Question

在yaml文件中指定测试的基本示例

下面是一个例子 conftest.py （摘自Ali Afshar的特殊用途 pytest-yamlwsgi 插件）。这个 conftest.py 将收集 test*.yaml 文件并将以自定义测试的形式执行yaml格式的内容：

# content of conftest.py
import pytest


def pytest_collect_file(parent, path):
    if path.ext == ".yaml" and path.basename.startswith("test"):
        return YamlFile.from_parent(parent, fspath=path)


class YamlFile(pytest.File):
    def collect(self):
        # We need a yaml parser, e.g. PyYAML.
        import yaml

        raw = yaml.safe_load(self.fspath.open())
        for name, spec in sorted(raw.items()):
            yield YamlItem.from_parent(self, name=name, spec=spec)


class YamlItem(pytest.Item):
    def __init__(self, name, parent, spec):
        super().__init__(name, parent)
        self.spec = spec

    def runtest(self):
        for name, value in sorted(self.spec.items()):
            # Some custom test execution (dumb example follows).
            if name != value:
                raise YamlException(self, name, value)

    def repr_failure(self, excinfo):
        """Called when self.runtest() raises an exception."""
        if isinstance(excinfo.value, YamlException):
            return "\n".join(
                [
                    "usecase execution failed",
                    "   spec failed: {1!r}: {2!r}".format(*excinfo.value.args),
                    "   no further details known at this point.",
                ]
            )

    def reportinfo(self):
        return self.fspath, 0, f"usecase: {self.name}"


class YamlException(Exception):
    """Custom exception for error reporting."""

您可以创建一个简单的示例文件：

# test_simple.yaml
ok:
    sub1: sub1

hello:
    world: world
    some: other

如果你安装了 PyYAML 或者一个兼容的yaml解析器，您现在可以执行测试规范：

nonpython $ pytest test_simple.yaml
=========================== test session starts ============================
platform linux -- Python 3.x.y, pytest-6.x.y, py-1.x.y, pluggy-0.x.y
cachedir: $PYTHON_PREFIX/.pytest_cache
rootdir: $REGENDOC_TMPDIR/nonpython
collected 2 items

test_simple.yaml F.                                                  [100%]

================================= FAILURES =================================
______________________________ usecase: hello ______________________________
usecase execution failed
   spec failed: 'some': 'other'
   no further details known at this point.
========================= short test summary info ==========================
FAILED test_simple.yaml::hello
======================= 1 failed, 1 passed in 0.12s ========================

你传球得一分 sub1: sub1 检查一次失败。显然在上面 conftest.py 您将希望实现对yaml值更有趣的解释。您可以用这种方式轻松地编写自己的特定于域的测试语言。

注解

repr_failure(excinfo) 调用以表示测试失败。如果创建自定义集合节点，则可以返回所选的错误表示字符串。它将被报告为（红色）字符串。

reportinfo() 用于表示测试位置，在 verbose 模式：

nonpython $ pytest -v
=========================== test session starts ============================
platform linux -- Python 3.x.y, pytest-6.x.y, py-1.x.y, pluggy-0.x.y -- $PYTHON_PREFIX/bin/python
cachedir: $PYTHON_PREFIX/.pytest_cache
rootdir: $REGENDOC_TMPDIR/nonpython
collecting ... collected 2 items

test_simple.yaml::hello FAILED                                       [ 50%]
test_simple.yaml::ok PASSED                                          [100%]

================================= FAILURES =================================
______________________________ usecase: hello ______________________________
usecase execution failed
   spec failed: 'some': 'other'
   no further details known at this point.
========================= short test summary info ==========================
FAILED test_simple.yaml::hello
======================= 1 failed, 1 passed in 0.12s ========================

在开发自定义测试集合和执行时，只需查看集合树也很有趣：

nonpython $ pytest --collect-only
=========================== test session starts ============================
platform linux -- Python 3.x.y, pytest-6.x.y, py-1.x.y, pluggy-0.x.y
cachedir: $PYTHON_PREFIX/.pytest_cache
rootdir: $REGENDOC_TMPDIR/nonpython
collected 2 items

<Package nonpython>
  <YamlFile test_simple.yaml>
    <YamlItem hello>
    <YamlItem ok>

======================== 2 tests collected in 0.12s ========================