regression: attempting to construct `DurableObjectState` in jest test causes parse error

[jorroll]

Attempting to construct an instance of DurableObjectState inside a jest test in a project using typescript fails with the following error:

    Jest encountered an unexpected token

    Jest failed to parse a file. This happens e.g. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is not configured to support such syntax.

    Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration.

    By default "node_modules" folder is ignored by transformers.

    Here's what you can do:
     • If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/ecmascript-modules for how to enable it.
     • If you are trying to use TypeScript, see https://jestjs.io/docs/getting-started#using-typescript
     • To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
     • If you need a custom transformation specify a "transform" option in your config.
     • If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.

    You'll find more details and examples of these config options in the docs:
    https://jestjs.io/docs/configuration
    For information about custom transformations, see:
    https://jestjs.io/docs/code-transformation

    Details:

    /workspaces/miniflare-typescript-esbuild-jest/node_modules/undici/lib/llhttp/llhttp.wasm:1
    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){
                                                                                      

    SyntaxError: Invalid or unexpected token

      at Runtime.createScriptFromCode (node_modules/jest-runtime/build/index.js:1728:14)

You can see a minimal reproduction by cloning this "durable-object-state-issue" repo branch (which also has an optional devcontainer)

• https://github.com/jorroll/miniflare-typescript-esbuild-jest/tree/durable-object-state-issue

Note that this repository was created using the "Miniflare Example Project" in the cloudflare docs. At first glance, this might seem like an issue with the example project's setup, however, unless I'm missing something, there shouldn't be any parse errors caused by a published package (in this case the @miniflare/durable-objects package).

Previously, ~~I think~~ I had success manually constructing an instance of DurableObjectState in order to unit test the non-fetch methods of a DurableObject (see #157)~~, however I cannot replicate this anymore~~.

[jorroll]

Note that the failing test campaign.spec.ts contains some comments on how to get the parse error to go away.

[jorroll]

Progress! This took forever to track down. Pinning the issue repo's package.json to:

  "devDependencies": {
    // ...
    "jest-environment-miniflare": "~2.2.0",
    "miniflare": "~2.2.0",
    "undici": "~4.12.0",
  }

Fixes the problem. It seems to be a regression caused by the undici dependency. This also explains why installing previous versions of miniflare alone didn't fix the issue (since previous versions of miniflare depended on version ^4.x of undici and so installed the latest version still). I'm not familiar with undici so I'm not sure if it's reasonable for it to cause a parse error in jest. The miniflare library shouldn't cause a parse error in jest though.

[mrbbot]

Hey! 👋 Thanks for raising this and apologies for the delayed response. This looks like an issue with undici/jest. Wonder if something like this might help? https://github.com/vuejs/vue-cli/issues/1584#issuecomment-399346455

[dan-lee]

Stumbled upon the same issue today. Unfortunately, neither transformIgnorePatterns nor `moduleNameMapper solved the issue for me.

[mrbbot]

Hey! 👋 You should be able to use the getMiniflareDurableObjectState() method released in 2.9.0 to construct DurableObjectStates: https://github.com/cloudflare/miniflare/releases/tag/v2.9.0.