v0.6.5: BrowserContext type mismatch due to inlined playwright-core types in bundled .d.mts

[ysgk]

Description

After upgrading from v0.6.4 to v0.6.5, TypeScript reports a type error when passing @playwright/test's BrowserContext to defineNetworkFixture.

Steps to reproduce

import { test as base } from '@playwright/test'
import { defineNetworkFixture } from '@msw/playwright'

const test = base.extend({
  network: async ({ context }, use) => {
    // TS2322: Type 'BrowserContext' (from @playwright/test) is not assignable
    // to type 'BrowserContext' (inlined in @msw/playwright's bundled types)
    const network = defineNetworkFixture({ context })
    await network.enable()
    await use(network)
    await network.disable()
  },
})

Root cause

The v0.6.5 release (#43) changed the exports conditions. As a result, build/index.d.mts now inlines all of playwright-core's type definitions (~23,000 lines, 1.6MB file).

The source code correctly imports BrowserContext from @playwright/test:

// src/fixture.ts
import type { BrowserContext } from '@playwright/test'

But after bundling with tsdown, this becomes a locally declared BrowserContext interface inside the .d.mts file, rather than a reference to the user's installed @playwright/test types. TypeScript treats these as distinct types, causing the mismatch.

Expected behavior

@playwright/test (or playwright-core) should be marked as external in the tsdown bundle configuration so that the type definition emits an import statement rather than inlining the types.

Environment

• @msw/playwright: 0.6.5
• @playwright/test: 1.58.2
• TypeScript: 5.8.2

[kleinfreund]

Possible fix: turning on tsdown's skipNodeModulesBundle.

In tsdown.config.ts:

  import { defineConfig } from 'tsdown'

  export default defineConfig({
    entry: ['./src/index.ts'],
    format: 'esm',
    outDir: './build',
    clean: true,
    dts: true,
+   deps: {
+     skipNodeModulesBundle: true,
+   },
  })

The resulting dist/index.mjs is identical and the resulting dist/index.d.mts becomes:

import { AnyHandler, LifeCycleEventsMap, SetupApi, UnhandledRequestStrategy } from "msw";
import { BrowserContext } from "@playwright/test";

//#region src/fixture.d.ts
interface NetworkFixtureOptions {
  context: BrowserContext;
  handlers?: Array<AnyHandler>;
  onUnhandledRequest?: UnhandledRequestStrategy;
  /**
   * Skip common asset requests (e.g. `*.html`, `*.css`, `*.js`, etc).
   * This improves performance for certian projects.
   * @default true
   *
   * @see https://mswjs.io/docs/api/is-common-asset-request
   */
  skipAssetRequests?: boolean;
}
type NetworkFixture = Omit<SetupApi<LifeCycleEventsMap>, 'dispose'> & {
  enable: () => Promise<void>;
  disable: () => Promise<void>;
};
declare function defineNetworkFixture(options: NetworkFixtureOptions): NetworkFixture;
//#endregion
export { type NetworkFixture, type NetworkFixtureOptions, defineNetworkFixture };

[kettanaito]

Thanks for reporting this, @ysgk. I've added a type test and fixed the issue by listing @playwright/test in the deps.neverBundle option meant for external dependencies.

[kettanaito]

Released: v0.6.6 🎉

This has been released in v0.6.6.

• 📄 Release notes
• 📦 View on npm

Get these changes by running the following command:

npm i @msw/playwright@latest

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