Merged in bubenkoff/pytest/329-skipif-requires-expression-as-a-string (pull request #43)

re #329 add test for skipif failure when you pass boolean without the reason. add emphasize to the docs.

doc/en/skipping.txt

@@ -10,11 +10,11 @@ or that you expect to fail you can mark them accordingly or you
 may call helper functions during execution of setup or test functions.
 
 A *skip* means that you expect your test to pass unless the environment
-(e.g. wrong Python interpreter, missing dependency) prevents it to run.  
+(e.g. wrong Python interpreter, missing dependency) prevents it to run.
 And *xfail* means that your test can run but you expect it to fail
 because there is an implementation problem.
 
-py.test counts and lists *skip* and *xfail* tests separately. Detailed 
+py.test counts and lists *skip* and *xfail* tests separately. Detailed
 information about skipped/xfailed tests is not shown by default to avoid
 cluttering the output.  You can use the ``-r`` option to see details
 corresponding to the "short" letters shown in the test progress::
@@ -35,15 +35,16 @@ Here is an example of marking a test function to be skipped
 when run on a Python3.3 interpreter::
 
     import sys
-    @pytest.mark.skipif(sys.version_info >= (3,3), 
+    @pytest.mark.skipif(sys.version_info >= (3,3),
                         reason="requires python3.3")
     def test_function():
         ...
 
 During test function setup the condition ("sys.version_info >= (3,3)") is
 checked.  If it evaluates to True, the test function will be skipped
-with the specified reason.  Note that pytest enforces specifying a reason 
+with the specified reason.  Note that pytest enforces specifying a reason
 in order to report meaningful "skip reasons" (e.g. when using ``-rs``).
+If the condition is a string, it will be evaluated as python expression.
 
 You can share skipif markers between modules.  Consider this test module::
 
@@ -69,7 +70,7 @@ For larger test suites it's usually a good idea to have one file
 where you define the markers which you then consistently apply
 throughout your test suite.
 
-Alternatively, the pre pytest-2.4 way to specify `condition strings <condition strings>`_ instead of booleans will remain fully supported in future 
+Alternatively, the pre pytest-2.4 way to specify `condition strings <condition strings>`_ instead of booleans will remain fully supported in future
 versions of pytest.  It couldn't be easily used for importing markers
 between test modules so it's no longer advertised as the primary method.
 
@@ -78,10 +79,10 @@ Skip all test functions of a class or module
 ---------------------------------------------
 
 As with all function :ref:`marking <mark>` you can skip test functions at the
-`whole class- or module level`_.  If your code targets python2.6 or above you 
+`whole class- or module level`_.  If your code targets python2.6 or above you
 use the skipif decorator (and any other marker) on classes::
 
-    @pytest.mark.skipif(sys.platform == 'win32', 
+    @pytest.mark.skipif(sys.platform == 'win32',
                         reason="requires windows")
     class TestPosixCalls:
 
@@ -102,7 +103,7 @@ you can set the ``pytestmark`` attribute of a class::
             "will not be setup or run under 'win32' platform"
 
 As with the class-decorator, the ``pytestmark`` special name tells
-py.test to apply it to each test function in the class.  
+py.test to apply it to each test function in the class.
 
 If you want to skip all test functions of a module, you must use
 the ``pytestmark`` name on the global level::
@@ -142,7 +143,7 @@ as if it weren't marked at all.
 As with skipif_ you can also mark your expectation of a failure
 on a particular platform::
 
-    @pytest.mark.xfail(sys.version_info >= (3,3), 
+    @pytest.mark.xfail(sys.version_info >= (3,3),
                        reason="python3.3 api changes")
     def test_function():
         ...
@@ -159,12 +160,12 @@ Running it with the report-on-xfail option gives this output::
     =========================== test session starts ============================
     platform linux2 -- Python 2.7.3 -- pytest-2.3.5
     collected 6 items
-    
+
     xfail_demo.py xxxxxx
     ========================= short test summary info ==========================
     XFAIL xfail_demo.py::test_hello
     XFAIL xfail_demo.py::test_hello2
-      reason: [NOTRUN] 
+      reason: [NOTRUN]
     XFAIL xfail_demo.py::test_hello3
       condition: hasattr(os, 'sep')
     XFAIL xfail_demo.py::test_hello4
@@ -173,7 +174,7 @@ Running it with the report-on-xfail option gives this output::
       condition: pytest.__version__[0] != "17"
     XFAIL xfail_demo.py::test_hello6
       reason: reason
-    
+
     ======================== 6 xfailed in 0.05 seconds =========================
 
 .. _`skip/xfail with parametrize`:
@@ -202,7 +203,7 @@ test instances when using parametrize:
 Imperative xfail from within a test or setup function
 ------------------------------------------------------
 
-If you cannot declare xfail- of skipif conditions at import 
+If you cannot declare xfail- of skipif conditions at import
 time you can also imperatively produce an according outcome
 imperatively, in test or setup code::
 
@@ -227,7 +228,7 @@ version number of a library::
 
     docutils = pytest.importorskip("docutils", minversion="0.3")
 
-The version will be read from the specified 
+The version will be read from the specified
 module's ``__version__`` attribute.
 
 
@@ -244,18 +245,18 @@ to use strings::
     def test_function():
         ...
 
-During test function setup the skipif condition is evaluated by calling 
-``eval('sys.version_info >= (3,0)', namespace)``.  The namespace contains 
+During test function setup the skipif condition is evaluated by calling
+``eval('sys.version_info >= (3,0)', namespace)``.  The namespace contains
 all the module globals, and ``os`` and ``sys`` as a minimum.
 
-Since pytest-2.4 `condition booleans`_ are considered preferable 
+Since pytest-2.4 `condition booleans`_ are considered preferable
 because markers can then be freely imported between test modules.
 With strings you need to import not only the marker but all variables
 everything used by the marker, which violates encapsulation.
 
 The reason for specifying the condition as a string was that py.test can
-report a summary of skip conditions based purely on the condition string.  
-With conditions as booleans you are required to specify a ``reason`` string.  
+report a summary of skip conditions based purely on the condition string.
+With conditions as booleans you are required to specify a ``reason`` string.
 
 Note that string conditions will remain fully supported and you are free
 to use them if you have no need for cross-importing markers.
@@ -266,7 +267,7 @@ dictionary which is constructed as follows:
 
 * the namespace is initialized by putting the ``sys`` and ``os`` modules
   and the pytest ``config`` object into it.
-  
+
 * updated with the module globals of the test function for which the
   expression is applied.
 

testing/test_skipping.py

@@ -100,6 +100,18 @@ class TestEvaluator:
         expl = ev.getexplanation()
         assert expl == "condition: not hasattr(os, 'murks')"
 
+    def test_marked_skip_with_not_string(self, testdir):
+        item = testdir.getitem("""
+            import pytest
+            @pytest.mark.skipif(False)
+            def test_func():
+                pass
+        """)
+        ev = MarkEvaluator(item, 'skipif')
+        with pytest.raises(pytest.fail.Exception) as exc:
+            assert ev.istrue()
+        assert """Failed: you need to specify reason=STRING when using booleans as conditions.""" in exc.value.msg
+
     def test_skipif_class(self, testdir):
         item, = testdir.getitems("""
             import pytest