fix: allow assets in multiworker setup

[emily-shen]

#7251 will allow running multiple workers in one Miniflare instance. Currently we only set up the router/asset worker for the first worker passed to miniflare, assuming this will be the only user worker. This PR will make sure assets works regardless of how many 'user workers' are passed in and at what point.

---

• Tests
  • TODO (before merge): once Support multiple workers in a single Miniflare instance #7251 is in.
  • Tests included
  • Tests not necessary because:
• E2E Tests CI Job required? (Use "e2e" label or ask maintainer to run separately)
  • I don't know
  • Required
  • Not required because:
• Public documentation
  • TODO (before merge)
  • Cloudflare docs PR(s):
  • Documentation not necessary because: I don't think there are any existing docs covering this.

[changeset-bot]

🦋 Changeset detected

Latest commit: 24463da

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

This PR includes changesets to release 5 packages

Name	Type
miniflare	Patch
wrangler	Patch
@cloudflare/pages-shared	Patch
@cloudflare/vite-plugin	Patch
@cloudflare/vitest-pool-workers	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.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-wrangler-7290

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

npm install --save-dev https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/prs/7290/npm-package-wrangler-7290

Or you can use npx with this latest build directly:

npx https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-wrangler-7290 dev path/to/script.js

Additional artifacts:

cloudflare-workers-bindings-extension:

wget https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-cloudflare-workers-bindings-extension-7290 -O ./cloudflare-workers-bindings-extension.0.0.0-v367f0ce0d.vsix && code --install-extension ./cloudflare-workers-bindings-extension.0.0.0-v367f0ce0d.vsix

create-cloudflare:

npx https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-create-cloudflare-7290 --no-auto-update

@cloudflare/kv-asset-handler:

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-cloudflare-kv-asset-handler-7290

miniflare:

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-miniflare-7290

@cloudflare/pages-shared:

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-cloudflare-pages-shared-7290

@cloudflare/unenv-preset:

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-cloudflare-unenv-preset-7290

@cloudflare/vite-plugin:

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-cloudflare-vite-plugin-7290

@cloudflare/vitest-pool-workers:

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-cloudflare-vitest-pool-workers-7290

@cloudflare/workers-editor-shared:

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-cloudflare-workers-editor-shared-7290

@cloudflare/workers-shared:

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-cloudflare-workers-shared-7290

@cloudflare/workflows-shared:

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/13205502548/npm-package-cloudflare-workflows-shared-7290

Note that these links will no longer work once the GitHub Actions artifact expires.

---

wrangler@3.107.3 includes the following runtime dependencies:

Package	Constraint	Resolved
miniflare	workspace:*	3.20250129.0
workerd	1.20250204.0	1.20250204.0
workerd --version	1.20250204.0	2025-02-04

Please ensure constraints are pinned, and miniflare/workerd minor versions match.

[penalosa]

Is that how this works in production? I'd have expected service bindings to bypass the router worker

[emily-shen]

yeah production behaviour seriously confused me at first but fetch on a service binding does definitely hit assets, even if it is a binding to a named entrypoint.

	prod (ie expected behaviour)
Simple fetch handler	assets / UW
Fetch on default worker entrypoint	Assets / UW
RPC on default entrypoint	UW only
Fetch on named entrypoint	Assets / UW's named entrypoint UW only
RPC on named entrypoint	UW only

Edit for posterity:

Fetch on named entrypoint | Assets / UW's named entrypoint

this is a bug! that makes so much more sense!!

[penalosa]

Could we add some tests for this? i.e. in https://github.com/cloudflare/workers-sdk/blob/80a83bb4708ea2e3d4b514d3ebc97aa40c14439c/packages/wrangler/e2e/multiworker-dev.test.ts. In particular it would be good to have a test that validates that RPC service bindings bypass Assets

[emily-shen]

47a09dab086217fc873658567cde510f914c9a2a

[penalosa]

Some small comments, but overall 🎉