fix issue660: properly report fixture scope mismatches independent

from fixture argument ordering.

--HG--
branch : issue660

CHANGELOG

@@ -1,6 +1,11 @@
 2.7.1.dev (compared to 2.7.0)
 -----------------------------
 
+- fix issue660: properly report scope-mismatch-access errors
+  independently from ordering of fixture arguments.  Also
+  avoid the pytest internal traceback which does not provide
+  information to the user.
+
 
 2.7.0 (compared to 2.6.4)
 -----------------------------

_pytest/python.py

@@ -1356,12 +1356,7 @@ class FixtureRequest(FuncargnamesCompatAttr):
         try:
             val = cache[cachekey]
         except KeyError:
-            __tracebackhide__ = True
-            if scopemismatch(self.scope, scope):
-                raise ScopeMismatchError("You tried to access a %r scoped "
-                    "resource with a %r scoped request object" %(
-                    (scope, self.scope)))
-            __tracebackhide__ = False
+            self._check_scope(self.fixturename, self.scope, scope)
             val = setup()
             cache[cachekey] = val
             if teardown is not None:
@@ -1392,6 +1387,7 @@ class FixtureRequest(FuncargnamesCompatAttr):
                 if argname == "request":
                     class PseudoFixtureDef:
                         cached_result = (self, [0], None)
+                        scope = "function"
                     return PseudoFixtureDef
                 raise
         # remove indent to prevent the python3 exception
@@ -1435,16 +1431,7 @@ class FixtureRequest(FuncargnamesCompatAttr):
         subrequest = SubRequest(self, scope, param, param_index, fixturedef)
 
         # check if a higher-level scoped fixture accesses a lower level one
-        if scope is not None:
-            __tracebackhide__ = True
-            if scopemismatch(self.scope, scope):
-                # try to report something helpful
-                lines = subrequest._factorytraceback()
-                raise ScopeMismatchError("You tried to access the %r scoped "
-                    "fixture %r with a %r scoped request object, "
-                    "involved factories\n%s" %(
-                    (scope, argname, self.scope, "\n".join(lines))))
-            __tracebackhide__ = False
+        subrequest._check_scope(argname, self.scope, scope)
 
         # clear sys.exc_info before invoking the fixture (python bug?)
         # if its not explicitly cleared it will leak into the call
@@ -1458,6 +1445,18 @@ class FixtureRequest(FuncargnamesCompatAttr):
                                                   subrequest.node)
         return val
 
+    def _check_scope(self, argname, invoking_scope, requested_scope):
+        if argname == "request":
+            return
+        if scopemismatch(invoking_scope, requested_scope):
+            # try to report something helpful
+            lines = self._factorytraceback()
+            pytest.fail("ScopeMismatch: you tried to access the %r scoped "
+                "fixture %r with a %r scoped request object, "
+                "involved factories\n%s" %(
+                (requested_scope, argname, invoking_scope, "\n".join(lines))),
+                pytrace=False)
+
     def _factorytraceback(self):
         lines = []
         for fixturedef in self._get_fixturestack():
@@ -1518,6 +1517,7 @@ scopenum_function = scopes.index("function")
 def scopemismatch(currentscope, newscope):
     return scopes.index(newscope) > scopes.index(currentscope)
 
+
 class FixtureLookupError(LookupError):
     """ could not return a requested Fixture (missing or invalid). """
     def __init__(self, argname, request, msg=None):
@@ -1867,6 +1867,7 @@ class FixtureDef:
         for argname in self.argnames:
             fixturedef = request._get_active_fixturedef(argname)
             result, arg_cache_key, exc = fixturedef.cached_result
+            request._check_scope(argname, request.scope, fixturedef.scope)
             kwargs[argname] = result
             if argname != "request":
                 fixturedef.addfinalizer(self.finish)

testing/python/fixture.py

@@ -906,6 +906,27 @@ class TestFixtureUsages:
             "*1 error*"
         ])
 
+    def test_receives_funcargs_scope_mismatch_issue660(self, testdir):
+        testdir.makepyfile("""
+            import pytest
+            @pytest.fixture(scope="function")
+            def arg1():
+                return 1
+
+            @pytest.fixture(scope="module")
+            def arg2(arg1):
+                return arg1 + 1
+
+            def test_add(arg1, arg2):
+                assert arg2 == 2
+        """)
+        result = testdir.runpytest()
+        result.stdout.fnmatch_lines([
+            "*ScopeMismatch*involved factories*",
+            "* def arg2*",
+            "*1 error*"
+        ])
+
     def test_funcarg_parametrized_and_used_twice(self, testdir):
         testdir.makepyfile("""
             import pytest