python/pyspark/testing/tests/test_changed_files.py

#
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# contributor license agreements.  See the NOTICE file distributed with
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# The ASF licenses this file to You under the Apache License, Version 2.0
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# the License.  You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
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#
import os
import tempfile
import unittest

from pyspark.testing.utils import (
    PySparkBaseTestCase,
    grimp_requirement_message,
    have_grimp,
)

# A test module and modules it does / does not import (transitively). These relationships are
# stable parts of the pyspark import graph.
_TEST_MODULE = "pyspark.sql.tests.test_functions"
_RELEVANT_FILE = "python/pyspark/sql/functions/builtin.py"  # imported by _TEST_MODULE
_IRRELEVANT_FILE = "python/pyspark/ml/classification.py"  # not imported by _TEST_MODULE


@unittest.skipIf(not have_grimp, grimp_requirement_message)
class ChangedFilesSelectionTests(unittest.TestCase):
    """Tests for the "smart" test selection driven by PYSPARK_CHANGED_FILES.

    ``PySparkBaseTestCase.skip_if_changed_files_irrelevant`` skips a test class when none of the
    changed files' modules are reachable from the test's own module in the pyspark import graph.
    These exercise that logic directly against real pyspark modules with known relationships.
    """

    def setUp(self):
        # The relevance check is memoized with functools.cache; clear it so each case starts fresh.
        PySparkBaseTestCase._is_module_relevant_to_changed_files.cache_clear()

    def _is_relevant(self, module, files):
        with tempfile.NamedTemporaryFile("w") as f:
            f.write("\n".join(files))
            f.flush()
            return PySparkBaseTestCase._is_module_relevant_to_changed_files(module, f.name)

    def test_relevance(self):
        own_file = "python/" + _TEST_MODULE.replace(".", os.path.sep) + ".py"
        cases = [
            ("imported module is relevant", [_RELEVANT_FILE], True),
            ("unimported module is irrelevant", [_IRRELEVANT_FILE], False),
            ("relevant among irrelevant is relevant", [_IRRELEVANT_FILE, _RELEVANT_FILE], True),
            ("the test's own file is relevant via the self-module short circuit", [own_file], True),
            (
                "non-pyspark files are conservatively relevant",
                ["sql/core/src/main/scala/Foo.scala"],
                True,
            ),
            (
                "package __init__ with no graph node is conservatively relevant",
                ["python/pyspark/sql/__init__.py"],
                True,
            ),
        ]
        for desc, files, expected in cases:
            with self.subTest(desc):
                self.assertEqual(self._is_relevant(_TEST_MODULE, files), expected)

    def test_skip_if_changed_files_irrelevant(self):
        class _Dummy(PySparkBaseTestCase):
            pass

        _Dummy.__module__ = _TEST_MODULE

        # Irrelevant changes raise SkipTest.
        with tempfile.NamedTemporaryFile("w") as f:
            f.write(_IRRELEVANT_FILE)
            f.flush()
            with self.assertRaises(unittest.SkipTest):
                _Dummy.skip_if_changed_files_irrelevant(f.name)

        # Relevant changes do not.
        with tempfile.NamedTemporaryFile("w") as f:
            f.write(_RELEVANT_FILE)
            f.flush()
            _Dummy.skip_if_changed_files_irrelevant(f.name)


if __name__ == "__main__":
    from pyspark.testing import main

    main()