perf(worker-rust): Add `dev` env for faster local build times

[futile]

What this PR solves / how to test:

Add a dev-environment to wrangler.toml which builds with worker-build --dev instead of worker-build --release. This makes build times for local development much faster.

Add opt-level = "s" to Cargo.toml so release builds are optimized for size.

Remove the deprecated --local parameter from the wrangler invocation.

Author has addressed the following:

Not sure which of these I should do (and how).

• Tests
  • [ ] Included
  • [x] Not necessary because: basic configuration change in a template
• Changeset (Changeset guidelines)
  • [ ] Included
  • [x] Not necessary because: we don't have changesets for templates??
• Associated docs
  • [ ] Issue(s)/PR(s): do we need to update some docs??
  • [ ] Not necessary because:

[changeset-bot[bot]]

⚠️ No Changeset found

Latest commit: 75114c5a4f32b2a07628517e47055f35562136de

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[github-actions[bot]]

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/7973227046/npm-package-wrangler-5059

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

npm install --save-dev https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/prs/5059/npm-package-wrangler-5059

Or you can use npx with this latest build directly:

npx https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/7973227046/npm-package-wrangler-5059 dev path/to/script.js

Additional artifacts:

npx https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/7973227046/npm-package-create-cloudflare-5059 --no-auto-update

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/7973227046/npm-package-cloudflare-kv-asset-handler-5059

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/7973227046/npm-package-miniflare-5059

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/7973227046/npm-package-cloudflare-pages-shared-5059

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/7973227046/npm-package-cloudflare-vitest-pool-workers-5059

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:*	3.20240129.3
workerd	1.20240129.0	1.20240129.0
workerd --version	1.20240129.0	2024-01-29

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

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 70.38%. Comparing base (01e0846) to head (75114c5). Report is 48 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5059      +/-   ##
==========================================
+ Coverage   70.34%   70.38%   +0.04%     
==========================================
  Files         298      298              
  Lines       15463    15463              
  Branches     3966     3966              
==========================================
+ Hits        10877    10884       +7     
+ Misses       4586     4579       -7     

see 6 files with indirect coverage changes

[futile]

Thanks for the review! One thing I'm not sure about: Removing the --local flag. This might fail with older wrangler-versions now, I think? Should I remove it again from this PR?

But then again, this template will probably be used with more recent versions of wrangler (since a template is usually used for new projects), so it might just be fine in this case.

[Skye-31]

Wrangler 3, when the change to default to local mode occurred, has been out for ~9 months, so personally I wouldn't be too concerned about the change

[futile]

Awesome, thanks! :)

[petebacondarwin]

Do we need to update some docs somewhere to match this change?

[futile]

One other point I realized: Is opt-level = "s" for release-builds desired by default? Since it won't be running in the frontend/not downloaded by browsers, maybe this doesn't actually make that much sense?

I added it originally because it's a very common optimization for wasm use-cases, but maybe that doesn't really count for workers.

[petebacondarwin]

I'm no Rust specialist so I would bow to your (or anyone else's views) but I would note that Workers still have a size limit on what can be deployed. So it might be worth keeping a size optimisation turned on?

[futile]

I'm no Rust specialist so I would bow to your (or anyone else's views) but I would note that Workers still have a size limit on what can be deployed. So it might be worth keeping a size optimisation turned on?

That's a good point. I think optimizing for size by default should be sensible for wasm-builds (like in this case), and users can still change/adapt this later on anyways.

So if it's up to me I would keep the opt-level = "s", but feel free to let me know if I should change it :)

[Skye-31]

That seems reasonable to keep IMO