test: add schema preprocessing coverage and CI

.github/workflows/tests.yml

@@ -0,0 +1,42 @@
+# Copyright 2026 UCP 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: Tests
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+jobs:
+  schema-preprocessing:
+    name: Schema preprocessing (Python ${{ matrix.python-version }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.10", "3.11", "3.12"]
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v5
+      - name: Set up Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Run preprocessing tests
+        run: python -m unittest discover -s tests -p "test_*.py"

README.md

@@ -140,6 +140,14 @@ If no version is specified, the `main` branch of the
 
 The generated code is automatically formatted using `ruff`.
 
+### Running Tests
+
+Run the schema preprocessing test suite with:
+
+```bash
+python -m unittest discover -s tests -p "test_*.py"
+```
+
 ## Contributing
 
 We welcome community contributions. See our