Cannot find name XMLHttpRequest in polling-xhr.d.ts

[Granjow]

With version 4.8.1 of socket.io-client and Node.js 22, "@types/node": "22.13.5" and "typescript": "^5.7.3", I have a build error:

node_modules/engine.io-client/build/esm/transports/polling-xhr.d.ts:65:58 - error TS2304: Cannot find name 'XMLHttpRequest'.

65     constructor(createRequest: (opts: RequestOptions) => XMLHttpRequest, uri: string, opts: RequestOptions);

Probably related: socketio/socket.io-client#1561

[darrachequesne]

Hi! I wasn't able to reproduce: https://github.com/socketio/socket.io/tree/main/examples/typescript-example/esm

$ node -v
v22.8.0

$ npm ls typescript
[email protected] /git/socket.io/socket.io/examples/typescript-example/esm
├─┬ [email protected]
│ └── [email protected] deduped
└── [email protected]

$ npm ls @types/node
[email protected] /git/socket.io/socket.io/examples/typescript-example/esm
├─┬ [email protected]
│ └─┬ [email protected]
│   ├─┬ @types/[email protected]
│   │ └── @types/[email protected] deduped
│   └── @types/[email protected] deduped
└─┬ [email protected]
  └── @types/[email protected]

$ npm run build

> [email protected] build
> tsc

Could you please check?

[jokester]

XMLHttpRequest is not provided by this library. It is meant to be provided by tsc.

@Granjow Did you have lib: ["dom"] or equalivient in tsconfig.json ?

[Granjow]

@jokester I have these compiler options:

  "compilerOptions": {
    "composite": true,
    "outDir": "dist",
    "module": "commonjs",
    "noImplicitAny": true,
    "removeComments": false,
    "preserveConstEnums": true,
    "inlineSourceMap": true,
    "declaration": true,
    "moduleResolution": "node",
    "esModuleInterop": true,
    "target": "es6",
    "strict": true,
    "jsx": "preserve",
    "lib": [
      "es2018",
      "esnext"
    ]
  }

[perry-mitchell]

Have the same issue:

• node 23
• typescript 5.8

tsconfig:

{
  "$schema": "https://json.schemastore.org/tsconfig",
  "compilerOptions": {
    "strict": true,
    "strictNullChecks": true,
    "skipLibCheck": false,
    "esModuleInterop": true,
    "resolveJsonModule": true,
    "allowSyntheticDefaultImports": true,
    "noImplicitAny": true,
    "forceConsistentCasingInFileNames": true,
    "target": "es2022",
    "module": "ESNext",
    "moduleResolution": "Bundler",
    "declaration": true,
    "lib": ["es2022"],
    "outDir": "dist",
    "types": ["node"]
  },
  "include": ["source/**/*"],
  "exclude": ["node_modules", "dist"]
}

../../node_modules/engine.io-client/build/esm/transports/polling-xhr.d.ts:65:58 - error TS2304: Cannot find name 'XMLHttpRequest'.

65     constructor(createRequest: (opts: RequestOptions) => XMLHttpRequest, uri: string, opts: RequestOptions);
                                                            ~~~~~~~~~~~~~~


Found 1 error in ../../node_modules/engine.io-client/build/esm/transports/polling-xhr.d.ts:65

It seems that socket.io-client doesn't want to run on base Node/TS. It's a typescript bug in this library.

Did you have lib: ["dom"] or equalivient in tsconfig.json ?

DOM fixes the issue, however it should not be required for a library that is compatible with NodeJS. XMLHttpRequest is not relevant for Node and developers shouldn't be expected to add the DOM types to get this to work, in my opinion.

[jokester]

@perry-mitchell That's totally reasonable.

I may have a fix. Can any of you try adding this to local polling-xhr.d.ts (under node_modules, cjs or esm depends on your usage), ensure tsconfig doesn't have lib: ['dom'] , and see if the type error persists?

/**
 * A dummy interface to satisfy TypeScript's type checking.
 * When real XHR is avaiable, this do nothing.
 * Otherwise this is a placeholder type to silent tsc.
 */
interface XMLHttpRequest { }

[perry-mitchell]

Hi @jokester - thanks for the quick response.

I've already switched to using Rollup to bundle the backend of this particular project - it handles the needs of socket.io-client just fine, it seems. I'm not sure what it does under the hood - it may well provide a XHR-compatible client which squelches the error. So for now I'll probably just stick with this, thanks.