. e add mypy to the build

Author: JayBazuzi

.mise.toml

@@ -2,8 +2,21 @@
 uv = "latest"
 python = "latest"
 
+[env.'_'.python.venv]
+path = ".venv"
+create = true
+uv_create_args = ["--seed", "--quiet"]
+
 [tasks.build_and_test]
-depends = ["validate"]
+depends = ["validate", "mypy"]
+
+[tasks.validate]
+run = "python _validate.py"
+depends = ["pip-install"]
+
+[tasks.mypy]
+run = "mypy ."
+depends = ["pip-install"]
 
-[tasks]
-validate = "python _validate.py"
+[tasks.pip-install]
+run = "pip install --requirement requirements.txt --quiet --disable-pip-version-check"

.mypy.ini

@@ -0,0 +1,9 @@
+# Global options:
+
+[mypy]
+strict = True
+
+exclude = (?x)(         
+    ^\.venv/ |
+    ^\.ignore/
+  )

AGENT.md

@@ -0,0 +1 @@
+To run the build, use the `./build_and_test` script.

CLAUDE.md

@@ -0,0 +1 @@
+Read and follow AGENT.md.

_validate.py

@@ -8,7 +8,7 @@
 VALID_OS = {"Mac", "Windows", "Linux"}
 SCREAMING_SNAKE_RE = re.compile(r"^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$")
 
-def main():
+def main() -> None:
     errors = []
 
     with Path("diff_reporters.csv").open(newline="") as f:

requirements.txt

@@ -0,0 +1 @@
+mypy