[Jython-checkins] jython: Update test_support.

[frank.wierzbicki]

http://hg.python.org/jython/rev/b2cda5e87c25
changeset:   6325:b2cda5e87c25
user:        Frank Wierzbicki <fwierzbicki at gmail.com>
date:        Mon Mar 12 13:29:09 2012 -0700
summary:
  Update test_support.

files:
  .hgsubstate              |   2 +-
  Lib/test/test_support.py |  94 +++++++++++++++++++++++++++-
  2 files changed, 94 insertions(+), 2 deletions(-)


diff --git a/.hgsubstate b/.hgsubstate
--- a/.hgsubstate
+++ b/.hgsubstate
@@ -1,1 +1,1 @@
-88766 CPythonLib
+88741 CPythonLib
diff --git a/Lib/test/test_support.py b/Lib/test/test_support.py
--- a/Lib/test/test_support.py
+++ b/Lib/test/test_support.py
@@ -11,6 +11,7 @@
 import shutil
 import warnings
 import unittest
+import importlib
 import re
 
 __all__ = ["Error", "TestFailed", "TestSkipped", "ResourceDenied", "import_module",
@@ -24,7 +25,7 @@
            "captured_stdout", "TransientResource", "transient_internet",
            "run_with_locale", "set_memlimit", "bigmemtest", "bigaddrspacetest",
            "BasicTestRunner", "run_unittest", "run_doctest", "threading_setup",
-           "threading_cleanup", "reap_children"]
+           "import_fresh_module", "threading_cleanup", "reap_children"]
 
 class Error(Exception):
     """Base class for regression test exceptions."""
@@ -50,6 +51,21 @@
     and unexpected skips.
     """
 
+ at contextlib.contextmanager
+def _ignore_deprecated_imports(ignore=True):
+    """Context manager to suppress package and module deprecation
+    warnings when importing them.
+
+    If ignore is False, this context manager has no effect."""
+    if ignore:
+        with warnings.catch_warnings():
+            warnings.filterwarnings("ignore", ".+ (module|package)",
+                                    DeprecationWarning)
+            yield
+    else:
+        yield
+
+
 def import_module(name, deprecated=False):
     """Import the module to be tested, raising TestSkipped if it is not
     available."""
@@ -64,6 +80,72 @@
         else:
             return module
 
+
+def _save_and_remove_module(name, orig_modules):
+    """Helper function to save and remove a module from sys.modules
+
+       Raise ImportError if the module can't be imported."""
+    # try to import the module and raise an error if it can't be imported
+    if name not in sys.modules:
+        __import__(name)
+        del sys.modules[name]
+    for modname in list(sys.modules):
+        if modname == name or modname.startswith(name + '.'):
+            orig_modules[modname] = sys.modules[modname]
+            del sys.modules[modname]
+
+
+def _save_and_block_module(name, orig_modules):
+    """Helper function to save and block a module in sys.modules
+
+       Return True if the module was in sys.modules, False otherwise."""
+    saved = True
+    try:
+        orig_modules[name] = sys.modules[name]
+    except KeyError:
+        saved = False
+    sys.modules[name] = None
+    return saved
+
+
+def import_fresh_module(name, fresh=(), blocked=(), deprecated=False):
+    """Imports and returns a module, deliberately bypassing the sys.modules cache
+    and importing a fresh copy of the module. Once the import is complete,
+    the sys.modules cache is restored to its original state.
+
+    Modules named in fresh are also imported anew if needed by the import.
+    If one of these modules can't be imported, None is returned.
+
+    Importing of modules named in blocked is prevented while the fresh import
+    takes place.
+
+    If deprecated is True, any module or package deprecation messages
+    will be suppressed."""
+    # NOTE: test_heapq, test_json, and test_warnings include extra sanity
+    # checks to make sure that this utility function is working as expected
+    with _ignore_deprecated_imports(deprecated):
+        # Keep track of modules saved for later restoration as well
+        # as those which just need a blocking entry removed
+        orig_modules = {}
+        names_to_remove = []
+        _save_and_remove_module(name, orig_modules)
+        try:
+            for fresh_name in fresh:
+                _save_and_remove_module(fresh_name, orig_modules)
+            for blocked_name in blocked:
+                if not _save_and_block_module(blocked_name, orig_modules):
+                    names_to_remove.append(blocked_name)
+            fresh_module = importlib.import_module(name)
+        except ImportError:
+            fresh_module = None
+        finally:
+            for orig_name, module in orig_modules.items():
+                sys.modules[orig_name] = module
+            for name_to_remove in names_to_remove:
+                del sys.modules[name_to_remove]
+        return fresh_module
+
+
 verbose = 1              # Flag set to 0 by regrtest.py
 use_resources = None     # Flag set to [] by regrtest.py
 junit_xml_dir = None     # Option set by regrtest.py
@@ -951,3 +1033,13 @@
                     break
             except:
                 break
+
+def strip_python_stderr(stderr):
+    """Strip the stderr of a Python process from potential debug output
+    emitted by the interpreter.
+
+    This will typically be run on the result of the communicate() method
+    of a subprocess.Popen object.
+    """
+    stderr = re.sub(br"\[\d+ refs\]\r?\n?$", b"", stderr).strip()
+    return stderr

-- 
Repository URL: http://hg.python.org/jython