gh-109625: Move _ready_to_import() from test_import to support.import_helper (#109626)

1 files changed, 24 insertions, 1 deletions

diff --git a/Lib/test/support/import_helper.py b/Lib/test/support/import_helper.py
index 67f18e5..3d804f2 100644
--- a/Lib/test/support/import_helper.py
+++ b/Lib/test/support/import_helper.py
@@ -8,7 +8,7 @@ import sys
 import unittest
 import warnings
 
-from .os_helper import unlink
+from .os_helper import unlink, temp_dir
 
 
 @contextlib.contextmanager
@@ -274,3 +274,26 @@ def mock_register_at_fork(func):
     # memory.
     from unittest import mock
     return mock.patch('os.register_at_fork', create=True)(func)
+
+
+@contextlib.contextmanager
+def ready_to_import(name=None, source=""):
+    from test.support import script_helper
+
+    # 1. Sets up a temporary directory and removes it afterwards
+    # 2. Creates the module file
+    # 3. Temporarily clears the module from sys.modules (if any)
+    # 4. Reverts or removes the module when cleaning up
+    name = name or "spam"
+    with temp_dir() as tempdir:
+        path = script_helper.make_script(tempdir, name, source)
+        old_module = sys.modules.pop(name, None)
+        try:
+            sys.path.insert(0, tempdir)
+            yield name, path
+            sys.path.remove(tempdir)
+        finally:
+            if old_module is not None:
+                sys.modules[name] = old_module
+            else:
+                sys.modules.pop(name, None)