Enable codecov coverage checks

.github/workflows/code-coverage.yml

@@ -0,0 +1,54 @@
+# Copyright 2024 The Sigstore Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Code Coverage
+
+on:
+  pull_request:
+    branches: [main]
+    types: [opened, synchronize]
+  push:
+    branches: [main]
+
+permissions: {}
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  coverage:
+    name: Upload code coverage
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      with:
+        persist-credentials: false
+    - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      with:
+        python-version: '3.12'
+    - name: Set up Hatch
+      uses: pypa/hatch@257e27e51a6a5616ed08a39a408a21c35c9931bc # install
+    - name: Run tests with coverage
+      run: hatch test -c -py 3.12
+    - name: Generate coverage XML report
+      run: hatch run hatch-test.py3.12:coverage xml
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@57e3a136b779b570ffcdbf80b3bdc90e7fab3de2 # v6
+      with:
+        files: coverage.xml
+        token: ${{ secrets.CODECOV_TOKEN }}
+        fail_ci_if_error: true

.gitignore

@@ -1,4 +1,6 @@
 .coverage
+coverage.xml
+htmlcov/
 .pytest_cache/
 .pytype/
 .ruff_cache/

codecov.yml

@@ -0,0 +1,10 @@
+coverage:
+  status:
+    patch:
+      default:
+        target: 70%
+        threshold: 5%
+    project:
+      default:
+        target: auto
+        informational: true