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Type annotations: I think werkzeug.wrappers.Request.json can never be None #3067
Description
I am talking about this property: https://werkzeug.palletsprojects.com/en/stable/wrappers/#werkzeug.wrappers.Request.json
werkzeug/src/werkzeug/wrappers/request.py
Lines 544 to 545 in 504a8c4
I think it can never actually return None, because it calls get_json() with all defaults, which is silent=False, making it never return None and raise in those cases instead.
This issue is still current in the latest release and latest unreleased code.
I am using Pyright, and it complains about usages such as flask.request.json["foo"].
Reacted by Edgar Ramírez Mondragón
Activity
ThiefMaster commentedon Nov 23, 2025
w/o checking the code: What if the request payload is literally
nullwhich, when parsed as json, becomesNone?oprypin commentedon Nov 23, 2025
@ThiefMaster Uhh yes, that's technically true.
However, the intentions of the type annotations around here are clearly the following:
Anymeans "any JSON type" (without special-casing null)Any | Nonemeans the same, OR that it was not provided.You can see this logic applied in the definitions of
get_json()right below.oprypin commentedon Nov 23, 2025
Or from the pragmatic perspective:
The code
some_json["foo"]has many reasons to fail, and the situation where it's null should get equal treatment to the situation where it's a list instead.Preventing only the
Nonecase is not meaningful when the other case can still be let through.