regression in "Build failed with error TS2416 in firebase-functions"

[NathanC]

I'm filing this because there's been a serious regression on an old issue and there's a lot of discussion/new comments that aren't being responded to, I believe due to the issue being closed. Can we get some eyes on it?

Issue that's regressed: #1442

[google-oss-bot]

I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.

[xsorifc28]

👀

[sebastianrueckerai]

I am having the same issue when compiling my TS code to JS with these packages installed:

    "firebase-admin": "^12.0.0",
    "firebase-functions": "^4.6.0",

Output:

$ npm run clean && tsc

node_modules/firebase-functions/lib/common/providers/database.d.ts:80:5 - error TS2416: Property 'child' in type 'DataSnapshot' is not assignable to the same property in base type 'DataSnapshot'.
  Type '(childPath: string) => DataSnapshot' is not assignable to type '(path: string) => DataSnapshot'.
    Call signature return types 'DataSnapshot' and 'DataSnapshot' are incompatible.
      The types of 'forEach' are incompatible between these types.
        Type '(action: (a: DataSnapshot) => boolean | void) => boolean' is not assignable to type '(action: (a: IteratedDataSnapshot) => boolean | void) => boolean'.
          Types of parameters 'action' and 'action' are incompatible.
            Types of parameters 'a' and 'a' are incompatible.
              Type 'DataSnapshot' is not assignable to type 'IteratedDataSnapshot'.
                Types of property 'key' are incompatible.
                  Type 'string | null' is not assignable to type 'string'.
                    Type 'null' is not assignable to type 'string'.

[baraknaveh]

I have the exact same issue.

I am having the same issue when compiling my TS code to JS with these packages installed:

    "firebase-admin": "^12.0.0",
    "firebase-functions": "^4.6.0",

Output:

$ npm run clean && tsc

node_modules/firebase-functions/lib/common/providers/database.d.ts:80:5 - error TS2416: Property 'child' in type 'DataSnapshot' is not assignable to the same property in base type 'DataSnapshot'.
  Type '(childPath: string) => DataSnapshot' is not assignable to type '(path: string) => DataSnapshot'.
    Call signature return types 'DataSnapshot' and 'DataSnapshot' are incompatible.
      The types of 'forEach' are incompatible between these types.
        Type '(action: (a: DataSnapshot) => boolean | void) => boolean' is not assignable to type '(action: (a: IteratedDataSnapshot) => boolean | void) => boolean'.
          Types of parameters 'action' and 'action' are incompatible.
            Types of parameters 'a' and 'a' are incompatible.
              Type 'DataSnapshot' is not assignable to type 'IteratedDataSnapshot'.
                Types of property 'key' are incompatible.
                  Type 'string | null' is not assignable to type 'string'.
                    Type 'null' is not assignable to type 'string'.

[sceee]

Duplicates #1513

[vandres]

As a temporary workaround, I've set "skipLibCheck": true in tsconfig.json

[mariopepe]

I am getting this error right now with:

  "dependencies": {
    "@faker-js/faker": "^8.4.0",
    "@types/google-libphonenumber": "^7.4.30",
    "@types/nodemailer": "^6.4.14",
    "axios": "^1.6.7",
    "firebase-admin": "^12.0.0",
    "firebase-functions": "^4.6.0",
    "fp-ts": "^2.16.2",
    "google-libphonenumber": "^3.2.34",
    "meilisearch": "^0.37.0",
    "nodemailer": "^6.9.8",
    "urlcat": "^3.1.0",
    "uuid": "^9.0.1"
  },

The error I get is:

npm run build

> build
> tsc

node_modules/firebase-functions/lib/common/providers/database.d.ts:80:5 - error TS2416: Property 'child' in type 'DataSnapshot' is not assignable to the same property in base type 'DataSnapshot'.
  Type '(childPath: string) => DataSnapshot' is not assignable to type '(path: string) => DataSnapshot'.
    Call signature return types 'DataSnapshot' and 'DataSnapshot' are incompatible.
      The types of 'forEach' are incompatible between these types.
        Type '(action: (a: DataSnapshot) => boolean | void) => boolean' is not assignable to type '(action: (a: IteratedDataSnapshot) => boolean | void) => boolean'.
          Types of parameters 'action' and 'action' are incompatible.
            Types of parameters 'a' and 'a' are incompatible.
              Type 'DataSnapshot' is not assignable to type 'IteratedDataSnapshot'.
                Types of property 'key' are incompatible.
                  Type 'string | null' is not assignable to type 'string'.
                    Type 'null' is not assignable to type 'string'.

80     child(childPath: string): DataSnapshot;
       ~~~~~

node_modules/firebase-functions/lib/common/providers/database.d.ts:100:5 - error TS2416: Property 'forEach' in type 'DataSnapshot' is not assignable to the same property in base type 'DataSnapshot'.
  Type '(action: (a: DataSnapshot) => boolean | void) => boolean' is not assignable to type '(action: (a: IteratedDataSnapshot) => boolean | void) => boolean'.

100     forEach(action: (a: DataSnapshot) => boolean | void): boolean;
        ~~~~~~~


Found 2 errors in the same file, starting at: node_modules/firebase-functions/lib/common/providers/database.d.ts:80