Add type annotations for spin utils (#188)

With this in place, we can progressively add more type annotations.

Closes #177

.pre-commit-config.yaml

@@ -40,3 +40,8 @@ repos:
     hooks:
       - id: ruff
         args: [--fix, --exit-non-zero-on-fix]
+
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: e5ea6670624c24f8321f6328ef3176dbba76db46 # frozen: v1.10.0
+    hooks:
+      - id: mypy

example_pkg/doc/conf.py

@@ -13,7 +13,7 @@
 # -- General configuration ---------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#general-configuration
 
-extensions = []
+extensions: list[str] = []
 
 templates_path = ["_templates"]
 exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]

spin/cmds/meson.py

@@ -215,9 +215,9 @@ def _check_coverage_tool_installation(coverage_type: GcovReportFormat):
 
     # Verify the tools are installed prior to the build
     p = _run(["ninja", "-C", build_dir, "-t", "targets", "all"], output=False)
-    if f"coverage-{coverage_type.value}" not in p.stdout.decode("ascii"):
+    if f"coverage-{coverage_type}" not in p.stdout.decode("ascii"):
         raise click.ClickException(
-            f"coverage-{coverage_type.value} is not supported... "
+            f"coverage-{coverage_type} is not supported... "
             f"Ensure the following are installed: {', '.join(requirements[coverage_type])} "
             "and rerun `spin test --gcov`"
         )
@@ -363,7 +363,7 @@ def _get_configured_command(command_name):
 )
 @click.option(
     "--gcov-format",
-    type=click.Choice(GcovReportFormat),
+    type=click.Choice([e.name for e in GcovReportFormat]),
     default="html",
     help=f"Format of the gcov report. Can be one of {', '.join(e.value for e in GcovReportFormat)}.",
 )
@@ -512,7 +512,7 @@ def test(
 
         # Generate report
         click.secho(
-            f"Generating {gcov_format.value} coverage report...",
+            f"Generating {gcov_format} coverage report...",
             bold=True,
             fg="bright_yellow",
         )
@@ -521,7 +521,7 @@ def test(
                 "ninja",
                 "-C",
                 build_dir,
-                f"coverage-{gcov_format.value.lower()}",
+                f"coverage-{gcov_format.lower()}",
             ],
             output=False,
         )

spin/cmds/util.py

@@ -2,13 +2,21 @@
 import shlex
 import subprocess
 import sys
+from typing import Optional
 
 import click
 
 
 def run(
-    cmd, cwd=None, replace=False, sys_exit=True, output=True, echo=True, *args, **kwargs
-):
+    cmd: list[str],
+    cwd: Optional[str] = None,  # in 3.10 and up: str | None
+    replace: bool = False,
+    sys_exit: bool = True,
+    output: bool = True,
+    echo: bool = True,
+    *args,
+    **kwargs,
+) -> subprocess.CompletedProcess:
     """Run a shell command.
 
     Parameters