chore(linters): Introduce ruff and fix issues

.pre-commit-config.yaml

@@ -98,6 +98,15 @@ repos:
   - id: shellcheck
 
 # Python
+- repo: https://github.com/astral-sh/ruff-pre-commit
+  rev: v0.8.4
+  hooks:
+  - id: ruff
+    args:
+    - --fix
+  - id: ruff-format
+    exclude: /terraform_docs_replace(_test)?\.py$
+
 - repo: https://github.com/pre-commit/mirrors-mypy.git
   rev: v1.15.0
   hooks:

ruff.toml

@@ -0,0 +1,39 @@
+# Assume Python 3.9
+target-version = "py39"
+
+line-length = 79 # To decrease PR diff size
+
+namespace-packages = ["src/pre_commit_terraform/", "tests/pytest/"]
+
+[format]
+quote-style = "single"
+
+[lint.flake8-quotes]
+inline-quotes = "single"
+
+[lint.pydocstyle]
+convention = "pep257"
+
+[lint]
+select = ["ALL"]
+preview = true
+ignore = [
+  "CPY001", # Missing copyright notice at top of file
+]
+
+[lint.isort]
+# force-single-line = true # To decrease PR diff size
+lines-after-imports = 2
+
+[lint.flake8-pytest-style]
+parametrize-values-type = "tuple"
+
+[lint.per-file-ignores]
+# Ignore in the `tests/` directory.
+"tests/**.py" = [
+  "S101", # Use of `assert` detected
+  "PLC2701", # We need import marked as internal files for testing
+]
+
+"src/pre_commit_terraform/terraform_docs_replace.py" = ["ALL"] # Deprecated hook
+"tests/pytest/terraform_docs_replace_test.py" = ["ALL"] # Tests for deprecated hook

src/pre_commit_terraform/_cli.py

@@ -21,35 +21,38 @@ def invoke_cli_app(cli_args: list[str]) -> ReturnCodeType:
 
     Returns:
         ReturnCodeType: The return code of the app.
+
+    Raises:
+        PreCommitTerraformExit: If the app is exiting with error.
     """
     root_cli_parser = initialize_argument_parser()
     parsed_cli_args = root_cli_parser.parse_args(cli_args)
     invoke_cli_app = cast_to(
-        # FIXME: attempt typing per https://stackoverflow.com/a/75666611/595220
+        # FIXME: attempt typing per https://stackoverflow.com/a/75666611/595220  # noqa: TD001, TD002, TD003, FIX001, E501
         'CLIAppEntryPointCallableType',
         parsed_cli_args.invoke_cli_app,
     )
 
     try:
         return invoke_cli_app(parsed_cli_args)
     except PreCommitTerraformExit as exit_err:
-        print(f'App exiting: {exit_err !s}', file=sys.stderr)
+        print(f'App exiting: {exit_err !s}', file=sys.stderr)  # noqa: T201 FIXME
         raise
     except PreCommitTerraformRuntimeError as unhandled_exc:
-        print(
+        print(  # noqa: T201 FIXME
             f'App execution took an unexpected turn: {unhandled_exc !s}. '
             'Exiting...',
             file=sys.stderr,
         )
         return ReturnCode.ERROR
     except PreCommitTerraformBaseError as unhandled_exc:
-        print(
+        print(  # noqa: T201 FIXME
             f'A surprising exception happened: {unhandled_exc !s}. Exiting...',
             file=sys.stderr,
         )
         return ReturnCode.ERROR
     except KeyboardInterrupt as ctrl_c_exc:
-        print(
+        print(  # noqa: T201 FIXME
             f'User-initiated interrupt: {ctrl_c_exc !s}. Exiting...',
             file=sys.stderr,
         )

src/pre_commit_terraform/_errors.py

@@ -12,5 +12,5 @@ class PreCommitTerraformRuntimeError(
     """An exception representing a runtime error condition."""
 
 
-class PreCommitTerraformExit(PreCommitTerraformBaseError, SystemExit):
+class PreCommitTerraformExit(PreCommitTerraformBaseError, SystemExit):  # noqa: N818 FIXME
     """An exception for terminating execution from deep app layers."""

tests/pytest/_cli_test.py

@@ -51,13 +51,13 @@ def test_known_interrupts(
     class CustomCmdStub:
         CLI_SUBCOMMAND_NAME = 'sentinel'
 
-        def populate_argument_parser(
+        def populate_argument_parser(  # noqa: PLR6301
             self,
-            subcommand_parser: ArgumentParser,
+            subcommand_parser: ArgumentParser,  # noqa: ARG002
         ) -> None:
             return None
 
-        def invoke_cli_app(self, parsed_cli_args: Namespace) -> ReturnCodeType:
+        def invoke_cli_app(self, parsed_cli_args: Namespace) -> ReturnCodeType:  # noqa: PLR6301, ARG002
             raise raised_error
 
     monkeypatch.setattr(
@@ -81,13 +81,16 @@ def test_app_exit(
     class CustomCmdStub:
         CLI_SUBCOMMAND_NAME = 'sentinel'
 
-        def populate_argument_parser(
+        def populate_argument_parser(  # noqa: PLR6301
             self,
-            subcommand_parser: ArgumentParser,
+            subcommand_parser: ArgumentParser,  # noqa: ARG002
         ) -> None:
             return None
 
-        def invoke_cli_app(self, parsed_cli_args: Namespace) -> ReturnCodeType:
+        def invoke_cli_app(
+            self,
+            parsed_cli_args: Namespace,  # noqa: ARG002
+        ) -> ReturnCodeType:
             raise PreCommitTerraformExit(self.CLI_SUBCOMMAND_NAME)
 
     monkeypatch.setattr(