feat(miniflare): Implement KV/Assets plugin and Workers Assets simulator

[CarmenPopoviciu]

What this PR solves / how to test

This commit extends Miniflare's KV plugin's behaviour to support Workers assets, and therefore enables the emulation of Workers with assets in local development.

Fixes WC-2394

Author has addressed the following

• Tests
  • TODO (before merge)
  • Included
  • Not necessary because:
• E2E Tests CI Job required? (Use "e2e" label or ask maintainer to run separately)
  • I don't know
  • Required / Maybe required
  • Not required because: miniflare changes
• Changeset (Changeset guidelines)
  • TODO (before merge)
  • Included
  • Not necessary because:
• Public documentation
  • TODO (before merge)
  • Cloudflare docs PR(s):
  • Not necessary because: experimental feature

[changeset-bot]

🦋 Changeset detected

Latest commit: 9c0098e

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

This PR includes changesets to release 5 packages

Name	Type
miniflare	Minor
@cloudflare/workers-shared	Minor
@cloudflare/pages-shared	Patch
@cloudflare/vitest-pool-workers	Patch
wrangler	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[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/10401949551/npm-package-wrangler-6403

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

npm install --save-dev https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/prs/6403/npm-package-wrangler-6403

Or you can use npx with this latest build directly:

npx https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/10401949551/npm-package-wrangler-6403 dev path/to/script.js

Additional artifacts:

npx https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/10401949551/npm-package-create-cloudflare-6403 --no-auto-update

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/10401949551/npm-package-cloudflare-kv-asset-handler-6403

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/10401949551/npm-package-miniflare-6403

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/10401949551/npm-package-cloudflare-pages-shared-6403

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/10401949551/npm-package-cloudflare-vitest-pool-workers-6403

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/10401949551/npm-package-cloudflare-workers-editor-shared-6403

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/10401949551/npm-package-cloudflare-workers-shared-6403

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

---

[email protected] includes the following runtime dependencies:

Package	Constraint	Resolved
miniflare	workspace:*	3.20240806.0
workerd	1.20240806.0	1.20240806.0
workerd --version	1.20240806.0	2024-08-06

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

[CarmenPopoviciu]

@petebacondarwin this is ready to re-review

[petebacondarwin]

Let's get this in and iterate next week.