[WIP] Error if a user tries to use durable objects with a service worker

[caass]

Durable Objects require Module Workers to function, so we should error if we discover that a user is trying to use a durable object with a Service Worker.

Closes #635

[changeset-bot]

🦋 Changeset detected

Latest commit: e0935f2

The changes in this PR will be included in the next version bump.

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wrangler	Patch

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[github-actions]

A wrangler prerelease is available for testing. You can install this latest build in your project with:

npm install --save-dev https://prerelease-registry.developers.workers.dev/runs/2001973798/npm-package-wrangler-634

You can reference the automatically updated head of this PR with:

npm install --save-dev https://prerelease-registry.developers.workers.dev/prs/634/npm-package-wrangler-634

Or you can use npx with this latest build directly:

npx https://prerelease-registry.developers.workers.dev/runs/2001973798/npm-package-wrangler-634 dev path/to/script.js

[Electroid]

There is a little more nuance: modules are required to implement a Durable Object, but not to bind to one. Therefore, it’s only an error when the format is service worker and the Durable Object binding does not have a “script_name”.

[caass]

There is a little more nuance: modules are required to implement a Durable Object, but not to bind to one. Therefore, it’s only an error when the format is service worker and the Durable Object binding does not have a “script_name”.

Ah ok...so actually...the real error is that a worker cannot have both addEventListener and an export?

So like...is this legal?

EDIT: no, i don't think it is because you still need to export DurableObjectExample from index.js

durable_object.js

export class DurableObjectExample {
    constructor(state, env) {
    }

    async fetch(request) {
        return new Response('Hello World');
    }

}

index.js

addEventListener('fetch', event => {
  const example = EXAMPLE_CLASS.get('some-id');
 // ...
})

wrangler.toml

# ...
main = "index.js"
[durable_objects]
bindings = [
  { name = "EXAMPLE_CLASS", class_name = "DurableObjectExample", script_name = "durable_object.js" }
]

[caass]

Closing this PR and copying over discussion to the issue until I've figured out a better way to check for this