From 0f763969b3aa492447d321eb4a04775039112132 Mon Sep 17 00:00:00 2001
From: Deepak Cherian <deepak@cherian.net>
Date: Mon, 1 Apr 2024 17:52:38 -0600
Subject: [PATCH] Add hypothesis workflow

---
 .github/workflows/ci-additional.yaml  | 75 ++++++++++++++++++++++++++-
 properties/conftest.py                | 21 ++++++++
 properties/test_index_manipulation.py | 17 +++---
 pyproject.toml                        |  1 +
 4 files changed, 106 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/ci-additional.yaml b/.github/workflows/ci-additional.yaml
index 9aa3b17746f..4b90900568a 100644
--- a/.github/workflows/ci-additional.yaml
+++ b/.github/workflows/ci-additional.yaml
@@ -35,14 +35,13 @@ jobs:
     runs-on: "ubuntu-latest"
     needs: detect-ci-trigger
     if: needs.detect-ci-trigger.outputs.triggered == 'false'
+
     defaults:
       run:
         shell: bash -l {0}
-
     env:
       CONDA_ENV_FILE: ci/requirements/environment.yml
       PYTHON_VERSION: "3.11"
-
     steps:
       - uses: actions/checkout@v4
         with:
@@ -82,6 +81,78 @@ jobs:
           # [MHS, 01/25/2024] Skip datatree_ documentation remove after #8572
           python -m pytest --doctest-modules xarray --ignore xarray/tests --ignore xarray/datatree_ -Werror
 
+  hypothesis:
+    name: Doctests
+    runs-on: "ubuntu-latest"
+    needs: detect-ci-trigger
+    if: |
+        always()
+        && (
+            (github.event_name == 'schedule' || github.event_name == 'workflow_dispatch')
+            || needs.detect-ci-trigger.outputs.triggered == 'true'
+            || contains( github.event.pull_request.labels.*.name, 'run-slow-hypothesis')
+        )
+    defaults:
+      run:
+        shell: bash -l {0}
+
+    env:
+      CONDA_ENV_FILE: ci/requirements/environment.yml
+      PYTHON_VERSION: "3.12"
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0 # Fetch all history for all branches and tags.
+
+      - name: set environment variables
+        run: |
+          echo "TODAY=$(date  +'%Y-%m-%d')" >> $GITHUB_ENV
+
+      - name: Setup micromamba
+        uses: mamba-org/setup-micromamba@v1
+        with:
+          environment-file: ${{env.CONDA_ENV_FILE}}
+          environment-name: xarray-tests
+          create-args: >-
+            python=${{env.PYTHON_VERSION}}
+            conda
+          cache-environment: true
+          cache-environment-key: "${{runner.os}}-${{runner.arch}}-py${{env.PYTHON_VERSION}}-${{env.TODAY}}-${{hashFiles(env.CONDA_ENV_FILE)}}"
+
+      - name: Install xarray
+        run: |
+          python -m pip install --no-deps -e .
+      - name: Version info
+        run: |
+          conda info -a
+          conda list
+          python xarray/util/print_versions.py
+      - name: Restore cached hypothesis directory
+        uses: actions/cache@v4
+        with:
+          path: .hypothesis/
+          key: cache-hypothesis
+          enableCrossOsArchive: true
+          save-always: true
+      - name: Run slow Hypothesis tests
+        if: success()
+        id: status
+        run: |
+           python -m pytest --hypothesis-show-statistics --run-slow-hypothesis properties/*.py \
+             --report-log output-${{ matrix.python-version }}-log.jsonl
+      - name: Generate and publish the report
+        if: |
+          failure()
+          && steps.status.outcome == 'failure'
+          && github.event_name == 'schedule'
+          && github.repository_owner == 'pydata'
+        uses: xarray-contrib/issue-from-pytest-log@v1
+        with:
+          log-path: output-${{ matrix.python-version }}-log.jsonl
+          issue-title: "Nightly Hypothesis tests failed"
+          issue-label: "topic-hypothesis"
+
   mypy:
     name: Mypy
     runs-on: "ubuntu-latest"
diff --git a/properties/conftest.py b/properties/conftest.py
index 0a66d92ebc6..30e638161a1 100644
--- a/properties/conftest.py
+++ b/properties/conftest.py
@@ -1,3 +1,24 @@
+import pytest
+
+
+def pytest_addoption(parser):
+    parser.addoption(
+        "--run-slow-hypothesis",
+        action="store_true",
+        default=False,
+        help="run slow hypothesis tests",
+    )
+
+
+def pytest_collection_modifyitems(config, items):
+    if config.getoption("--run-slow-hypothesis"):
+        return
+    skip_slow_hyp = pytest.mark.skip(reason="need --run-slow-hypothesis option to run")
+    for item in items:
+        if "slow_hypothesis" in item.keywords:
+            item.add_marker(skip_slow_hyp)
+
+
 try:
     from hypothesis import settings
 except ImportError:
diff --git a/properties/test_index_manipulation.py b/properties/test_index_manipulation.py
index 5a9fd54c041..2e20c2b490f 100644
--- a/properties/test_index_manipulation.py
+++ b/properties/test_index_manipulation.py
@@ -7,6 +7,7 @@
 from xarray.testing import _assert_internal_invariants
 
 pytest.importorskip("hypothesis")
+pytestmark = pytest.mark.slow_hypothesis
 
 import hypothesis.strategies as st
 from hypothesis import note, settings
@@ -52,12 +53,7 @@ def __init__(self):
         self.multi_indexed_dims = []
 
     # TODO: stacking with a timedelta64 index and unstacking converts it to object
-    @rule(
-        var=xrst.index_variables(
-            dims=DIM_NAME,
-            dtype=xrst.pandas_index_dtypes().filter(lambda x: x.kind != "m"),
-        )
-    )
+    @rule(var=xrst.index_variables(dims=DIM_NAME, dtype=xrst.pandas_index_dtypes()))
     def add_dim_coord(self, var):
         (name,) = var.dims
         note(f"adding dimension coordinate {name}")
@@ -253,3 +249,12 @@ def test_unstack_object():
     ds = xr.Dataset()
     ds["0"] = np.array(["", "\x000"], dtype=object)
     ds.stack({"1": ["0"]}).unstack()
+
+
+@pytest.mark.skip(reason="failure detected by hypothesis")
+def test_unstack_timedelta_index():
+    import xarray as xr
+
+    ds = xr.Dataset()
+    ds["0"] = np.array([0, 1, 2, 3], dtype="timedelta64[ns]")
+    ds.stack({"1": ["0"]}).unstack()
diff --git a/pyproject.toml b/pyproject.toml
index d2a5c6b8748..532dc40e859 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -295,6 +295,7 @@ markers = [
   "flaky: flaky tests",
   "network: tests requiring a network connection",
   "slow: slow tests",
+  "slow_hypothesis: slow hypothesis tests",
 ]
 minversion = "7"
 python_files = "test_*.py"