HttpCallbackFunction typings don't work

[cnunciato]

On a new gcp-typescript project (or even a new typescript project with @pulumi/gcp added afterward), the HttpCallbackFunction resource doesn't compile -- at least not when it references req.body or res.send():

import * as pulumi from "@pulumi/pulumi";
import * as gcp from "@pulumi/gcp";

new gcp.cloudfunctions.HttpCallbackFunction("callback", (req, res) => {
    res.send("Hi, world!");
});

The typings suggest this should work, however:

Noticed this while investigating https://github.com/pulumi/examples/issues/1294. Changing the typing of req and res in these examples to :any both compiles and works as expected when deployed, so perhaps the wrong typing is getting picked up somehow during function serialization? Not sure where the error is, but there does seem to be something going wrong somehow.

[viveklak]

Do you have a sense of when this started to break? The typing here hasn't changed in 2 years. The callback is expected to be of this type: https://github.com/pulumi/pulumi-gcp/blame/master/sdk/nodejs/cloudfunctions/zMixins.ts#L415

[cnunciato]

I do not. Only that it was reported recently.