ci: Add coverage

This adds the coverage utility, to at least give an overview of how
much our testing covers

.github/workflows/coverage.yaml

@@ -0,0 +1,26 @@
+name: Check Coverage
+
+on:
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+          cache: pip
+      - name: Install Cally test dependencies
+        run: pip install .[test]
+      - name: Run Coverage
+        run: coverage run -m pytest
+      - name: Get Cover
+        uses: orgoro/[email protected]
+        with:
+            coverageFile: path/to/coverage.xml
+            token: ${{ secrets.GITHUB_TOKEN }}

pyproject.toml

@@ -20,6 +20,7 @@ license = {file = "LICENSE.md"}
 [project.optional-dependencies]
 development = [
   "black",
+  "coverage",
   "isort",
   "mypy",
   "pytest",
@@ -31,6 +32,7 @@ development = [
 ]
 test = [
   "black",
+  "coverage",
   "mypy",
   "pytest",
   "pytest-black",