在HttpRunner3的示例代码中，发送HTTP请求的代码是这样写的：
from httprunner import HttpRunner, Config, Step, RunRequest, RunTestCase
class TestCaseBasic(HttpRunner):
config = Config("basic test with httpbin").base_url("https://httpbin.org/")
teststeps = [
Step(
RunRequest("headers")
.get("/headers")
.validate()
.assert_equal("status_code", 200)
.assert_equal("body.headers.Host", "httpbin.org")
),
# 省略
Step(
RunRequest("post data")
.post("/post")
.with_headers(**{"Content-Type": "application/json"})
.with_data("abc")
.validate()
.assert_equal("status_code", 200)
),
# 省略
]
if __name__ == "__main__":
TestCaseBasic().test_start()
- 类TestCaseBasic继承了类HttpRunner。
- 在类TestCaseBasic的内部定义了teststeps列表，由多个Step类的实例对象组成。
- 类Step初始化传入类RunRequest的方法get和post就把HTTP请求发出去了。
这到底是怎么实现的？
先看下RunRequest的源码：
class RunRequest(object):
def __init__(self, name: Text):
self.__step_context = TStep(name=name)
def with_variables(self, **variables) -> "RunRequest":
self.__step_context.variables.update(variables)
return self
def setup_hook(self, hook: Text, assign_var_name: Text = None) -> "RunRequest":
if assign_var_name:
self.__step_context.setup_hooks.append({assign_var_name: hook})
else:
self.__step_context.setup_hooks.append(hook)
return self
def get(self, url: Text) -> RequestWithOptionalArgs:
self.__step_context.request = TRequest(method=MethodEnum.GET, url=url)
return RequestWithOptionalArgs(self.__step_context)
def post(self, url: Text) -> RequestWithOptionalArgs:
self.__step_context.request = TRequest(method=MethodEnum.POST, url=url)
return RequestWithOptionalArgs(self.__step_context)
def put(self, url: Text) -> RequestWithOptionalArgs:
self.__step_context.request = TRequest(method=MethodEnum.PUT, url=url)
return RequestWithOptionalArgs(self.__step_context)
def head(self, url: Text) -> RequestWithOptionalArgs:
self.__step_context.request = TRequest(method=MethodEnum.HEAD, url=url)
return RequestWithOptionalArgs(self.__step_context)
def delete(self, url: Text) -> RequestWithOptionalArgs:
self.__step_context.request = TRequest(method=MethodEnum.DELETE, url=url)
return RequestWithOptionalArgs(self.__step_context)
def options(self, url: Text) -> RequestWithOptionalArgs:
self.__step_context.request = TRequest(method=MethodEnum.OPTIONS, url=url)
return RequestWithOptionalArgs(self.__step_context)
def patch(self, url: Text) -> RequestWithOptionalArgs:
self.__step_context.request = TRequest(method=MethodEnum.PATCH, url=url)
return RequestWithOptionalArgs(self.__step_context)
里面定义了get、post等HTTP请求的Method。方法内部：
self.__step_context.request = TRequest(method=MethodEnum.GET, url=url)
有个TRequest类：
class TRequest(BaseModel):
"""requests.Request model"""
method: MethodEnum
url: Url
params: Dict[Text, Text] = {}
headers: Headers = {}
req_json: Union[Dict, List, Text] = Field(None, alias="json")
data: Union[Text, Dict[Text, Any]] = None
cookies: Cookies = {}
timeout: float = 120
allow_redirects: bool = True
verify: Verify = False
upload: Dict = {} # used for upload files
它继承了pydantic.BaseModel，是用来做数据验证的，比如这里的url指定了Url类型，如果传一个str类型，就会校验失败。简而言之，这是给代码规范用的，没有实际的业务功能。
下面有一行注释：requests.Request mode，看来这个跟requests有点关系。
回过头来看看self.__step_context.request，也就是self.__step_context对象有个request属性，它的定义是：
self.__step_context = TStep(name=name)
答案应该就在TStep中了：
class TStep(BaseModel):
name: Name
request: Union[TRequest, None] = None
testcase: Union[Text, Callable, None] = None
variables: VariablesMapping = {}
setup_hooks: Hooks = []
teardown_hooks: Hooks = []
# used to extract request's response field
extract: VariablesMapping = {}
# used to export session variables from referenced testcase
export: Export = []
validators: Validators = Field([], alias="validate")
validate_script: List[Text] = []
还是个Model，里面的request定义是：
request: Union[TRequest, None] = None
又绕回TRequest了。这个Union是typing模块里面的：Union[X, Y] means either X or Y. 意思就是request的类型要么是TRequest要么是None。
在刚才get的方法中，还有一句return RequestWithOptionalArgs(self.__step_context)，RequestWithOptionalArgs的定义如下：
class RequestWithOptionalArgs(object):
def __init__(self, step_context: TStep):
self.__step_context = step_context
def with_params(self, **params) -> "RequestWithOptionalArgs":
self.__step_context.request.params.update(params)
return self
def with_headers(self, **headers) -> "RequestWithOptionalArgs":
self.__step_context.request.headers.update(headers)
return self
def with_cookies(self, **cookies) -> "RequestWithOptionalArgs":
self.__step_context.request.cookies.update(cookies)
return self
def with_data(self, data) -> "RequestWithOptionalArgs":
self.__step_context.request.data = data
return self
def with_json(self, req_json) -> "RequestWithOptionalArgs":
self.__step_context.request.req_json = req_json
return self
def set_timeout(self, timeout: float) -> "RequestWithOptionalArgs":
self.__step_context.request.timeout = timeout
return self
def set_verify(self, verify: bool) -> "RequestWithOptionalArgs":
self.__step_context.request.verify = verify
return self
def set_allow_redirects(self, allow_redirects: bool) -> "RequestWithOptionalArgs":
self.__step_context.request.allow_redirects = allow_redirects
return self
def upload(self, **file_info) -> "RequestWithOptionalArgs":
self.__step_context.request.upload.update(file_info)
return self
def teardown_hook(
self, hook: Text, assign_var_name: Text = None
) -> "RequestWithOptionalArgs":
if assign_var_name:
self.__step_context.teardown_hooks.append({assign_var_name: hook})
else:
self.__step_context.teardown_hooks.append(hook)
return self
def extract(self) -> StepRequestExtraction:
return StepRequestExtraction(self.__step_context)
def validate(self) -> StepRequestValidation:
return StepRequestValidation(self.__step_context)
def perform(self) -> TStep:
return self.__step_context
可以给HTTP请求添加params、headers等可选项。
看到这里，仍然不知道HTTP请求到底发出去的，因为没有调用呀。
只能往上层找，看调用RunRequest的Step类：
class Step(object):
def __init__(
self,
step_context: Union[
StepRequestValidation,
StepRequestExtraction,
RequestWithOptionalArgs,
RunTestCase,
StepRefCase,
],
):
self.__step_context = step_context.perform()
@property
def request(self) -> TRequest:
return self.__step_context.request
@property
def testcase(self) -> TestCase:
return self.__step_context.testcase
def perform(self) -> TStep:
return self.__step_context
Step类的__init__方法也用Union做了类型校验，其中RequestWithOptionalArgs就是RunRequest的gei等方法会返回的，这倒是匹配上了。它还有个request属性。有点眉目了。
再往上层找，看HttpRunner类，有个__run_step_request的方法：
def __run_step_request(self, step: TStep) -> StepData:
"""run teststep: request"""
step_data = StepData(name=step.name)
# parse
prepare_upload_step(step, self.__project_meta.functions)
request_dict = step.request.dict()
request_dict.pop("upload", None)
parsed_request_dict = parse_data(
request_dict, step.variables, self.__project_meta.functions
)
parsed_request_dict["headers"].setdefault(
"HRUN-Request-ID",
f"HRUN-{self.__case_id}-{str(int(time.time() * 1000))[-6:]}",
)
step.variables["request"] = parsed_request_dict
# setup hooks
if step.setup_hooks:
self.__call_hooks(step.setup_hooks, step.variables, "setup request")
# prepare arguments
method = parsed_request_dict.pop("method")
url_path = parsed_request_dict.pop("url")
url = build_url(self.__config.base_url, url_path)
parsed_request_dict["verify"] = self.__config.verify
parsed_request_dict["json"] = parsed_request_dict.pop("req_json", {})
# request
resp = self.__session.request(method, url, **parsed_request_dict)
resp_obj = ResponseObject(resp)
step.variables["response"] = resp_obj
# teardown hooks
if step.teardown_hooks:
self.__call_hooks(step.teardown_hooks, step.variables, "teardown request")
def log_req_resp_details():
err_msg = "\n{} DETAILED REQUEST & RESPONSE {}\n".format("*" * 32, "*" * 32)
# log request
err_msg += "====== request details ======\n"
err_msg += f"url: {url}\n"
err_msg += f"method: {method}\n"
headers = parsed_request_dict.pop("headers", {})
err_msg += f"headers: {headers}\n"
for k, v in parsed_request_dict.items():
v = utils.omit_long_data(v)
err_msg += f"{k}: {repr(v)}\n"
err_msg += "\n"
# log response
err_msg += "====== response details ======\n"
err_msg += f"status_code: {resp.status_code}\n"
err_msg += f"headers: {resp.headers}\n"
err_msg += f"body: {repr(resp.text)}\n"
logger.error(err_msg)
# extract
extractors = step.extract
extract_mapping = resp_obj.extract(extractors)
step_data.export_vars = extract_mapping
variables_mapping = step.variables
variables_mapping.update(extract_mapping)
# validate
validators = step.validators
session_success = False
try:
resp_obj.validate(
validators, variables_mapping, self.__project_meta.functions
)
session_success = True
except ValidationFailure:
session_success = False
log_req_resp_details()
# log testcase duration before raise ValidationFailure
self.__duration = time.time() - self.__start_at
raise
finally:
self.success = session_success
step_data.success = session_success
if hasattr(self.__session, "data"):
# httprunner.client.HttpSession, not locust.clients.HttpSession
# save request & response meta data
self.__session.data.success = session_success
self.__session.data.validators = resp_obj.validation_results
# save step data
step_data.data = self.__session.data
return step_data
就是这里了，它的函数名用了双下划线开头：双下划线前缀会让Python解释器重写属性名称，以避免子类中的命名冲突。 这也称为名称改写（name mangling），即解释器会更改变量的名称，以便在稍后扩展这个类时避免命名冲突。说人话就是，类的私有成员，只能在类的内部调用，不对外暴露。它只在__run_step()方法中调用了1次：step_data = self.__run_step_request(step)。
中间有一段：
# request
resp = self.__session.request(method, url, **parsed_request_dict)
resp_obj = ResponseObject(resp)
step.variables["response"] = resp_obj
好家伙，self.__session.request()，跟reqeusts那个有点像了。点进去。
一下就跳转到了httprunner.client.py，众里寻他千百度，默然回首，它竟然就在client。
class HttpSession(requests.Session):
"""
Class for performing HTTP requests and holding (session-) cookies between requests (in order
to be able to log in and out of websites). Each request is logged so that HttpRunner can
display statistics.
This is a slightly extended version of `python-request <http://python-requests.org>`_'s
:py:class:`requests.Session` class and mostly this class works exactly the same.
"""
def __init__(self):
super(HttpSession, self).__init__()
self.data = SessionData()
def update_last_req_resp_record(self, resp_obj):
"""
update request and response info from Response() object.
"""
# TODO: fix
self.data.req_resps.pop()
self.data.req_resps.append(get_req_resp_record(resp_obj))
def request(self, method, url, name=None, **kwargs):
继承了requests.Session然后进行了重写。
果然，还是用到了requests库。
参考资料：
https://github.com/httprunner/httprunner
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