Configure property testing workflow

Author: SaridakisStamatisChristos

.github/workflows/ci.yml

@@ -21,13 +21,15 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-pip-
       - run: python -m pip install -U pip
-      - run: pip install -e ".[dev]"
-      - run: pytest -q --maxfail=1 --disable-warnings --cov=sudoku_dlx --cov-report=xml
+      - run: python -m pip install -e ".[dev]"
+      - name: Run tests (unit & integration only)
+        env:
+          HYPOTHESIS_PROFILE: ci
+        run: pytest -q --maxfail=1 --disable-warnings --cov=sudoku_dlx --cov-report=xml -m "not prop"
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v4
         with:
           token: ${{ secrets.CODECOV_TOKEN }}  # Not required for public repos
           files: ./coverage.xml
           flags: unittests
           fail_ci_if_error: false
-

.github/workflows/nightly_prop.yml

@@ -0,0 +1,21 @@
+name: nightly-prop
+
+on:
+  schedule:
+    - cron: "17 2 * * *"
+  workflow_dispatch: {}
+
+jobs:
+  property-tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - run: python -m pip install -U pip
+      - run: python -m pip install -e ".[dev]"
+      - name: Run property tests (nightly profile)
+        env:
+          HYPOTHESIS_PROFILE: nightly
+        run: pytest -q -m "prop"

pytest.ini

@@ -0,0 +1,7 @@
+[pytest]
+markers =
+    prop: property-based tests (slow; run nightly)
+addopts = -q
+filterwarnings =
+    ignore::DeprecationWarning
+    ignore::UserWarning

tests/conftest.py

@@ -7,6 +7,7 @@
 
 from _pytest.config import Config
 from _pytest.config.argparsing import Parser
+from hypothesis import HealthCheck, Phase, settings
 
 PROJECT_ROOT = Path(__file__).resolve().parents[1]
 SRC_PATH = PROJECT_ROOT / "src"
@@ -58,3 +59,28 @@ def pytest_configure(config: Config) -> None:
             "pytest-cov is not installed; coverage options are ignored.",
             stacklevel=2,
         )
+
+
+# Register lean Hypothesis profiles and select via env HYPOTHESIS_PROFILE
+# - "ci": very small example counts, no database, suppress flaky health checks.
+# - "nightly": larger runs with shrinking, no deadlines.
+settings.register_profile(
+    "ci",
+    max_examples=8,
+    phases=(Phase.generate, Phase.shrink),
+    deadline=None,
+    derandomize=True,
+    suppress_health_check=[
+        HealthCheck.too_slow,
+        HealthCheck.filter_too_much,
+        HealthCheck.data_too_large,
+    ],
+    database=None,
+)
+settings.register_profile(
+    "nightly",
+    max_examples=200,
+    phases=(Phase.generate, Phase.shrink),
+    deadline=None,
+)
+settings.load_profile(os.getenv("HYPOTHESIS_PROFILE", "default"))

tests/test_prop_canonical_simple.py

@@ -1,7 +1,11 @@
+import pytest
 from hypothesis import given, settings, strategies as st
 from sudoku_dlx import from_string, canonical_form
 
 # Keep canonical check cheap: compare original vs rot180 isomorph
+
+
+@pytest.mark.prop
 @settings(max_examples=10, deadline=None)
 @given(st.lists(st.sampled_from(list(".123456789")), min_size=81, max_size=81))
 def test_canonical_invariant_under_rot180(xs):

tests/test_prop_generate_minimal_unique.py

@@ -1,3 +1,5 @@
+import pytest
+
 from sudoku_dlx import generate, count_solutions
 
 
@@ -15,6 +17,7 @@ def _is_minimal_strict(g) -> bool:
     return True
 
 
+@pytest.mark.prop
 def test_generate_minimal_unique_fast_settings():
     # modest givens to keep runtime under control in CI
     for seed in [5, 9]:

tests/test_prop_parse.py

@@ -1,10 +1,12 @@
+import pytest
 from hypothesis import given, settings, strategies as st
 from sudoku_dlx import from_string, to_string
 
 # Allowed characters for parser (blanks + digits)
 chars = st.sampled_from(list(".0123456789"))
 
 
+@pytest.mark.prop
 @settings(max_examples=30, deadline=None)
 @given(st.lists(chars, min_size=81, max_size=81))
 def test_from_to_string_round_trip_preserves_clues(xs):
@@ -24,6 +26,7 @@ def test_from_to_string_round_trip_preserves_clues(xs):
 ws = st.text(alphabet=st.sampled_from(list(" \t\r\n")), min_size=0, max_size=20)
 
 
+@pytest.mark.prop
 @settings(max_examples=20, deadline=None)
 @given(st.lists(chars, min_size=81, max_size=81), ws, ws)
 def test_parser_ignores_whitespace(xs, pre, post):

tests/test_prop_solve_idempotent.py

@@ -1,3 +1,5 @@
+import pytest
+
 from sudoku_dlx import generate, solve
 
 
@@ -14,6 +16,7 @@ def _is_full_valid(grid):
     return all(s == expect for s in rows + cols + boxes)
 
 
+@pytest.mark.prop
 def test_solve_idempotent_and_valid_small_seedset():
     # keep seeds small for CI speed
     for seed in [1, 3, 7]: