[Bug]: NodeJS 23.6.0 breaks tests using Typescript enums

[SwederellNF]

Version

1.49.1

Steps to reproduce

Clone repo: https://github.com/SwederellNF/enum-test
Run "npm install"
Run "npx playwright test"
Syntax error shown: "x Typescript enum is not supported in strip-only mode"

Expected behavior

It should run 1 example test.

Actual behavior

The following error is output to the 'Test Results' panel:

SyntaxError: x TypeScript enum is not supported in strip-only mode
,-[1:1]
1 | ,-> export enum TAGS {
2 | | test = "@testtag"
3 | -> } ----

Additional context

If you uninstall NodeJS 23.6.0 and install the current LTS version (22.13.0) version.

In version 23.6.0 the previously experimental flag was changed to default as below (from the release notes):

Unflagging --experimental-strip-types
This release enables the flag --experimental-strip-types by default.
Node.js will be able to execute TypeScript files without additional configuration:

node file.ts
There are some limitations in the supported syntax documented at https://nodejs.org/api/typescript.html#type-stripping
This feature is experimental and is subject to change.

Contributed by Marco Ippolito in nodejs/node#56350

Environment

System:
    OS: Windows 11 10.0.26100
    CPU: (12) x64 12th Gen Intel(R) Core(TM) i7-12850HX
    Memory: 1.46 GB / 4.87 GB
  Binaries:
    Node: 23.6.0 - C:\Program Files\nodejs\node.EXE
    npm: 11.0.0 - C:\Program Files\nodejs\npm.CMD
  IDEs:
    VSCode: 1.96.2 - C:\Users\Sam\AppData\Local\Programs\Microsoft VS Code\bin\code.CMD
  Languages:
    Bash: 5.2.37 - C:\Program Files\Git\usr\bin\bash.EXE
  npmPackages:
    @playwright/test: ^1.49.1 => 1.49.1

[Skn0tt]

This seems like more of a Node.js issue to me. Could you elaborate on why you think Playwright is at fault here? As a workaround, either remove the enum or use --experimental-transform-types.

[SwederellNF]

Taking out the enums isn’t really feasible. Will try the experimental transform flag and see if that works properly for what I’m doing. The point of the post was more about bringing it to the Playwright teams' attention that this issue is happening, rather than putting the blame on Playwright itself. I’m working on a GH issue for NodeJS as well.

[Skn0tt]

Thanks for bringing it to our attention. It's not an issue with Playwright and we can't do anything about it, so i'll close the issue.

[MarkusJLechner]

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)