Add tests to ensure lazy imports are lazy and fix sqlite3's main

Author: hugovk

Lib/sqlite3/__main__.py

@@ -15,14 +15,16 @@
 from ._completer import completer
 
 
-def execute(c, sql, suppress_errors=True, theme=theme_no_color):
+def execute(c, sql, suppress_errors=True, theme=None):
     """Helper that wraps execution of SQL code.
 
     This is used both by the REPL and by direct execution from the CLI.
 
     'c' may be a cursor or a connection.
     'sql' is the SQL string to execute.
     """
+    if theme is None:
+        theme = theme_no_color
 
     try:
         for row in c.execute(sql):

Lib/test/test_difflib.py

@@ -1,5 +1,7 @@
 import difflib
+from test import support
 from test.support import findfile, force_colorized
+from test.support.import_helper import ensure_lazy_imports
 import unittest
 import doctest
 import sys
@@ -644,6 +646,12 @@ def setUpModule():
     difflib.HtmlDiff._default_prefix = 0
 
 
+class LazyImportTest(unittest.TestCase):
+    @support.cpython_only
+    def test_lazy_import(self):
+        ensure_lazy_imports("difflib", {"_colorize"})
+
+
 def load_tests(loader, tests, pattern):
     tests.addTest(doctest.DocTestSuite(difflib))
     return tests

Lib/test/test_json/test_tool.py

@@ -8,6 +8,7 @@
 
 from test import support
 from test.support import force_colorized, force_not_colorized, os_helper
+from test.support.import_helper import ensure_lazy_imports
 from test.support.script_helper import assert_python_ok
 
 from _colorize import get_theme
@@ -334,5 +335,11 @@ class TestTool(TestMain):
     module = 'json.tool'
 
 
+class LazyImportTest(unittest.TestCase):
+    @support.cpython_only
+    def test_lazy_import(self):
+        ensure_lazy_imports("json.tool", {"_colorize"})
+
+
 if __name__ == "__main__":
     unittest.main()

Lib/test/test_pdb.py

@@ -22,7 +22,7 @@
 from io import StringIO
 from test import support
 from test.support import has_socket_support, os_helper
-from test.support.import_helper import import_module
+from test.support.import_helper import ensure_lazy_imports, import_module
 from test.support.pty_helper import run_pty, FakeInput
 from test.support.script_helper import kill_python
 from unittest.mock import patch
@@ -5306,5 +5306,11 @@ def tearDown(test):
     return tests
 
 
+class LazyImportTest(unittest.TestCase):
+    @support.cpython_only
+    def test_lazy_import(self):
+        ensure_lazy_imports("pdb", {"_colorize"})
+
+
 if __name__ == '__main__':
     unittest.main()

Lib/test/test_sqlite3/test_cli.py

@@ -7,13 +7,14 @@
 import os
 
 from sqlite3.__main__ import main as cli
-from test.support.import_helper import import_module
+from test.support.import_helper import ensure_lazy_imports, import_module
 from test.support.os_helper import TESTFN, unlink
 from test.support.pty_helper import run_pty
 from test.support import (
     captured_stdout,
     captured_stderr,
     captured_stdin,
+    cpython_only,
     force_not_colorized_test_class,
     requires_subprocess,
     verbose,
@@ -437,6 +438,11 @@ def test_complete_no_input(self):
             raise
 
 
+class LazyImportTest(unittest.TestCase):
+    @cpython_only
+    def test_lazy_import(self):
+        ensure_lazy_imports("sqlite3.__main__", {"_colorize"})
+
 
 if __name__ == "__main__":
     unittest.main()

Lib/test/test_traceback.py

@@ -23,7 +23,7 @@
                           requires_subprocess, os_helper)
 from test.support.os_helper import TESTFN, temp_dir, unlink
 from test.support.script_helper import assert_python_ok, assert_python_failure, make_script
-from test.support.import_helper import forget
+from test.support.import_helper import ensure_lazy_imports, forget
 from test.support import force_not_colorized, force_not_colorized_test_class
 
 import json
@@ -5543,5 +5543,11 @@ def test_suggestion_still_works_for_non_lazy_attributes(self):
         self.assertNotIn(b"BAR_MODULE_LOADED", stdout)
 
 
+class LazyImportTest(unittest.TestCase):
+    @support.cpython_only
+    def test_lazy_import(self):
+        ensure_lazy_imports("traceback", {"_colorize"})
+
+
 if __name__ == "__main__":
     unittest.main()