Add npm build test to CI and fix broken build

[Copilot]

The npm build (deno task build:dist) was only run during publish, meaning build failures wouldn't be caught until release time.

Changes

• Added npm_build job to .github/workflows/test.yml with a Node.js smoke test to verify the artifact loads correctly
• Aligned configuration with publish.yml (same Deno version, setup action, permissions)
• Fixed pre-existing npm build failures:
  • Added a JSR resolver esbuild plugin to bundle @cross/runtime directly (instead of externalizing it, which would break npm consumers)
  • Created npm.ts as a Node.js-only entry point so only the Node.js shim is bundled (avoids including bun:test/Deno-specific static imports that would fail at load time in Node.js)
  • Removed CJS build (top-level await not supported in CommonJS format)
  • Removed dts-plugin (JSR type declarations unavailable during npm build)
  • Updated build/package.template.json to ESM-only exports referencing dist/npm.js
  • Excluded npm.ts from JSR publish

npm_build:
  runs-on: ubuntu-latest
  permissions:
    contents: read
  steps:
    - uses: actions/checkout@v4
    - name: Setup Deno
      uses: denoland/setup-deno@v1
      with:
        deno-version: v2.x
    - name: Build npm package
      run: deno task build:dist
    - name: Setup Node.js
      uses: actions/setup-node@v4
      with:
        node-version: "lts/*"
    - name: Smoke test Node artifact
      run: node -e "import('./dist/npm.js')"

Original prompt

Test npm build in ci, if it's not already done

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[Hexagon]

@copilot new build step actually failed, have a look

[Copilot]

@copilot new build step actually failed, have a look

Fixed in e42a035. The npm build was failing due to two issues:

1. @cross/runtime was not in esbuild's externals list
2. CJS build was failing because esbuild doesn't support top-level await in CommonJS format

The fix removes the CJS build (ESM-only now) and adds @cross/runtime to externals. Also removed the dts-plugin since JSR type declarations aren't available during the npm build.

[Copilot]

Pull request overview

This PR adds an npm build step to CI (so deno task build:dist failures are caught before release) and updates the build/package configuration to make the npm artifact ESM-only and avoid the previous build-time failures.

Changes:

• Added an npm_build job to .github/workflows/test.yml to run deno task build:dist on PRs/pushes.
• Updated build/build.ts to produce only an ESM Node bundle and to adjust esbuild externals.
• Updated build/package.template.json to publish ESM-only exports for the generated npm package.json.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
.github/workflows/test.yml	Adds an npm build job to CI to run deno task build:dist.
build/build.ts	Removes CJS + d.ts generation and switches to a single ESM build with updated externals.
build/package.template.json	Updates npm package metadata/exports to be ESM-only.

Comments suppressed due to low confidence (1)

build/build.ts:70

• The build command path no longer generates type declarations (the dts plugin/CJS build were removed), but the surrounding comment still says “Transpile and generate typings”. Updating this wording will help keep the build script’s guidance accurate.

  /* Handle argument `build`: Transpile and generate typings */
} else if (command === "build") {
  // Build the ESM JavaScript bundle

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[Copilot]

@cross/runtime is now marked as an esbuild external, which means the generated dist/mod.js will keep import "@cross/runtime" at runtime. The npm package template currently doesn’t declare any dependency/peerDependency on @cross/runtime, so consumers installing from npm will likely hit a Cannot find package '@cross/runtime' error unless they manually install it. Consider either bundling @cross/runtime (remove it from external) or adding it to the generated package.json (dependencies/peerDependencies) with a version aligned to deno.json.

Suggested change

	// @cross/runtime is a JSR dependency that must be externalized
	external: ["bun:test", "node:test", "@cross/runtime"],
	external: ["bun:test", "node:test"],

[Copilot]

The new npm_build job only checks that deno task build:dist completes. It doesn’t validate that the produced Node artifact can actually be loaded (e.g., a simple node -e "import('./dist/mod.js')" or importing the generated package entry). Adding a minimal runtime smoke-check here would catch externals/dependency mismatches that still allow bundling to succeed.

Suggested change

	run: deno task build:dist
	run: deno task build:dist
	- name: Setup Node.js
	uses: actions/setup-node@v4
	with:
	node-version: 'lts/*'
	- name: Smoke test Node artifact
	run: node -e "import('./dist/mod.js')"

[Hexagon]

@copilot apply changes based on the comments in this thread

[Copilot]

@copilot apply changes based on the comments in this thread

Applied both review suggestions in 41563b6:

1. @cross/runtime is now bundled (not external): Added a JSR resolver esbuild plugin that resolves @cross/runtime via Deno's module cache. Also created npm.ts as a Node.js-only entry point so only the Node.js shim is bundled (avoids including bun:test/Deno-specific imports that would fail at load time).

2. Smoke test added to the CI job: node -e "import('./dist/npm.js')" to verify the artifact loads correctly in Node.js.