pytest mark中的skip,skipif, xfail

这些测试的过滤，或是对返回值的二重判断，

可以让测试过程更精准，测试结果更可控，

并可以更高层的应用测试脚本来保持批量化执行。

import pytest
import tasks
from tasks import Task

@pytest.fixture(autouse=True)
def initialized_tasks_db(tmpdir):
    tasks.start_tasks_db(str(tmpdir), 'tiny')

    yield

    tasks.stop_tasks_db()

@pytest.mark.skip(reason="misunderstood the API")
def test_unique_id_1():
    id_1 = tasks.unique_id()
    id_2 = tasks.unique_id()
    assert id_1 != id_2

def test_unique_id_2():
    ids = list()
    ids.append(tasks.add(Task('one')))
    ids.append(tasks.add(Task('two')))
    ids.append(tasks.add(Task('three')))
    uid = tasks.unique_id()
    assert uid not in ids

@pytest.mark.skipif(tasks.__version__ < '0.2.0',
                    reason="not supported until version 0.2.0")
def test_unique_id_3():
    id_1 = tasks.unique_id()
    id_2 = tasks.unique_id()
    assert id_1 != id_2

@pytest.mark.xfail(tasks.__version__ < '0.2.0',
                   reason="not supported until version 0.2.0")
def test_unique_id_4():
    id_1 = tasks.unique_id()
    id_2 = tasks.unique_id()
    assert id_1 != id_2

@pytest.mark.xfail()
def test_unique_id_is_a_duck():
    uid = tasks.unique_id()
    assert uid == "a duck"

@pytest.mark.xfail()
def test_unique_id_not_a_duck():
    uid = tasks.unique_id()
    assert uid != "a duck"