move to xfail

pyupgrade/_plugins/versioned_branches.py

@@ -188,10 +188,5 @@ def visit_If(
     ):
         if node.orelse and not isinstance(node.orelse[0], ast.If):
             yield ast_to_offset(node), _fix_py3_block_else
-        elif not node.orelse and min_version == (3, 0):
-            # allow >= (3,) and > (3,) to be dedented even without
-            # an else clause, as a special cases
+        elif not node.orelse:
             yield ast_to_offset(node), _fix_py3_block
-        else:
-            # don't try to fix, e.g., >= (3, 6) if there's no else clause
-            yield ast_to_offset(node), lambda i, tokens: None

tests/features/versioned_branches_test.py

@@ -555,15 +555,6 @@ def test_fix_py3x_only_code(s, expected):
 @pytest.mark.parametrize(
     's',
     (
-        # we timidly skip `if` without `else` as it could cause a SyntaxError
-        'import sys\n'
-        'if sys.version_info >= (3, 6):\n'
-        '    pass',
-        # here's the case where it causes a SyntaxError
-        'import sys\n'
-        'if True:\n'
-        '    if sys.version_info >= (3, 6):\n'
-        '        pass\n',
         # both branches are still relevant in the following cases
         'import sys\n'
         'if sys.version_info > (3, 7):\n'
@@ -600,7 +591,25 @@ def test_fix_py3x_only_code(s, expected):
         '    3+7\n'
         'else:\n'
         '    3-6\n',
+
+        # this one *could* be fixed, it's just not implemented yet
+        # see test_no_else_py3x_only_code
+        'import sys\n'
+        'if sys.version_info >= (3, 6):\n'
+        '    pass',
     ),
 )
 def test_fix_py3x_only_noop(s):
     assert _fix_plugins(s, settings=Settings(min_version=(3, 6))) == s
+
+
+@pytest.mark.xfail(reason='not implemented')
+def test_no_else_py3x_only_code():
+
+    s = (
+        'import sys\n'
+        'if sys.version_info >= (3, 6):\n'
+        '    pass'
+    )
+    expected = 'import sys\n'
+    assert _fix_plugins(s, settings=Settings(min_version=(3, 6))) == expected