[], None]] = field(default_factory=list, init=False)
 
     def is_dirty(self) -> bool:
         """Indicate if the local template root is dirty.
@@ -45,7 +45,7 @@ def is_dirty(self) -> bool:
                 return bool(get_git()("status", "--porcelain").strip())
         return False
 
-    def _cleanup(self):
+    def _cleanup(self) -> None:
         """Remove temporary files and folders created by the subproject."""
         for method in self._cleanup_hooks:
             method()
@@ -78,9 +78,11 @@ def template(self) -> Template | None:
             result = Template(url=last_url, ref=last_ref)
             self._cleanup_hooks.append(result._cleanup)
             return result
+        return None
 
     @cached_property
     def vcs(self) -> VCSTypes | None:
         """VCS type of the subproject."""
         if is_in_git_repo(self.local_abspath):
             return "git"
+        return None