get py.test to run at least basically on top of jython

* allow and document calling of monkeypatch.undo() from a test
* default to 'sys' on platforms there no 'os.dup' is available
* use "compile" to perform "tryparsing" checks

--HG--
branch : trunk

.hgignore

@@ -11,6 +11,7 @@ syntax:glob
 *.pyo
 *.swp
 *.html
+*.class
 
 build/
 py.egg-info

py/code/source.py

@@ -157,14 +157,13 @@ class Source(object):
         """ return True if source is parseable, heuristically
             deindenting it by default. 
         """
-        import parser
         if deindent:
             source = str(self.deindent())
         else:
             source = str(self)
         try:
-            parser.suite(source+'\n')
-        except (parser.ParserError, SyntaxError):
+            compile(source+'\n', "x", "exec")
+        except SyntaxError:
             return False
         else:
             return True

py/test/plugin/pytest_capture.py

@@ -85,6 +85,7 @@ argument which offers the same interface.
 """
 
 import py
+import os
 
 def pytest_addoption(parser):
     group = parser.getgroup("general")
@@ -131,11 +132,15 @@ class CaptureManager:
 
     def _getmethod(self, config, fspath):
         if config.option.capture:
-            return config.option.capture
+            method = config.option.capture
+        else:
             try: 
-            return config._conftest.rget("option_capture", path=fspath)
+                method = config._conftest.rget("option_capture", path=fspath)
             except KeyError:
-            return "fd"
+                method = "fd"
+        if method == "fd" and not hasattr(os, 'dup'): # e.g. jython 
+            method = "sys" 
+        return method
 
     def resumecapture_item(self, item):
         method = self._getmethod(item.config, item.fspath)

py/test/plugin/pytest_monkeypatch.py

@@ -4,8 +4,8 @@ safely patch object attributes, dicts and environment variables.
 Usage
 ----------------
 
-Use the `monkeypatch funcarg`_ to safely patch environment
-variables, object attributes or dictionaries.  For example, if you want
+Use the `monkeypatch funcarg`_ to safely modify or delete environment
+variables, object attributes or dictionary values.  For example, if you want
 to set the environment variable ``ENV1`` and patch the
 ``os.path.abspath`` function to return a particular value during a test
 function execution you can write it down like this:
@@ -31,6 +31,20 @@ can use this example:
         monkeypatch.setenv('PATH', 'x/y', prepend=":")
         #  x/y will be at the beginning of $PATH 
 
+calling "undo" finalization explicitely
+-----------------------------------------
+
+Usually at the end of function execution py.test will invoke
+a teardown hook which undoes the changes.  If you cannot wait
+that long you can also call finalization explicitely::
+
+    monkeypatch.undo()  
+
+This will undo previous changes.  This call consumes the
+undo stack.  Calling it a second time has no effect. 
+Within a test you can continue to use the monkeypatch 
+object, however. 
+
 .. _`monkeypatch blog post`: http://tetamap.wordpress.com/2009/03/03/monkeypatching-in-unit-tests-done-right/
 """
 
@@ -54,7 +68,7 @@ def pytest_funcarg__monkeypatch(request):
     deletion has no target. 
     """
     monkeypatch = MonkeyPatch()
-    request.addfinalizer(monkeypatch.finalize)
+    request.addfinalizer(monkeypatch.undo)
     return monkeypatch
 
 notset = object()
@@ -97,17 +111,19 @@ class MonkeyPatch:
     def delenv(self, name, raising=True):
         self.delitem(os.environ, name, raising=raising)
 
-    def finalize(self):
+    def undo(self):
         for obj, name, value in self._setattr:
             if value is not notset:
                 setattr(obj, name, value)
             else:
                 delattr(obj, name)
+        self._setattr[:] = []
         for dictionary, name, value in self._setitem:
             if value is notset:
                 del dictionary[name]
             else:
                 dictionary[name] = value
+        self._setitem[:] = []
 
 
 def test_setattr():
@@ -118,12 +134,16 @@ def test_setattr():
     assert A.x == 2
     monkeypatch.setattr(A, 'x', 3)
     assert A.x == 3
-    monkeypatch.finalize()
+    monkeypatch.undo()
     assert A.x == 1
 
+    A.x = 5
+    monkeypatch.undo() # double-undo makes no modification
+    assert A.x == 5
+
     monkeypatch.setattr(A, 'y', 3)
     assert A.y == 3
-    monkeypatch.finalize()
+    monkeypatch.undo()
     assert not hasattr(A, 'y')
      
 def test_delattr():
@@ -132,7 +152,7 @@ def test_delattr():
     monkeypatch = MonkeyPatch()
     monkeypatch.delattr(A, 'x')
     assert not hasattr(A, 'x')
-    monkeypatch.finalize()
+    monkeypatch.undo()
     assert A.x == 1
 
     monkeypatch = MonkeyPatch()
@@ -141,7 +161,7 @@ def test_delattr():
     monkeypatch.delattr(A, 'y', raising=False)
     monkeypatch.setattr(A, 'x', 5)
     assert A.x == 5
-    monkeypatch.finalize()
+    monkeypatch.undo()
     assert A.x == 1
 
 def test_setitem():
@@ -153,9 +173,12 @@ def test_setitem():
     assert d['y'] == 1700
     monkeypatch.setitem(d, 'x', 3)
     assert d['x'] == 3
-    monkeypatch.finalize()
+    monkeypatch.undo()
     assert d['x'] == 1
     assert 'y' not in d
+    d['x'] = 5
+    monkeypatch.undo()
+    assert d['x'] == 5
 
 def test_delitem():
     d = {'x': 1}
@@ -170,7 +193,7 @@ def test_delitem():
     d['hello'] = 'world'
     monkeypatch.setitem(d, 'x', 1500)
     assert d['x'] == 1500
-    monkeypatch.finalize()
+    monkeypatch.undo()
     assert d == {'hello': 'world', 'x': 1}
 
 def test_setenv():
@@ -178,7 +201,7 @@ def test_setenv():
     monkeypatch.setenv('XYZ123', 2)
     import os
     assert os.environ['XYZ123'] == "2"
-    monkeypatch.finalize()
+    monkeypatch.undo()
     assert 'XYZ123' not in os.environ
 
 def test_delenv():
@@ -187,7 +210,7 @@ def test_delenv():
     monkeypatch = MonkeyPatch()
     py.test.raises(KeyError, "monkeypatch.delenv(%r, raising=True)" % name)
     monkeypatch.delenv(name, raising=False)
-    monkeypatch.finalize()
+    monkeypatch.undo()
     os.environ[name] = "1"
     try:
         monkeypatch = MonkeyPatch()
@@ -195,7 +218,7 @@ def test_delenv():
         assert name not in os.environ 
         monkeypatch.setenv(name, "3")
         assert os.environ[name] == "3"
-        monkeypatch.finalize()
+        monkeypatch.undo()
         assert os.environ[name] == "1"
     finally:
         if name in os.environ:
@@ -208,7 +231,7 @@ def test_setenv_prepend():
     assert os.environ['XYZ123'] == "2"
     monkeypatch.setenv('XYZ123', 3, prepend="-")
     assert os.environ['XYZ123'] == "3-2"
-    monkeypatch.finalize()
+    monkeypatch.undo()
     assert 'XYZ123' not in os.environ
 
 def test_monkeypatch_plugin(testdir):

py/test/plugin/test_pytest_capture.py

@@ -2,6 +2,16 @@ import py, os, sys
 from py.__.test.plugin.pytest_capture import CaptureManager
 
 class TestCaptureManager:
+    def test_getmethod_default_no_fd(self, testdir, monkeypatch):
+        config = testdir.parseconfig(testdir.tmpdir)
+        assert config.getvalue("capture") is None
+        capman = CaptureManager()
+        monkeypatch.delattr(os, 'dup')
+        try:
+            assert capman._getmethod(config, None) == "sys" 
+        finally:
+            monkeypatch.finalize()
+
     def test_configure_per_fspath(self, testdir):
         config = testdir.parseconfig(testdir.tmpdir)
         assert config.getvalue("capture") is None