implement pytest.param

this allows a clear addition of parameterization parameters that carry along marks
instead of nesting multiple mark objects and destroying the possibility of creating
function valued parameters,
it just folders everything together into one object carrfying parameters, and the marks.

_pytest/mark.py

@@ -6,17 +6,72 @@
 from operator import attrgetter
 from .compat import imap
 
+
 def alias(name):
     return property(attrgetter(name), doc='alias for ' + name)
 
 
+class ParameterSet(namedtuple('ParameterSet', 'values, marks, id')):
+    @classmethod
+    def param(cls, *values, **kw):
+        marks = kw.pop('marks', ())
+        if isinstance(marks, MarkDecorator):
+            marks = marks,
+        else:
+            assert isinstance(marks, (tuple, list, set))
+
+        def param_extract_id(id=None):
+            return id
+
+        id = param_extract_id(**kw)
+        return cls(values, marks, id)
+
+    @classmethod
+    def extract_from(cls, parameterset, legacy_force_tuple=False):
+        """
+        :param parameterset:
+            a legacy style parameterset that may or may not be a tuple,
+            and may or may not be wrapped into a mess of mark objects
+
+        :param legacy_force_tuple:
+            enforce tuple wrapping so single argument tuple values
+            don't get decomposed and break tests
+
+        """
+
+        if isinstance(parameterset, cls):
+            return parameterset
+        if not isinstance(parameterset, MarkDecorator) and legacy_force_tuple:
+            return cls.param(parameterset)
+
+        newmarks = []
+        argval = parameterset
+        while isinstance(argval, MarkDecorator):
+            newmarks.append(MarkDecorator(Mark(
+                argval.markname, argval.args[:-1], argval.kwargs)))
+            argval = argval.args[-1]
+        assert not isinstance(argval, ParameterSet)
+        if legacy_force_tuple:
+            argval = argval,
+
+        return cls(argval, marks=newmarks, id=None)
+
+    @property
+    def deprecated_arg_dict(self):
+        return dict((mark.name, mark) for mark in self.marks)
+
+
 class MarkerError(Exception):
 
     """Error in use of a pytest marker/attribute."""
 
 
+
 def pytest_namespace():
-    return {'mark': MarkGenerator()}
+    return {
+        'mark': MarkGenerator(),
+        'param': ParameterSet.param,
+    }
 
 
 def pytest_addoption(parser):
@@ -212,6 +267,7 @@ def istestfunc(func):
     return hasattr(func, "__call__") and \
         getattr(func, "__name__", "<lambda>") != "<lambda>"
 
+
 class MarkDecorator(object):
     """ A decorator for test functions and test classes.  When applied
     it will create :class:`MarkInfo` objects which may be
@@ -257,8 +313,11 @@ def __init__(self, mark):
     def markname(self):
         return self.name # for backward-compat (2.4.1 had this attr)
 
+    def __eq__(self, other):
+        return self.mark == other.mark
+
     def __repr__(self):
-        return "<MarkDecorator %r>" % self.mark
+        return "<MarkDecorator %r>" % (self.mark,)
 
     def __call__(self, *args, **kwargs):
         """ if passed a single callable argument: decorate it with mark info.
@@ -291,19 +350,7 @@ def __call__(self, *args, **kwargs):
         return self.__class__(self.mark.combined_with(mark))
 
 
-def extract_argvalue(maybe_marked_args):
-    # TODO: incorrect mark data, the old code wanst able to collect lists
-    # individual parametrized argument sets can be wrapped in a series
-    # of markers in which case we unwrap the values and apply the mark
-    # at Function init
-    newmarks = {}
-    argval = maybe_marked_args
-    while isinstance(argval, MarkDecorator):
-        newmark = MarkDecorator(Mark(
-            argval.markname, argval.args[:-1], argval.kwargs))
-        newmarks[newmark.name] = newmark
-        argval = argval.args[-1]
-    return argval, newmarks
+
 
 
 class Mark(namedtuple('Mark', 'name, args, kwargs')):

_pytest/python.py

@@ -788,36 +788,35 @@ def parametrize(self, argnames, argvalues, indirect=False, ids=None,
             to set a dynamic scope using test context or configuration.
         """
         from _pytest.fixtures import scope2index
-        from _pytest.mark import extract_argvalue
+        from _pytest.mark import ParameterSet
         from py.io import saferepr
 
-        unwrapped_argvalues = []
-        newkeywords = []
-        for maybe_marked_args in argvalues:
-            argval, newmarks = extract_argvalue(maybe_marked_args)
-            unwrapped_argvalues.append(argval)
-            newkeywords.append(newmarks)
-        argvalues = unwrapped_argvalues
-
         if not isinstance(argnames, (tuple, list)):
             argnames = [x.strip() for x in argnames.split(",") if x.strip()]
-            if len(argnames) == 1:
-                argvalues = [(val,) for val in argvalues]
-        if not argvalues:
-            argvalues = [(NOTSET,) * len(argnames)]
-            # we passed a empty list to parameterize, skip that test
-            #
+            force_tuple = len(argnames) == 1
+        else:
+            force_tuple = False
+        parameters = [
+            ParameterSet.extract_from(x, legacy_force_tuple=force_tuple)
+            for x in argvalues]
+        del argvalues
+
+
+        if not parameters:
             fs, lineno = getfslineno(self.function)
-            newmark = pytest.mark.skip(
-                reason="got empty parameter set %r, function %s at %s:%d" % (
-                    argnames, self.function.__name__, fs, lineno))
-            newkeywords = [{newmark.markname: newmark}]
+            reason = "got empty parameter set %r, function %s at %s:%d" % (
+                    argnames, self.function.__name__, fs, lineno)
+            mark = pytest.mark.skip(reason=reason)
+            parameters.append(ParameterSet(
+                values=(NOTSET,) * len(argnames),
+                marks=[mark],
+                id=None,
+            ))
 
         if scope is None:
             scope = _find_parametrized_scope(argnames, self._arg2fixturedefs, indirect)
 
-        scopenum = scope2index(
-            scope, descr='call to {0}'.format(self.parametrize))
+        scopenum = scope2index(scope, descr='call to {0}'.format(self.parametrize))
         valtypes = {}
         for arg in argnames:
             if arg not in self.fixturenames:
@@ -845,22 +844,22 @@ def parametrize(self, argnames, argvalues, indirect=False, ids=None,
             idfn = ids
             ids = None
         if ids:
-            if len(ids) != len(argvalues):
-                raise ValueError('%d tests specified with %d ids' %(
-                                 len(argvalues), len(ids)))
+            if len(ids) != len(parameters):
+                raise ValueError('%d tests specified with %d ids' % (
+                                 len(parameters), len(ids)))
             for id_value in ids:
                 if id_value is not None and not isinstance(id_value, py.builtin._basestring):
                     msg = 'ids must be list of strings, found: %s (type: %s)'
                     raise ValueError(msg % (saferepr(id_value), type(id_value).__name__))
-        ids = idmaker(argnames, argvalues, idfn, ids, self.config)
+        ids = idmaker(argnames, parameters, idfn, ids, self.config)
         newcalls = []
         for callspec in self._calls or [CallSpec2(self)]:
-            elements = zip(ids, argvalues, newkeywords, count())
-            for a_id, valset, keywords, param_index in elements:
-                assert len(valset) == len(argnames)
+            elements = zip(ids, parameters, count())
+            for a_id, param, param_index in elements:
+                assert len(param.values) == len(argnames)
                 newcallspec = callspec.copy(self)
-                newcallspec.setmulti(valtypes, argnames, valset, a_id,
-                                     keywords, scopenum, param_index)
+                newcallspec.setmulti(valtypes, argnames, param.values, a_id,
+                                     param.deprecated_arg_dict, scopenum, param_index)
                 newcalls.append(newcallspec)
         self._calls = newcalls
 
@@ -959,17 +958,19 @@ def _idval(val, argname, idx, idfn, config=None):
         return val.__name__
     return str(argname)+str(idx)
 
-def _idvalset(idx, valset, argnames, idfn, ids, config=None):
+def _idvalset(idx, parameterset, argnames, idfn, ids, config=None):
+    if parameterset.id is not None:
+        return parameterset.id
     if ids is None or (idx >= len(ids) or ids[idx] is None):
         this_id = [_idval(val, argname, idx, idfn, config)
-                   for val, argname in zip(valset, argnames)]
+                   for val, argname in zip(parameterset.values, argnames)]
         return "-".join(this_id)
     else:
         return _escape_strings(ids[idx])
 
-def idmaker(argnames, argvalues, idfn=None, ids=None, config=None):
-    ids = [_idvalset(valindex, valset, argnames, idfn, ids, config)
-           for valindex, valset in enumerate(argvalues)]
+def idmaker(argnames, parametersets, idfn=None, ids=None, config=None):
+    ids = [_idvalset(valindex, parameterset, argnames, idfn, ids, config)
+           for valindex, parameterset in enumerate(parametersets)]
     if len(set(ids)) != len(ids):
         # The ids are not unique
         duplicates = [testid for testid in ids if ids.count(testid) > 1]

doc/en/parametrize.rst

@@ -55,27 +55,27 @@ them in turn::
 
     $ pytest
     ======= test session starts ========
-    platform linux -- Python 3.5.2, pytest-3.0.7, py-1.4.32, pluggy-0.4.0
+    platform linux -- Python 3.5.2, pytest-3.0.3, py-1.4.31, pluggy-0.4.0
     rootdir: $REGENDOC_TMPDIR, inifile:
     collected 3 items
-    
+
     test_expectation.py ..F
-    
+
     ======= FAILURES ========
     _______ test_eval[6*9-42] ________
-    
+
     test_input = '6*9', expected = 42
-    
+
         @pytest.mark.parametrize("test_input,expected", [
             ("3+5", 8),
             ("2+4", 6),
             ("6*9", 42),
         ])
         def test_eval(test_input, expected):
     >       assert eval(test_input) == expected
-    E       AssertionError: assert 54 == 42
+    E       assert 54 == 42
     E        +  where 54 = eval('6*9')
-    
+
     test_expectation.py:8: AssertionError
     ======= 1 failed, 2 passed in 0.12 seconds ========
 
@@ -94,21 +94,42 @@ for example with the builtin ``mark.xfail``::
     @pytest.mark.parametrize("test_input,expected", [
         ("3+5", 8),
         ("2+4", 6),
-        pytest.mark.xfail(("6*9", 42)),
+        pytest.param("6*9", 42,
+                     marks=pytest.mark.xfail),
     ])
     def test_eval(test_input, expected):
         assert eval(test_input) == expected
 
+.. note::
+
+  prior to version 3.1 the supported mechanism for marking values
+  used the syntax::
+
+        import pytest
+        @pytest.mark.parametrize("test_input,expected", [
+            ("3+5", 8),
+            ("2+4", 6),
+            pytest.mark.xfail(("6*9", 42),),
+        ])
+        def test_eval(test_input, expected):
+            assert eval(test_input) == expected
+
+
+  This was an initial hack to support the feature but soon was demonstrated to be incomplete,
+  broken for passing functions or applying multiple marks with the same name but different parameters.
+  The old syntax will be removed in pytest-4.0.
+
+
 Let's run this::
 
     $ pytest
     ======= test session starts ========
-    platform linux -- Python 3.5.2, pytest-3.0.7, py-1.4.32, pluggy-0.4.0
+    platform linux -- Python 3.5.2, pytest-3.0.3, py-1.4.31, pluggy-0.4.0
     rootdir: $REGENDOC_TMPDIR, inifile:
     collected 3 items
-    
+
     test_expectation.py ..x
-    
+
     ======= 2 passed, 1 xfailed in 0.12 seconds ========
 
 The one parameter set which caused a failure previously now
@@ -181,15 +202,15 @@ Let's also run with a stringinput that will lead to a failing test::
     F
     ======= FAILURES ========
     _______ test_valid_string[!] ________
-    
+
     stringinput = '!'
-    
+
         def test_valid_string(stringinput):
     >       assert stringinput.isalpha()
-    E       AssertionError: assert False
+    E       assert False
     E        +  where False = <built-in method isalpha of str object at 0xdeadbeef>()
     E        +    where <built-in method isalpha of str object at 0xdeadbeef> = '!'.isalpha
-    
+
     test_strings.py:3: AssertionError
     1 failed in 0.12 seconds