gh-112730: Make the test suite resilient to color-activation environment variables (#117672)

Lib/test/test_exceptions.py

@@ -12,7 +12,8 @@ from textwrap import dedent
 from test.support import (captured_stderr, check_impl_detail,
                           cpython_only, gc_collect,
                           no_tracing, script_helper,
-                          SuppressCrashReport)
+                          SuppressCrashReport,
+                          force_not_colorized)
 from test.support.import_helper import import_module
 from test.support.os_helper import TESTFN, unlink
 from test.support.warnings_helper import check_warnings
@@ -41,6 +42,7 @@ class BrokenStrException(Exception):
 
 # XXX This is not really enough, each *operation* should be tested!
 
+
 class ExceptionTests(unittest.TestCase):
 
     def raise_catch(self, exc, excname):
@@ -1994,6 +1996,7 @@ class AssertionErrorTests(unittest.TestCase):
         _rc, _out, err = script_helper.assert_python_failure('-Wd', '-X', 'utf8', TESTFN)
         return err.decode('utf-8').splitlines()
 
+    @force_not_colorized
     def test_assertion_error_location(self):
         cases = [
             ('assert None',
@@ -2070,6 +2073,7 @@ class AssertionErrorTests(unittest.TestCase):
                 result = self.write_source(source)
                 self.assertEqual(result[-3:], expected)
 
+    @force_not_colorized
     def test_multiline_not_highlighted(self):
         cases = [
             ("""
@@ -2102,6 +2106,7 @@ class AssertionErrorTests(unittest.TestCase):
 
 
 class SyntaxErrorTests(unittest.TestCase):
+    @force_not_colorized
     def test_range_of_offsets(self):
         cases = [
             # Basic range from 2->7