Fix strict xfail: it should behave exactly like xfail when a test fails

_pytest/skipping.py

@@ -186,27 +186,33 @@ def pytest_runtest_setup(item):
 @pytest.mark.hookwrapper
 def pytest_pyfunc_call(pyfuncitem):
     check_xfail_no_run(pyfuncitem)
-    yield
-    evalxfail = pyfuncitem._evalxfail
-    if evalxfail.istrue() and _is_strict_xfail(evalxfail, pyfuncitem.config):
-        del pyfuncitem._evalxfail
-        explanation = evalxfail.getexplanation()
-        pytest.fail('[XPASS(strict)] ' + explanation,
-                    pytrace=False)
-
-
-def _is_strict_xfail(evalxfail, config):
-    default = config.getini('xfail_strict')
-    return evalxfail.get('strict', default)
+    outcome = yield
+    passed = outcome.excinfo is None
+    if passed:
+        check_strict_xfail(pyfuncitem)
 
 
 def check_xfail_no_run(item):
+    """check xfail(run=False)"""
     if not item.config.option.runxfail:
         evalxfail = item._evalxfail
         if evalxfail.istrue():
             if not evalxfail.get('run', True):
                 pytest.xfail("[NOTRUN] " + evalxfail.getexplanation())
 
+
+def check_strict_xfail(pyfuncitem):
+    """check xfail(strict=True) for the given PASSING test"""
+    evalxfail = pyfuncitem._evalxfail
+    if evalxfail.istrue():
+        strict_default = pyfuncitem.config.getini('xfail_strict')
+        is_strict_xfail = evalxfail.get('strict', strict_default)
+        if is_strict_xfail:
+            del pyfuncitem._evalxfail
+            explanation = evalxfail.getexplanation()
+            pytest.fail('[XPASS(strict)] ' + explanation, pytrace=False)
+
+
 @pytest.hookimpl(hookwrapper=True)
 def pytest_runtest_makereport(item, call):
     outcome = yield

testing/test_skipping.py

@@ -127,13 +127,15 @@ class TestEvaluator:
 
 
 class TestXFail:
-    def test_xfail_simple(self, testdir):
+
+    @pytest.mark.parametrize('strict', [True, False])
+    def test_xfail_simple(self, testdir, strict):
         item = testdir.getitem("""
             import pytest
-            @pytest.mark.xfail
+            @pytest.mark.xfail(strict=%s)
             def test_func():
                 assert 0
-        """)
+        """ % strict)
         reports = runtestprotocol(item, log=False)
         assert len(reports) == 3
         callreport = reports[1]
@@ -350,6 +352,23 @@ class TestXFail:
             matchline,
         ])
 
+    def test_strict_sanity(self, testdir):
+        """sanity check for xfail(strict=True): a failing test should behave
+        exactly like a normal xfail.
+        """
+        p = testdir.makepyfile("""
+            import pytest
+            @pytest.mark.xfail(reason='unsupported feature', strict=True)
+            def test_foo():
+                assert 0
+        """)
+        result = testdir.runpytest(p, '-rxX')
+        result.stdout.fnmatch_lines([
+            '*XFAIL*',
+            '*unsupported feature*',
+        ])
+        assert result.ret == 0
+
     @pytest.mark.parametrize('strict', [True, False])
     def test_strict_xfail(self, testdir, strict):
         p = testdir.makepyfile("""