pytest：通过固定装置参数化测试用例

Question

如何编写 yields/returns 参数化测试参数的夹具（方法）？

比如我有一个测试如下：

@pytest.mark.parametrize(
    "input,expected", 
    [("hello", "hello"),
    ("world", "world")])
def test_get_message(self, input, expected):
    assert expected == MyClass.get_message(input)

我对以下方法感兴趣，而不是通过 @pytest.mark.parametrize 传递 input 和 expected：

@pytest.fixture(scope="session")
def test_messages(self):
    # what should I write here to return multiple 
    # test case with expected value for each?
    pass

def test_get_message(self, test_messages):
    expected = test_messages["expected"] # somehow extracted from test_messages?
    input = test_messages["input"]       # somehow extracted from test message?
    assert expected == MyClass.get_message(input)

Answer 1

要将参数移动到夹具中，您可以使用夹具参数：

@pytest.fixture(params=[("hello", "hello"),
    ("world", "world")], scope="session")
def test_messages(self, request):
    return request.param

def test_get_message(self, test_messages):
    input = test_messages[0]   
    expected = test_messages[1]
    assert expected == MyClass.get_message(input)

你也可以将参数放入一个单独的函数中（与wih parametrize相同），例如

def get_test_messages():
    return [("hello", "hello"), ("world", "world")]

@pytest.fixture(params=get_test_messages(), scope="session")
def test_messages(self, request):
    return request.param

Answer 2

对我来说，你似乎想要 return 一个字典数组：

@pytest.fixture(scope="session")
def test_messages():
    return [
        {
            "input": "hello",
            "expected": "world"
        },
        {
            "input": "hello",
            "expected": "hello"
        }
    ]

要在测试用例中使用它，您需要遍历数组：

def test_get_message(self, test_messages):
    for test_data in test_messages:
        input = test_data["input"]
        expected = test_data["expected"]
        assert input == expected

但我不确定这是否是最好的方法，因为它仍然被认为只是一个测试用例，因此它将在 output/report.

中仅显示为一个测试用例。

pytest：通过固定装置参数化测试用例

pytest: Parameterized test cases via fixtures

python

unit-testing

fixtures

pytest