Python TAP test conversion using pytest

.github/workflows/pg-ci.yml

@@ -88,9 +88,10 @@ env:
     -Dplperl=enabled
     -Dplpython=enabled
     -Dpltcl=enabled
+    -Dpytest=enabled
     -Dreadline=enabled
     -Dssl=openssl
-    -Dtap_tests=enabled
+    -Dtap_tests=disabled
     -Dzlib=enabled
     -Dzstd=enabled
 
@@ -521,6 +522,7 @@ jobs:
             --pkg-config-path /usr/lib/i386-linux-gnu/pkgconfig/ \
             -DPERL=perl5.40-i386-linux-gnu \
             -Dlibnuma=disabled \
+            -Dtap_tests=disabled \
             build
 
       - name: Build
@@ -607,6 +609,7 @@ jobs:
             -Duuid=e2fs \
             --buildtype=debug \
             -Dllvm=enabled \
+            -Dtap_tests=disabled \
             build
 
       - name: Build
@@ -617,6 +620,15 @@ jobs:
 
       - name: Test world
         shell: *su_postgres_shell
+        # The pytest suite loads libpq in-process via ctypes.  Here libpq is
+        # AddressSanitizer-instrumented, and ASan must come first in the link
+        # order; dlopening it into an otherwise uninstrumented python aborts
+        # with "ASan runtime does not come first".  Preload the ASan runtime
+        # for the test run to satisfy that (a no-op for the already-instrumented
+        # server/client binaries).  Scoped to this step so the build is
+        # unaffected; detect_leaks is already disabled via ASAN_OPTIONS.
+        env:
+          ADDITIONAL_SETUP: export LD_PRELOAD="$(gcc -print-file-name=libasan.so)"
         run: *meson_test_world_cmd
 
       - *linux_collect_cores_step
@@ -659,6 +671,8 @@ jobs:
         openssl
         p5.34-io-tty
         p5.34-ipc-run
+        py312-pexpect
+        py312-pytest
         python312
         tcl
         zstd
@@ -815,8 +829,9 @@ jobs:
         -Dldap=enabled
         -Dplperl=enabled
         -Dplpython=enabled
+        -Dpytest=enabled
         -Dssl=openssl
-        -Dtap_tests=enabled
+        -Dtap_tests=disabled
 
     defaults:
       run:
@@ -902,9 +917,11 @@ jobs:
       - name: Install dependencies
         shell: pwsh
         run: |
-          # meson is not preinstalled on windows-2022. Install via pip
+          # meson is not preinstalled on windows-2022. Install via pip.
+          # pytest enables the Python test suite (pexpect is omitted: it needs
+          # a pty, which Windows lacks, and the interactive tests importorskip).
           echo ::group::pip
-          python -m pip install --upgrade meson
+          python -m pip install --upgrade meson pytest
           if (!$?) { throw 'cmdfail' }
           echo ::endgroup::
 
@@ -1042,6 +1059,7 @@ jobs:
             ${MINGW_PACKAGE_PREFIX}-meson \
             ${MINGW_PACKAGE_PREFIX}-perl \
             ${MINGW_PACKAGE_PREFIX}-pkgconf \
+            ${MINGW_PACKAGE_PREFIX}-python-pytest \
             ${MINGW_PACKAGE_PREFIX}-readline \
             ${MINGW_PACKAGE_PREFIX}-zlib \
             ${MINGW_PACKAGE_PREFIX}-zstd

contrib/amcheck/meson.build

@@ -52,4 +52,14 @@ tests += {
       't/006_verify_gin.pl',
     ],
   },
+  'pytest': {
+    'tests': [
+      'pyt/test_001_verify_heapam.py',
+      'pyt/test_002_cic.py',
+      'pyt/test_003_cic_2pc.py',
+      'pyt/test_004_verify_nbtree_unique.py',
+      'pyt/test_005_pitr.py',
+      'pyt/test_006_verify_gin.py',
+    ],
+  },
 }

contrib/amcheck/pyt/test_001_verify_heapam.py

@@ -0,0 +1,219 @@
+# Copyright (c) 2021-2026, PostgreSQL Global Development Group
+
+"""Test amcheck's verify_heapam against deliberately corrupted heap pages."""
+
+import os
+import re
+import struct
+
+
+# Regexes matching the various line-pointer-corruption checks in
+# verify_heapam.c, hit by corrupt_first_page on both little-endian and
+# big-endian architectures.
+_HEAP_CORRUPTION_RES = [
+    re.compile(
+        r"line pointer redirection to item at offset \d+ "
+        r"precedes minimum offset \d+"
+    ),
+    re.compile(
+        r"line pointer redirection to item at offset \d+ "
+        r"exceeds maximum offset \d+"
+    ),
+    re.compile(r"line pointer to page offset \d+ is not maximally aligned"),
+    re.compile(
+        r"line pointer length \d+ is less than the minimum "
+        r"tuple header size \d+"
+    ),
+    re.compile(
+        r"line pointer to page offset \d+ with length \d+ "
+        r"ends beyond maximum page offset \d+"
+    ),
+]
+
+
+def relation_filepath(node, session, relname):
+    """Return the filesystem path for the named relation."""
+    pgdata = node.data_dir
+    rel = session.query_oneval(f"SELECT pg_relation_filepath('{relname}')")
+    assert rel is not None, f"path not found for relation {relname}"
+    return os.path.join(pgdata, rel)
+
+
+def fresh_test_table(session, relname):
+    """(Re)create and populate a test table of the given name."""
+    return session.do(
+        f"""
+        DROP TABLE IF EXISTS {relname} CASCADE;
+        CREATE TABLE {relname} (a integer, b text);
+        ALTER TABLE {relname} SET (autovacuum_enabled=false);
+        ALTER TABLE {relname} ALTER b SET STORAGE external;
+        INSERT INTO {relname} (a, b)
+            (SELECT gs, repeat('b',gs*10) FROM generate_series(1,1000) gs);
+        BEGIN;
+        SAVEPOINT s1;
+        SELECT 1 FROM {relname} WHERE a = 42 FOR UPDATE;
+        UPDATE {relname} SET b = b WHERE a = 42;
+        RELEASE s1;
+        SAVEPOINT s1;
+        SELECT 1 FROM {relname} WHERE a = 42 FOR UPDATE;
+        UPDATE {relname} SET b = b WHERE a = 42;
+        COMMIT;
+    """
+    )
+
+
+def fresh_test_sequence(session, seqname):
+    """Create a test sequence of the given name."""
+    return session.do(
+        f"""
+        DROP SEQUENCE IF EXISTS {seqname} CASCADE;
+        CREATE SEQUENCE {seqname}
+            INCREMENT BY 13
+            MINVALUE 17
+            START WITH 23;
+        SELECT nextval('{seqname}');
+        SELECT setval('{seqname}', currval('{seqname}') + nextval('{seqname}'));
+    """
+    )
+
+
+def advance_test_sequence(session, seqname):
+    """Call SQL functions to increment the sequence."""
+    return session.query_oneval(f"SELECT nextval('{seqname}')")
+
+
+def set_test_sequence(session, seqname):
+    """Call SQL functions to set the sequence."""
+    return session.query_oneval(f"SELECT setval('{seqname}', 102)")
+
+
+def reset_test_sequence(session, seqname):
+    """Call SQL functions to reset the sequence."""
+    return session.do(f"ALTER SEQUENCE {seqname} RESTART WITH 51")
+
+
+def corrupt_first_page(node, session, relname):
+    """Stop the node, corrupt the first page of the relation, restart it."""
+    relpath = relation_filepath(node, session, relname)
+
+    session.close()
+    node.stop()
+
+    with open(relpath, "r+b") as fh:
+        # Corrupt some line pointers.  The values are chosen to hit the
+        # various line-pointer-corruption checks in verify_heapam.c
+        # on both little-endian and big-endian architectures.
+        fh.seek(32)
+        fh.write(
+            struct.pack(
+                "<6L",
+                0xAAA15550,
+                0xAAA0D550,
+                0x00010000,
+                0x00008000,
+                0x0000800F,
+                0x001E8000,
+            )
+        )
+
+    node.start()
+    session.reconnect()
+
+
+def detects_corruption(session, function, *res):
+    """Assert that verify_heapam output matches each corruption regex."""
+    result = session.query_tuples(f"SELECT * FROM {function}")
+    for regex in res:
+        assert regex.search(result), \
+            f"expected /{regex.pattern}/ in:\n{result}"
+
+
+def detects_heap_corruption(session, function):
+    """Assert verify_heapam reports the expected heap corruption messages."""
+    detects_corruption(session, function, *_HEAP_CORRUPTION_RES)
+
+
+def detects_no_corruption(session, function):
+    """Assert verify_heapam reports no corruption (empty output)."""
+    result = session.query_tuples(f"SELECT * FROM {function}")
+    assert result == "", f"expected no corruption, got:\n{result}"
+
+
+def check_all_options_uncorrupted(session, relname):
+    """Check various options are stable and report no corruption.
+
+    The relname *must* be an uncorrupted table, or this will fail.
+    """
+    for stop in ("true", "false"):
+        for check_toast in ("true", "false"):
+            for skip in ("'none'", "'all-frozen'", "'all-visible'"):
+                for startblock in ("NULL", "0"):
+                    for endblock in ("NULL", "0"):
+                        opts = (
+                            f"on_error_stop := {stop}, "
+                            f"check_toast := {check_toast}, "
+                            f"skip := {skip}, "
+                            f"startblock := {startblock}, "
+                            f"endblock := {endblock}"
+                        )
+                        detects_no_corruption(
+                            session, f"verify_heapam('{relname}', {opts})"
+                        )
+
+
+def test_001_verify_heapam(create_pg):
+    #
+    # Test set-up
+    #
+    node = create_pg("test", start=False, initdb_extra=["--no-data-checksums"])
+    node.append_conf("autovacuum=off")
+    node.start()
+    session = node.session()
+
+    session.do("CREATE EXTENSION amcheck")
+
+    #
+    # Check a table with data loaded but no corruption, freezing, etc.
+    #
+    fresh_test_table(session, "test")
+    check_all_options_uncorrupted(session, "test")
+
+    #
+    # Check a corrupt table
+    #
+    fresh_test_table(session, "test")
+    corrupt_first_page(node, session, "test")
+    detects_heap_corruption(session, "verify_heapam('test')")
+    detects_heap_corruption(session, "verify_heapam('test', skip := 'all-visible')")
+    detects_heap_corruption(session, "verify_heapam('test', skip := 'all-frozen')")
+    detects_heap_corruption(session, "verify_heapam('test', check_toast := false)")
+    detects_heap_corruption(
+        session, "verify_heapam('test', startblock := 0, endblock := 0)"
+    )
+
+    #
+    # Check a corrupt table with all-frozen data
+    #
+    fresh_test_table(session, "test")
+    session.do("VACUUM (FREEZE, DISABLE_PAGE_SKIPPING) test")
+    detects_no_corruption(session, "verify_heapam('test')")
+    corrupt_first_page(node, session, "test")
+    detects_heap_corruption(session, "verify_heapam('test')")
+    detects_no_corruption(session, "verify_heapam('test', skip := 'all-frozen')")
+
+    #
+    # Check a sequence with no corruption.  The current implementation of
+    # sequences doesn't require its own test setup, since sequences are really
+    # just heap tables under-the-hood.  To guard against future implementation
+    # changes made without remembering to update verify_heapam, we create and
+    # exercise a sequence, checking along the way that it passes corruption
+    # checks.
+    #
+    fresh_test_sequence(session, "test_seq")
+    check_all_options_uncorrupted(session, "test_seq")
+    advance_test_sequence(session, "test_seq")
+    check_all_options_uncorrupted(session, "test_seq")
+    set_test_sequence(session, "test_seq")
+    check_all_options_uncorrupted(session, "test_seq")
+    reset_test_sequence(session, "test_seq")
+    check_all_options_uncorrupted(session, "test_seq")