tests: add unit test infrastructure

pytest-based test suite with fixtures for database testing.
Covers misc.py utilities, dbs.py operations, and fetch.py validation.
Includes mock_network.py for future network testing.

tests/conftest.py

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+# -*- coding: utf-8 -*-
+"""Shared pytest fixtures for PPF tests."""
+from __future__ import print_function
+
+import os
+import sys
+import tempfile
+import shutil
+
+import pytest
+
+# Add parent directory to path for imports
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+import mysqlite
+import dbs
+import misc
+
+
+@pytest.fixture(autouse=True)
+def mock_logging(monkeypatch):
+    """Mock _log to avoid Python 2 print syntax errors in Python 3.
+
+    Must patch in both misc and dbs modules since dbs uses 'from misc import _log'.
+    """
+    def noop_log(msg, level='info'):
+        pass
+    monkeypatch.setattr(misc, '_log', noop_log)
+    monkeypatch.setattr(dbs, '_log', noop_log)
+
+
+@pytest.fixture
+def temp_db():
+    """Create a temporary SQLite database for testing.
+
+    Yields a tuple of (sqlite_wrapper, db_path).
+    Database and file are cleaned up after test.
+    """
+    fd, db_path = tempfile.mkstemp(suffix='.sqlite')
+    os.close(fd)
+
+    sqlite = mysqlite.mysqlite(db_path)
+
+    yield sqlite, db_path
+
+    # Cleanup
+    sqlite.close()
+    if os.path.exists(db_path):
+        os.unlink(db_path)
+
+
+@pytest.fixture
+def proxy_db(temp_db):
+    """Create a temporary database with proxylist table initialized.
+
+    Yields a tuple of (sqlite_wrapper, db_path).
+    """
+    sqlite, db_path = temp_db
+    dbs.create_table_if_not_exists(sqlite, 'proxylist')
+    yield sqlite, db_path
+
+
+@pytest.fixture
+def uri_db(temp_db):
+    """Create a temporary database with uris table initialized.
+
+    Yields a tuple of (sqlite_wrapper, db_path).
+    """
+    sqlite, db_path = temp_db
+    dbs.create_table_if_not_exists(sqlite, 'uris')
+    yield sqlite, db_path
+
+
+@pytest.fixture
+def full_db(temp_db):
+    """Create a temporary database with both proxylist and uris tables.
+
+    Yields a tuple of (sqlite_wrapper, db_path).
+    """
+    sqlite, db_path = temp_db
+    dbs.create_table_if_not_exists(sqlite, 'proxylist')
+    dbs.create_table_if_not_exists(sqlite, 'uris')
+    yield sqlite, db_path
+
+
+@pytest.fixture
+def temp_dir():
+    """Create a temporary directory for testing.
+
+    Yields the directory path. Cleaned up after test.
+    """
+    dirpath = tempfile.mkdtemp()
+    yield dirpath
+    shutil.rmtree(dirpath, ignore_errors=True)
+
+
+@pytest.fixture
+def sample_proxies():
+    """Return a list of sample proxy strings for testing."""
+    return [
+        '1.2.3.4:8080',
+        '5.6.7.8:3128',
+        '9.10.11.12:1080',
+    ]
+
+
+@pytest.fixture
+def sample_private_ips():
+    """Return a list of private/reserved IP proxies that should be rejected."""
+    return [
+        '10.0.0.1:8080',        # Private class A
+        '172.16.0.1:8080',      # Private class B
+        '192.168.1.1:8080',     # Private class C
+        '127.0.0.1:8080',       # Loopback
+        '169.254.1.1:8080',     # Link-local
+        '224.0.0.1:8080',       # Multicast
+        '100.64.0.1:8080',      # CGNAT
+    ]
+
+
+@pytest.fixture
+def sample_cdn_ips():
+    """Return a list of CDN IP proxies that should be filtered."""
+    return [
+        '141.101.1.1:8080',     # Cloudflare
+        '151.101.1.1:8080',     # Fastly
+        '23.32.1.1:8080',       # Akamai
+        '13.32.1.1:8080',       # AWS CloudFront
+    ]