typescript tsc build failed with error about module "strict-event-emitter" has no exported member 'StrictEventEmitter'.

[neekey]

Prerequisites

• I confirm my issue is not in the opened issues
• I confirm the Frequently Asked Questions didn't contain the answer to my issue

Environment check

• I'm using the latest msw version
• I'm using Node.js version 14 or higher

Node.js version

v16.15.0

Reproduction repository

https://codesandbox.io/p/sandbox/confident-hugle-fz9j6l

Reproduction steps

The current setup is super simple:

• it has msw@1.2.3 installed
• it has typescript@4.5.4 installed

it has a dummy index.ts file which imported msw:

import { rest } from "msw";
import { setupServer } from "msw/node";

setupServer(
  // Handles a POST /login request
  rest.post("/hello_world", (req, res, ctx) => {
    return res(
      ctx.status(200),
      ctx.json({
        success: true,
      })
    );
  })
);

To reproduce the issue:

open the sandbox repo, simply in the terminal run: npm run build
you will see error while tsc trying to build the src/index.ts.

Current behavior

Got error:

node_modules/@mswjs/interceptors/lib/BatchInterceptor.d.ts:1:10 - error TS2724: '"strict-event-emitter"' has no exported member named 'EventMapType'. Did you mean 'EventMap'?

1 import { EventMapType } from 'strict-event-emitter';
           ~~~~~~~~~~~~

node_modules/@mswjs/interceptors/lib/utils/AsyncEventEmitter.d.ts:1:10 - error TS2305: Module '"strict-event-emitter"' has no exported member 'StrictEventEmitter'.

1 import { StrictEventEmitter, EventMapType } from 'strict-event-emitter';
           ~~~~~~~~~~~~~~~~~~

node_modules/@mswjs/interceptors/lib/utils/AsyncEventEmitter.d.ts:1:30 - error TS2724: '"strict-event-emitter"' has no exported member named 'EventMapType'. Did you mean 'EventMap'?

1 import { StrictEventEmitter, EventMapType } from 'strict-event-emitter';
                               ~~~~~~~~~~~~


Found 3 errors in 2 files.

Expected behavior

The build should finish without error

[kettanaito]

Hi, @neekey. Thanks for reporting this.

This issue is caused by the different versions of strict-event-emitter that get installed:

└─┬ msw@1.2.3
  ├─┬ @mswjs/interceptors@0.17.9
  │ └── strict-event-emitter@0.2.8
  └── strict-event-emitter@0.4.6

I've started the effort to publish a backport to @mswjs/interceptors that'd bump that dependency to 0.4 in mswjs/interceptors#382 but encountered some type conflicts and didn't move further with that.

How to solve this?

To resolve this, disable type-checking of third-party libraries by setting "skipLibCheck": true in yout tsconfig.json. You shouldn't be validating third-party types anyway, and it's a good default to have that option enabled in your projects.

I will close this issue because it's not something we can address on MSW's side.