fix: restore externalized Node.js dep compatibility (#3421)

* fix: restore externalized Node.js dep compatibility

Restore the ability to build Undici compatible with Node.js'
`configure --shared-builtin-undici/undici-path ...` build option.

Scopes the `hasApk` conditional to only cover the part that requires
`apk`.

Makes the WASM optimizer (binaryen) optional to allow building on
Linux distributions that do not package `binaryen` and must be able
to rebuild everything (including tooling) from source.

* ci: add workflow for externalized Node.js dep

Add a workflow to test building Undici in a way compatible with Node.js
built with `configure --shared-builtin-undici/undici-path ...`.

This configuration is used by downstream Node.js packagers (e.g. Fedora)
who require the ability to be able to build everything from source.

.github/workflows/nodejs-shared.yml

@@ -0,0 +1,102 @@
+name: Node.js compiled --shared-builtin-undici/undici-path CI
+
+on:
+  push:
+    branches:
+     - main
+     - current
+     - next
+     - 'v*'
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  test-shared-builtin:
+    name: Test with Node.js ${{ matrix.version }} compiled --shared-builtin-undici/undici-path
+    strategy:
+      fail-fast: false
+      max-parallel: 0
+      matrix:
+        version: [20, 22]
+    runs-on: ubuntu-latest
+    timeout-minutes: 120
+    steps:
+      # Checkout into a subdirectory otherwise Node.js tests will break due to finding Undici's package.json in a parent directory.
+      - name: Checkout
+        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633 # v4.1.2
+        with:
+          path: ./undici
+          persist-credentials: false
+
+      # Setup node, install deps, and build undici prior to building node with `--shared-builtin-undici/undici-path` and testing
+      - name: Setup Node.js@${{ inputs.version }}
+        uses: actions/setup-node@60edb5dd545a775178f52524783378180af0d1f8 # v4.0.2
+        with:
+          node-version: ${{ inputs.version }}
+
+      - name: Install dependencies
+        working-directory: ./undici
+        run: npm install
+
+      - name: Install wasi-libc
+        run: sudo apt-get install -y wasi-libc
+
+      - name: Build WASM
+        working-directory: ./undici
+        run: |
+          export EXTERNAL_PATH=${{ github.workspace }}/undici
+          export WASM_CC=clang
+          export WASM_CFLAGS='--target=wasm32-wasi --sysroot=/usr'
+          export WASM_LDFLAGS='-nodefaultlibs'
+          export WASM_LDLIBS='-lc'
+          node build/wasm.js
+
+      - name: Determine latest release
+        id: release
+        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        with:
+          result-encoding: string
+          script: |
+            const req = await fetch('https://nodejs.org/download/release/index.json')
+            const releases = await req.json()
+
+            const latest = releases.find((r) => r.version.startsWith('v${{ matrix.version }}'))
+            return latest.version
+
+      - name: Download and extract source
+        run: curl https://nodejs.org/download/release/${{ steps.release.outputs.result }}/node-${{ steps.release.outputs.result }}.tar.xz | tar xfJ -
+
+      - name: Install ninja
+        run: sudo apt-get install ninja-build
+
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@c92f40bee50034e84c763e33b317c77adaa81c92 #v1.2.13
+        with:
+          key: node(external_undici)${{ matrix.version }}
+
+      - name: Build node
+        working-directory: ./node-${{ steps.release.outputs.result }}
+        run: |
+          export CC="ccache gcc"
+          export CXX="ccache g++"
+          rm -rf deps/undici
+          ./configure --shared-builtin-undici/undici-path ${{ github.workspace }}/undici/loader.js --ninja --prefix=./final
+          make
+          make install
+          echo "$(pwd)/final/bin" >> $GITHUB_PATH
+
+      - name: Print version information
+        run: |
+          echo OS: $(node -p "os.version()")
+          echo Node.js: $(node --version)
+          echo npm: $(npm --version)
+          echo git: $(git --version)
+          echo external config: $(node -e "console.log(process.config)" | grep NODE_SHARED_BUILTIN_UNDICI_UNDICI_PATH)
+          echo Node.js built-in undici version: $(node -p "process.versions.undici") # undefined for external Undici
+
+      - name: Run tests
+        working-directory: ./node-${{ steps.release.outputs.result }}
+        run: tools/test.py -p dots --flaky-tests=dontcare
+

CONTRIBUTING.md

@@ -156,7 +156,8 @@ If you are packaging `undici` for a distro, this might help if you would like to
 an unbundled version instead of bundling one in `libnode.so`.
 
 To enable this, pass `EXTERNAL_PATH=/path/to/global/node_modules/undici` to `build/wasm.js`.
-You shall also pass this path to `--shared-builtin-undici/undici-path` in Node.js's `configure.py`.
+Pass this path with `loader.js` appended to `--shared-builtin-undici/undici-path` in Node.js's `configure.py`.
+If building on a non-Alpine Linux distribution, you may need to also set the `WASM_CC`, `WASM_CFLAGS`, `WASM_LDFLAGS` and `WASM_LDLIBS` environment variables before running `build/wasm.js`.
 
 <a id="benchmarks"></a>
 ### Benchmarks

build/wasm.js

@@ -15,6 +15,9 @@ let WASM_CFLAGS = process.env.WASM_CFLAGS || '--sysroot=/usr/share/wasi-sysroot
 let WASM_LDFLAGS = process.env.WASM_LDFLAGS || ''
 const WASM_LDLIBS = process.env.WASM_LDLIBS || ''
 
+// For compatibility with Node.js' `configure --shared-builtin-undici/undici-path ...`
+const EXTERNAL_PATH = process.env.EXTERNAL_PATH
+
 // These are relevant for undici and should not be overridden
 WASM_CFLAGS += ' -Ofast -fno-exceptions -fvisibility=hidden -mexec-model=reactor'
 WASM_LDFLAGS += ' -Wl,-error-limit=0 -Wl,-O3 -Wl,--lto-O3 -Wl,--strip-all'
@@ -73,6 +76,9 @@ if (process.argv[2] === '--docker') {
 const hasApk = (function () {
   try { execSync('command -v apk'); return true } catch (error) { return false }
 })()
+const hasOptimizer = (function () {
+  try { execSync('./wasm-opt --version'); return true } catch (error) { return false }
+})()
 if (hasApk) {
   // Gather information about the tools used for the build
   const buildInfo = execSync('apk info -v').toString()
@@ -81,24 +87,38 @@ if (hasApk) {
     process.exit(-1)
   }
   console.log(buildInfo)
+}
 
-  // Build wasm binary
-  execSync(`${WASM_CC} ${WASM_CFLAGS} ${WASM_LDFLAGS} \
-  ${join(WASM_SRC, 'src')}/*.c \
-  -I${join(WASM_SRC, 'include')} \
-  -o ${join(WASM_OUT, 'llhttp.wasm')} \
-  ${WASM_LDLIBS}`, { stdio: 'inherit' })
+// Build wasm binary
+execSync(`${WASM_CC} ${WASM_CFLAGS} ${WASM_LDFLAGS} \
+${join(WASM_SRC, 'src')}/*.c \
+-I${join(WASM_SRC, 'include')} \
+-o ${join(WASM_OUT, 'llhttp.wasm')} \
+${WASM_LDLIBS}`, { stdio: 'inherit' })
 
+if (hasOptimizer) {
   execSync(`./wasm-opt ${WASM_OPT_FLAGS} -o ${join(WASM_OUT, 'llhttp.wasm')} ${join(WASM_OUT, 'llhttp.wasm')}`, { stdio: 'inherit' })
-  writeWasmChunk('llhttp.wasm', 'llhttp-wasm.js')
+}
+writeWasmChunk('llhttp.wasm', 'llhttp-wasm.js')
 
-  // Build wasm simd binary
-  execSync(`${WASM_CC} ${WASM_CFLAGS} -msimd128 ${WASM_LDFLAGS} \
-  ${join(WASM_SRC, 'src')}/*.c \
-  -I${join(WASM_SRC, 'include')} \
-  -o ${join(WASM_OUT, 'llhttp_simd.wasm')} \
-  ${WASM_LDLIBS}`, { stdio: 'inherit' })
+// Build wasm simd binary
+execSync(`${WASM_CC} ${WASM_CFLAGS} -msimd128 ${WASM_LDFLAGS} \
+${join(WASM_SRC, 'src')}/*.c \
+-I${join(WASM_SRC, 'include')} \
+-o ${join(WASM_OUT, 'llhttp_simd.wasm')} \
+${WASM_LDLIBS}`, { stdio: 'inherit' })
 
+if (hasOptimizer) {
   execSync(`./wasm-opt ${WASM_OPT_FLAGS} --enable-simd -o ${join(WASM_OUT, 'llhttp_simd.wasm')} ${join(WASM_OUT, 'llhttp_simd.wasm')}`, { stdio: 'inherit' })
-  writeWasmChunk('llhttp_simd.wasm', 'llhttp_simd-wasm.js')
+}
+writeWasmChunk('llhttp_simd.wasm', 'llhttp_simd-wasm.js')
+
+// For compatibility with Node.js' `configure --shared-builtin-undici/undici-path ...`
+if (EXTERNAL_PATH) {
+  writeFileSync(join(ROOT, 'loader.js'), `
+'use strict'
+globalThis.__UNDICI_IS_NODE__ = true
+module.exports = require('node:module').createRequire('${EXTERNAL_PATH}/loader.js')('./index-fetch.js')
+delete globalThis.__UNDICI_IS_NODE__
+`)
 }