Mocking up an Azure Functions httpRequest form in Python

Question

I'm writing tests for an Azure Function. The function reads multipart/form-data from the frontend, which it accesses using data = dict(req.form) where req is the func.HttpRequest. This works fine, and I can access the form data passed from the frontend. My problem is I can't seem to mock up the req.form object for my unit tests. I've written:

    req = func.HttpRequest(
        method="POST",
        headers={
            "x-ms-client-principal": my-test-user-object,
            "Content-Type": "multipart/form-data"
        },
        body=SOMETHING-GOES-HERE,
        url="/api/users"
    )

I've tried setting the body to a bytes object; this allows me to access the bytes object using req.get_body(). When I dump a JSON object I can get it with req.get_json(). But I can't figure out what to pass in so that I can access it using req.form. Does anyone know how to do this?

Answer 1

I ended up finding the solution on this blog post. The encode_multipart_formdata() function described in the blog post allows for the creation of a mock form which can then be passed into the body of the HttpResponse object as follows:

body, content_type = encode_multipart_formdata({
    "username": os.environ["TEST_USERNAME1"],
    "email": os.environ["TEST_USER_EMAIL2"]
})
req = func.HttpRequest(
    method="POST",
    headers={
        "x-ms-client-principal": my-test-user-obj,
        "Content-Type": content_type
    },
    body=bytes(body, "utf-8"),
    url="/api/users"
)

Answer 2

We can use the function in a below way to get the whole form in return response

def main(req: func.HttpRequest) -> func.HttpResponse:
    logging.info('Python HTTP trigger function processed a request.')
    return func.HttpResponse(
        json.dumps({
            'method': req.method,
            'url': req.url,
            'headers': dict(req.headers),
            'params': dict(req.params),
            'get_body': req.get_body().decode()
        })
    )

Or below example will make us to understand more about request.form to check the form data.