一个单元如何测试用flask编写的REST API端点,该端点接受请求主体的嵌套字典对象?
这是一个使用flask和webargs进行输入验证的示例,
from flask import Flask
from webargs import fields
from webargs.flaskparser import use_args
app = Flask(__name__)
hello_args = {
'a': fields.Nested({'name' : fields.Str()})
}
@app.route('/', methods=['POST'])
@use_args(hello_args)
def index(args):
return 'Hello ' + str(args)
def test_app():
app.config['TESTING'] = True
test_app = app.test_client(use_cookies=False)
test_app.post(data={"a": {"name": "Alice"}})
if __name__ == '__main__':
app.run()
直接使用此enpoint时可以正常工作,
% curl -H "Content-Type: application/json" -X POST \
-d '{"a":{"name": "Alice"}}' http://localhost:5000
Hello {'a': {'name': 'Alice'}}%
但是在单元测试内部调用
werkzeug.test.EnvironBuilder
时会引发异常,nosetests /tmp/test.py
E
======================================================================
ERROR: test.test_app
----------------------------------------------------------------------
Traceback (most recent call last):
File "/usr/lib64/python3.4/site-packages/nose/case.py", line 198, in runTest
self.test(*self.arg)
File "/tmp/test.py", line 26, in test_app
test_app.post(data={"a": {"name": "Alice"}})
File "/home/rth/.local/lib64/python3.4/site-packages/werkzeug/test.py", line 788, in post
return self.open(*args, **kw)
File "/home/rth/.local/lib64/python3.4/site-packages/flask/testing.py", line 103, in open
builder = make_test_environ_builder(self.application, *args, **kwargs)
File "/home/rth/.local/lib64/python3.4/site-packages/flask/testing.py", line 34, in make_test_environ_builder
return EnvironBuilder(path, base_url, *args, **kwargs)
File "/home/rth/.local/lib64/python3.4/site-packages/werkzeug/test.py", line 338, in __init__
self._add_file_from_data(key, value)
File "/home/rth/.local/lib64/python3.4/site-packages/werkzeug/test.py", line 355, in _add_file_from_data
self.files.add_file(key, **value)
TypeError: add_file() got multiple values for argument 'name'
----------------------------------------------------------------------
Ran 1 test in 0.011s
FAILED (errors=1)
它使用Python 3.5,flask 0.12和webargs 1.5.2。
还通过https://github.com/pallets/flask/issues/2176提交了问题
最佳答案
看来,尽管使用了webargs,输入数据仍必须进行序列化并显式指定content_type,这样才能起作用。特别是替换
test_app.post(data={"a": {"name": "Alice"}})
与
test_app.post(data=json.dumps({"a": {"name": "Alice"}}),
content_type='application/json')
解决了此问题(另请参见相关的SO解答here)。