This was so because we pass paramOverride to useKeyserverCall that looks like this:

const serverCallParamOverride = React.useMemo(
  () => ({
    keyserverInfos: {
      [(keyserverURL: string)]: {
        urlPrefix: keyserverURL,
      },
    },
  }),
  [keyserverURL],
);

So the keyserverInfos are not of type KeyserverInfos, because they are missing some fields.
We spread paramOverride into bindCallKeyserverEndpointToAction, and override the keyserverInfos field. So it does take partial KeyserverInfos sometimes. I think this is just to complicated for flow to catch.

Currently we always expect urlPrefix to be provided, but connectionStatus can probably fallback to default. Although I think this would require checking if getVersion still works, because I can see that in callServerEndpoint if connectionStatus === 'connected' we use the socket, and otherwise we use the fetch, so we would stat using the socket I think? I remember @ginsu having a similar issue, but I can't find the discussion

Thanks @inka!

I think this is just to complicated for flow to catch.

I looked into why Flow is unable to correctly typecheck the code snippet in your last comment, which should have printed a type error in my initial revision of this diff. It looks like the computed property there is confusing Flow: replacing that with a normal property correctly flagged the type error.

Currently we always expect urlPrefix to be provided

I updated the diff to require that KeyserverInfoPartial always specifies urlPrefix.

connectionStatus can probably fallback to default. Although I think this would require checking if getVersion still works, because I can see that in callServerEndpoint if connectionStatus === 'connected' we use the socket, and otherwise we use the fetch, so we would stat using the socket I think? I remember @ginsu having a similar issue, but I can't find the discussion

To avoid using the socket, I opted to default to disconnected when no connectionStatus is specified.