Add integration test CI and skip integration tests by default

- Mark PostgreSQL integration tests with @pytest.mark.integration
- Configure pytest to skip integration tests by default with addopts
- Create .github/workflows/integration.yml for PostgreSQL integration CI
- Update docker-compose to use pytest -m integration
- Fix ruff errors (unused imports and variables)
- Update tests/db/README.md with marker-based test running instructions

Normal pytest runs now skip integration tests (566 tests pass, 10 deselected).
Integration tests run separately in CI with postgres service.

Author: nicosuave

.github/workflows/integration.yml

@@ -0,0 +1,46 @@
+name: Integration Tests
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  postgres-integration:
+    runs-on: ubuntu-latest
+
+    services:
+      postgres:
+        image: postgres:16-alpine
+        env:
+          POSTGRES_USER: test
+          POSTGRES_PASSWORD: test
+          POSTGRES_DB: sidemantic_test
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v5
+        with:
+          enable-cache: true
+
+      - name: Set up Python
+        run: uv python install 3.12
+
+      - name: Install dependencies
+        run: uv sync --extra postgres --extra dev
+
+      - name: Run PostgreSQL integration tests
+        env:
+          POSTGRES_TEST: "1"
+          POSTGRES_URL: "postgres://test:test@localhost:5432/sidemantic_test"
+        run: uv run pytest -m integration -v

docker-compose.yml

@@ -25,7 +25,7 @@ services:
     environment:
       POSTGRES_TEST: "1"
       POSTGRES_URL: "postgres://test:test@postgres:5432/sidemantic_test"
-    command: pytest tests/db/test_postgres_integration.py -v
+    command: pytest -m integration -v
 
 volumes:
   postgres_data:

pyproject.toml

@@ -86,6 +86,10 @@ ignore = ["E501", "N807"]  # N807: dunder methods like __init__ are supposed to
 [tool.pytest.ini_options]
 testpaths = ["tests"]
 pythonpath = ["."]
+markers = [
+    "integration: marks tests as integration tests requiring external services (deselect with '-m \"not integration\"')",
+]
+addopts = "-m 'not integration'"  # Skip integration tests by default
 
 [tool.uv]
 prerelease = "if-necessary"

tests/db/README.md

@@ -10,16 +10,16 @@ pytest tests/db/test_semantic_layer_adapters.py -v
 
 ### PostgreSQL Integration Tests
 
-PostgreSQL tests require a running Postgres instance and the `postgres` extra dependencies.
+PostgreSQL tests are marked with `@pytest.mark.integration` and skipped by default. They require a running Postgres instance and the `postgres` extra dependencies.
 
 **Using Docker Compose (recommended):**
 ```bash
-# Start Postgres and run tests
+# Start Postgres and run integration tests
 docker compose up test --build --abort-on-container-exit
 
 # Or run tests locally against dockerized Postgres
 docker compose up -d postgres
-POSTGRES_TEST=1 uv run --extra postgres pytest tests/db/test_postgres_integration.py -v
+POSTGRES_TEST=1 uv run --extra postgres pytest -m integration -v
 ```
 
 **Manual setup:**
@@ -31,10 +31,12 @@ uv sync --extra postgres
 export POSTGRES_TEST=1
 export POSTGRES_URL="postgres://test:test@localhost:5432/sidemantic_test"
 
-# Run tests
-uv run pytest tests/db/test_postgres_integration.py -v
+# Run integration tests only
+uv run pytest -m integration -v
 ```
 
+**Note:** Normal `pytest` runs will skip integration tests automatically. Use `-m integration` to run them explicitly.
+
 ## Test Coverage
 
 - **test_duckdb_adapter.py**: Tests for DuckDB adapter implementation

tests/db/test_postgres_adapter.py

@@ -18,10 +18,6 @@ def test_postgres_adapter_missing_dependency():
 
 def test_postgres_adapter_from_url_parsing():
     """Test URL parsing (without actually connecting)."""
-    # Test that URL parsing works correctly
-    # We can't test actual connection without a postgres instance
-    url = "postgres://user:pass@localhost:5432/testdb"
-
     # Just verify the from_url method exists and accepts the URL format
     # It will fail on connection but that's ok for this test
     assert hasattr(PostgreSQLAdapter, "from_url")

tests/db/test_postgres_integration.py

@@ -1,6 +1,6 @@
 """Integration tests for PostgreSQL adapter against real database.
 
-Run with: docker compose up -d && pytest tests/db/test_postgres_integration.py -v
+Run with: docker compose up -d && pytest -m integration tests/db/test_postgres_integration.py -v
 """
 
 import os
@@ -9,11 +9,14 @@
 
 from sidemantic import Dimension, Metric, Model, SemanticLayer
 
-# Skip all tests if POSTGRES_TEST environment variable not set
-pytestmark = pytest.mark.skipif(
-    os.getenv("POSTGRES_TEST") != "1",
-    reason="Set POSTGRES_TEST=1 and run docker compose up -d to run Postgres integration tests",
-)
+# Mark all tests in this module as integration tests
+pytestmark = [
+    pytest.mark.integration,
+    pytest.mark.skipif(
+        os.getenv("POSTGRES_TEST") != "1",
+        reason="Set POSTGRES_TEST=1 and run docker compose up -d to run Postgres integration tests",
+    ),
+]
 
 # Use environment variable for URL (different in docker vs local)
 POSTGRES_URL = os.getenv("POSTGRES_URL", "postgres://test:test@localhost:5433/sidemantic_test")

tests/db/test_semantic_layer_adapters.py

@@ -2,7 +2,7 @@
 
 import pytest
 
-from sidemantic import Dimension, Metric, Model, SemanticLayer
+from sidemantic import Metric, Model, SemanticLayer
 from sidemantic.db.duckdb import DuckDBAdapter