gh-108550: Speed up sqlite3 tests (#108551)

Refactor the CLI so we can easily invoke it and mock command-line
arguments. Adapt the CLI tests so we no longer have to launch a
separate process.

Disable the busy handler for all concurrency tests; we have full
control over the order of the SQLite C API calls, so we can safely
do this.

The sqlite3 test suite now completes ~8 times faster than before.

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

1 files changed, 6 insertions, 10 deletions

diff --git a/Lib/test/test_sqlite3/test_transactions.py b/Lib/test/test_sqlite3/test_transactions.py
index b7b231d..a3de7a7 100644
--- a/Lib/test/test_sqlite3/test_transactions.py
+++ b/Lib/test/test_sqlite3/test_transactions.py
@@ -24,7 +24,6 @@ import unittest
 import sqlite3 as sqlite
 from contextlib import contextmanager
 
-from test.support import LOOPBACK_TIMEOUT
 from test.support.os_helper import TESTFN, unlink
 from test.support.script_helper import assert_python_ok
 
@@ -32,15 +31,14 @@ from .util import memory_database
 from .util import MemoryDatabaseMixin
 
 
-TIMEOUT = LOOPBACK_TIMEOUT / 10
-
-
 class TransactionTests(unittest.TestCase):
     def setUp(self):
-        self.con1 = sqlite.connect(TESTFN, timeout=TIMEOUT)
+        # We can disable the busy handlers, since we control
+        # the order of SQLite C API operations.
+        self.con1 = sqlite.connect(TESTFN, timeout=0)
         self.cur1 = self.con1.cursor()
 
-        self.con2 = sqlite.connect(TESTFN, timeout=TIMEOUT)
+        self.con2 = sqlite.connect(TESTFN, timeout=0)
         self.cur2 = self.con2.cursor()
 
     def tearDown(self):
@@ -120,10 +118,8 @@ class TransactionTests(unittest.TestCase):
             self.cur2.execute("insert into test(i) values (5)")
 
     def test_locking(self):
-        """
-        This tests the improved concurrency with pysqlite 2.3.4. You needed
-        to roll back con2 before you could commit con1.
-        """
+        # This tests the improved concurrency with pysqlite 2.3.4. You needed
+        # to roll back con2 before you could commit con1.
         self.cur1.execute("create table test(i)")
         self.cur1.execute("insert into test(i) values (5)")
         with self.assertRaises(sqlite.OperationalError):