Playwright tests broken on Node.js ≥23.6.0 due to type stripping feature

[praseodym]

Node.js 23.6.0 enables the type stripping feature by default. This breaks our Playwright tests:

$ npm run e2e:d2d -- --project chrome

> [email protected] e2e:d2d
> cross-env LOCAL_CI=true playwright test -c playwright.d2d.config.ts --project chrome

(node:18607) ExperimentalWarning: Type Stripping is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)

[..]

SyntaxError:   x TypeScript enum is not supported in strip-only mode
   ,-[1:1]
 1 | ,-> export enum ApiResponseStatus {
 2 | |     Success,
 3 | |     ClientError,
 4 | |     ServerError,
 5 | `-> }
   `----

SyntaxError:   x TypeScript parameter property is not supported in strip-only mode
    ,-[8:1]
  5 | 
  6 |   readonly downloadZip: Locator;
  7 | 
  8 |   constructor(protected readonly page: Page) {
    :                                  ^^^^^^^^^^
  9 |     this.downloadPdf = page.getByRole("button", { name: "Download los proces-verbaal" });
 10 |     this.downloadZip = page.getByRole("button", { name: "Download proces-verbaal met telbestand" });
 11 |   }
    `----

[..]

We are currently requiring Node.js 22 (LTS) and don't support Node.js 23 officially, but it might be an issue that we have to resolve at some point in the future.

[jschuurk-kr]

Playwright issue says its not their problem and recommends using --experimental-transform-types as mentioned in the Node.js docs linked in the description of this issue.

Tangentially, the Playwright docs say about TypeScript: "Note that Playwright does not check the types and will run tests even if there are non-critical TypeScript compilation errors. We recommend you run TypeScript compiler alongside Playwright."

[praseodym]

I found that issue too, but find it strange that Node.js is now suddenly running code with TypeScript types included. I'd expected the TypeScript types to be stripped out before running regardless of the Node.js version.

[MarkusJLechner]

Edit: will post that to playwright issue.

I ran into the same problem. After removing all enums, Playwright completely breaks with a SyntaxError: Invalid or unexpected token error. The issue occurs when using npx playwright or pnpm exec playwright. Inside node_modules/.bin/playwright, the command is defined as:

node "$basedir/../playwright/cli.js" "$@"

For Node.js 23+, this needs to be changed to:

node --no-experimental-strip-types "$basedir/../playwright/cli.js" "$@"

Without this change, the tests won’t start. Since Playwright has its own mechanism for running TypeScript files, Node.js interferes with its type-stripping feature.

Reference: Node.js TypeScript API
See also: Full TypeScript Support

Temporary Solution

Until this is fixed, in package.json I use:

"scripts": {
  "test": "node --no-experimental-strip-types node_modules/playwright/cli.js test"
}

Error

(node:567908) ExperimentalWarning: Type Stripping is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
SyntaxError: Invalid or unexpected token
    at compileSourceTextModule (node:internal/modules/esm/utils:338:16)
    at ModuleLoader.moduleStrategy (node:internal/modules/esm/translators:106:18)
    at ModuleLoader.<anonymous> (node:internal/modules/esm/translators:549:10)
    at ModuleLoader.#translate (node:internal/modules/esm/loader:470:12)
    at ModuleLoader.loadAndTranslate (node:internal/modules/esm/loader:517:27)