ci: Add mypy action (#365)

* Add mypy to tests.yml
* Add explanation on how to run mypy in CONTRIBUTING.md

Author: ValerianRey

.github/workflows/tests.yml

@@ -72,3 +72,21 @@ jobs:
       - name: Build Documentation
         working-directory: docs
         run: uv run make dirhtml
+
+  mypy:
+    name: Run mypy
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    - name: Set up uv
+      uses: astral-sh/setup-uv@v5
+      with:
+        python-version: '3.13'
+
+    - name: Install dependencies (default with full options & check)
+      run: uv pip install '.[full]' --group check
+
+    - name: Run mypy
+      run: uv run mypy src/torchjd

CONTRIBUTING.md

@@ -72,6 +72,13 @@ mandatory, we only provide installation steps with this tool. You can install it
      uv run make clean
      ```
 
+## Running `mypy`
+
+From the root of the repo, run:
+```bash
+uv run mypy src/torchjd
+```
+
 ## Development guidelines
 
 The following guidelines should help preserve a good code quality in TorchJD. Contributions that do

pyproject.toml

@@ -42,7 +42,8 @@ Changelog = "https://github.com/TorchJD/torchjd/blob/main/CHANGELOG.md"
 
 [dependency-groups]
 check = [
-    "pre-commit>=2.9.2"  # isort doesn't work before 2.9.2
+    "mypy>=1.16.0",
+    "pre-commit>=2.9.2",  # isort doesn't work before 2.9.2
 ]
 
 doc = [