#N/A: Improve how version is fetched for all shells (#920)

tests/shells/test_powershell.py

@@ -10,6 +10,11 @@ class TestPowershell(object):
     def shell(self):
         return Powershell()
 
+    @pytest.fixture(autouse=True)
+    def Popen(self, mocker):
+        mock = mocker.patch('thefuck.shells.powershell.Popen')
+        return mock
+
     def test_and_(self, shell):
         assert shell.and_('ls', 'cd') == '(ls) -and (cd)'
 
@@ -20,3 +25,20 @@ class TestPowershell(object):
 
     def test_how_to_configure(self, shell):
         assert not shell.how_to_configure().can_configure_automatically
+
+    @pytest.mark.parametrize('side_effect, expected_version, call_args', [
+        ([b'''Major  Minor  Build  Revision
+-----  -----  -----  --------
+5      1      17763  316     \n'''], 'PowerShell 5.1.17763.316', ['powershell.exe']),
+        ([IOError, b'PowerShell 6.1.2\n'], 'PowerShell 6.1.2', ['powershell.exe', 'pwsh'])])
+    def test_info(self, side_effect, expected_version, call_args, shell, Popen):
+        Popen.return_value.stdout.read.side_effect = side_effect
+        assert shell.info() == expected_version
+        assert Popen.call_count == len(call_args)
+        assert all([Popen.call_args_list[i][0][0][0] == call_arg for i, call_arg in enumerate(call_args)])
+
+    def test_get_version_error(self, shell, Popen):
+        Popen.return_value.stdout.read.side_effect = RuntimeError
+        with pytest.raises(RuntimeError):
+            shell._get_version()
+        assert Popen.call_args[0][0] == ['powershell.exe', '$PSVersionTable.PSVersion']