Spec incorrectly states that lang field in response to /pushers is required

[nico-famedly]

Link to problem area:

matrix-spec/data/api/client-server/pusher.yaml

Line 103 in 99e2ff4

- lang

Issue

Synapse seems to not set that field, which seems to cause problems in SDKs generated from the openapi spec:

https://github.com/matrix-org/synapse/blob/3de82bb2af28f56696a79bf41ccffc81385b6e2c/synapse/rest/admin/users.py#L470

https://github.com/matrix-org/synapse/blob/3de82bb2af28f56696a79bf41ccffc81385b6e2c/synapse/handlers/register.py#L1022

famedly/dart_matrix_api_lite#136

[richvdh]

Please do link to the relevant part of the spec when reporting issues - it makes it way easier to understand the context.

This is about https://spec.matrix.org/v1.9/client-server-api/#get_matrixclientv3pushers, I believe.

If synapse has been omitting this since 2015 we can probably just update the spec to match, though it would be good to get evidence of that.

[Johennes]

If synapse has been omitting this since 2015 we can probably just update the spec to match, though it would be good to get evidence of that.

It seems like the lang field on pushers in Synapse was introduced in 2015 and has been nullable from the start. The email pusher that is set up for 3PID registrations with lang=None was added in 2016.

[Johennes]

Tagging on to that, when creating a pusher via the API, Synapse does enforce the presence of lang.

So any pusher created directly by a client will always have the lang field but some of the pushers that Synapse creates autonomously don't.

[Johennes]

Maybe rather than making lang optional in GET /pushers we should try to make lang available in the places where Synapse currently sets None? I haven't actually checked these places but I suppose that would require adding lang to further APIs.