Prioritise workerd condition when bundling

[mrbbot]

What this PR solves / how to test:

This PR adds support for the workerd condition when bundling Worker code. This can be used to implement isomorphic libraries that work with different JavaScript runtimes. workerd is the standard key for the Cloudflare Workers runtime: https://runtime-keys.proposal.wintercg.org/#workerd.

To test this PR, run npx wrangler dev in the fixtures/worker-app directory, and visit http://127.0.0.1:8787/random in your browser. Note that random data appears. We haven't enabled Node.js compatibility so we must be using the workerd version of the isomorphic-random-example package.

Associated docs issues/PR:

• [Workers] Add Wrangler docs for conditional exports cloudflare-docs#7424

Author has included the following, where applicable:

• Tests
• Changeset

Reviewer has performed the following, where applicable:

• Checked for inclusion of relevant tests
• Checked for inclusion of a relevant changeset
• Checked for creation of associated docs updates
• Manually pulled down the changes and spot-tested

[changeset-bot]

🦋 Changeset detected

Latest commit: fc3d4a7

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

This PR includes changesets to release 1 package

Name	Type
wrangler	Minor

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/runs/4025095389/npm-package-wrangler-2629

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

npm install --save-dev https://prerelease-registry.devprod.cloudflare.dev/prs/2629/npm-package-wrangler-2629

Or you can use npx with this latest build directly:

npx https://prerelease-registry.devprod.cloudflare.dev/runs/4025095389/npm-package-wrangler-2629 dev path/to/script.js

Additional artifacts:

npm install https://prerelease-registry.devprod.cloudflare.dev/runs/4025095389/npm-package-cloudflare-pages-shared-2629

[GregBrimble]

Super cool!

[codecov]

Codecov Report

Merging #2629 (fc3d4a7) into main (04d8a31) will increase coverage by 0.03%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #2629      +/-   ##
==========================================
+ Coverage   73.32%   73.35%   +0.03%     
==========================================
  Files         159      159              
  Lines        9852     9852              
  Branches     2627     2627              
==========================================
+ Hits         7224     7227       +3     
+ Misses       2628     2625       -3     

Impacted Files	Coverage Δ
packages/wrangler/src/bundle.ts	90.33% <ø> (ø)
packages/wrangler/src/git-client.ts	81.25% <0.00%> (+4.16%)	⬆️
...ackages/wrangler/src/__tests__/helpers/mock-bin.ts	100.00% <0.00%> (+5.26%)	⬆️

[petebacondarwin]

LGTM - personally I would prefer a bit more explanation in the changeset file, since this is what will appear in the changelog as documentation. For example you could add this sentence from the PR description:

This can be used to implement isomorphic libraries that work with different JavaScript runtimes. workerd is the standard key for the Cloudflare Workers runtime: https://runtime-keys.proposal.wintercg.org/#workerd.

[penalosa]

This looks great! What about adding an e2e test, as well?

[jasnell]

Awesome.