Add coverage support

Author: rsyring

.github/actions/nox-run/action.yaml

@@ -21,3 +21,10 @@ runs:
       env:
         UV_LINK_MODE: copy
       shell: bash
+
+    - name: upload coverage artifact
+      if: contains(inputs.nox-session, 'pytest')
+      uses: actions/upload-artifact@v4
+      with:
+        name: coverage-${{ inputs.nox-session }}
+        path: ci/test-reports/${{ inputs.nox-session }}.pytests.xml

.github/workflows/nox.yaml

@@ -12,6 +12,12 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
+
+permissions:
+  contents: read     # for actions/checkout
+  id-token: write    # For codecov OIDC
+
+
 jobs:
   generate-matrix:
     runs-on: ubuntu-24.04
@@ -111,3 +117,26 @@ jobs:
       - uses: ./.github/actions/nox-run
         with:
           nox-session: ${{ matrix.session }}
+
+
+  codecov:
+    needs:  [nox-other, nox-pg, nox-mssq]
+    runs-on: ubuntu-latest
+
+    steps:
+      # Codecov action says we have to have done a checkout
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - uses: actions/download-artifact@v5
+        with:
+          path: ci/github-coverage
+          merge-multiple: true
+
+      - name: Coverage files
+        run: ls -R ci/
+
+      - uses: codecov/codecov-action@v5
+        with:
+          use_oidc: true
+          directory: ci/github-coverage

tasks/gh-nox-sessions

@@ -1,5 +1,5 @@
 #!/usr/bin/env python
-# mise description='Nox session list for GH CI'
+# mise description='Nox session groups for GH CI'
 import json
 from os import environ