From 398d72cbe73ce88af12b21fcff92c205921126f9 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend@python.org>
Date: Thu, 11 Jul 2024 12:48:22 +0200
Subject: [PATCH] gh-358: Add mypy CI and config

Estalish a minimal mypy config that ensures annotations are compatible
with Python 3.8 (the oldest supported Python version).

Add a forgiving CI job that does not affect the status of the GitHub
workflow run.
---
 .github/workflows/pythonpackage.yml | 15 +++++++++++++++
 pyproject.toml                      |  8 ++++++++
 requirements-dev.txt                |  1 +
 3 files changed, 24 insertions(+)
 create mode 100644 requirements-dev.txt

diff --git a/.github/workflows/pythonpackage.yml b/.github/workflows/pythonpackage.yml
index 427ad9c7..76cc9e8d 100644
--- a/.github/workflows/pythonpackage.yml
+++ b/.github/workflows/pythonpackage.yml
@@ -53,3 +53,18 @@ jobs:
       run: python3 -m pip install -r doc/requirements.txt -e .
     - name: Build docs
       run: make -C doc html
+
+  mypy:
+    continue-on-error: true
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-python@v5
+      with:
+        python-version: "3.8"
+        cache: pip
+        cache-dependency-path: |
+          'pyproject.toml'
+          'requirements-dev.txt'
+    - run: pip install -r requirements-dev.txt
+    - run: mypy --config-file pyproject.toml .
diff --git a/pyproject.toml b/pyproject.toml
index a87ba589..e9c85993 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -48,3 +48,11 @@ testpaths = [
 filterwarnings = [
     "ignore::DeprecationWarning",
 ]
+
+[tool.mypy]
+python_version = "3.8"
+exclude = [
+    "^examples*",
+    "^test*",
+    "^setup.py*",
+]
diff --git a/requirements-dev.txt b/requirements-dev.txt
new file mode 100644
index 00000000..ede5a914
--- /dev/null
+++ b/requirements-dev.txt
@@ -0,0 +1 @@
+mypy~=1.10