TypeScript: @types/express version ambiguity breaks build

[montasaurus]

Related issues

#610

[REQUIRED] Version info

node: v13.12.0

firebase-functions: 3.6.1

firebase-tools: 8.2.0

firebase-admin: ^8.11.0

[REQUIRED] Test case

import * as functions from "firebase-functions";
functions.https.onCall((data, context) => {}); // error TS2707: Generic type 'Request<P>' requires between 0 and 1 type arguments.

[REQUIRED] Steps to reproduce

Upgrade the firebase-functions package to 3.6.1 with @types/express already installed and resolved to version 4.17.3 (which matches the spec for this package). Run tsc and watch the build fail.

[REQUIRED] Expected behavior

The build should succeed.

[REQUIRED] Actual behavior

The build fails because the type signatures have changed in @types/express since the spec version in package.json. Breaking change here: DefinitelyTyped/DefinitelyTyped@bb26736

- error TS2707: Generic type 'Request<P>' requires between 0 and 1 type arguments.

64         onCall: (handler: (data: any, context: https.CallableContext) => any) => import("./cloud-functions").TriggerAnnotated & ((req: express.Request<import("express-serve-static-core").ParamsDictionary, any, any, import("express-serve-static-core").Query>, resp: express.Response<any>) => void) & import("./cloud-functions").Runnable<any>;
                                                                                                                                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

node_modules/firebase-functions/lib/function-builder.d.ts:64:252 - error TS2694: Namespace '"/Users/adam/code/functions/node_modules/@types/express-serve-static-core/index"' has no exported member 'Query'.

64         onCall: (handler: (data: any, context: https.CallableContext) => any) => import("./cloud-functions").TriggerAnnotated & ((req: express.Request<import("express-serve-static-core").ParamsDictionary, any, any, import("express-serve-static-core").Query>, resp: express.Response<any>) => void) & import("./cloud-functions").Runnable<any>;
                                                                                                                                                                                                                                                              ~~~~~

The DefinitelyTyped bindings don't usually respect SemVer, so they should probably be pinned to a specific version in package.json or locked with package-lock.json.

Were you able to successfully deploy your functions?

No

[laurenzlong]

This has now been fixed in 3.6.2

[LFDM]

In case someone else stumbles across this:
The fix above only partially fixes the issues with the express types. The culprit lies deeper: @types/express-serve-static-core doesn't have a fixed version within @types/express either, so it can lag behind on your system - this is what happened for me.

For now I just manually added the latest version of @types/express-serve-static-core to my own package.json (4.17.8), which works fine.
At the end of the day this needs to be fixed in @types/express.

---

Update: The above was a red herring. Fixed some issues, but also created others. The search continues.

---

Update 2:
I had to remove all older versions of @types/express-serve-static-core that were hanging out in my yarn.lock - otherwise some packages, such as firebase-functions, would refuse to use a newer version.
After I had this removed, calling yarn again (I suppose the same would apply for npm) made everyone use the newest types and I am finally able to build again.