Add npm publish to release workflow

On git tag push (v*), builds Go binaries for all 4 platforms,
creates GitHub release, then publishes 6 npm packages:
@lightshell/{darwin-arm64,darwin-x64,linux-arm64,linux-x64},
lightshell, and create-lightshell. Version derived from tag.

Author: meherpanguluri

.github/workflows/release.yml

@@ -17,18 +17,22 @@ jobs:
             goos: darwin
             goarch: arm64
             artifact: lightshell-darwin-arm64
+            npm_pkg: darwin-arm64
           - os: macos-latest
             goos: darwin
             goarch: amd64
             artifact: lightshell-darwin-amd64
+            npm_pkg: darwin-x64
           - os: ubuntu-latest
             goos: linux
             goarch: amd64
             artifact: lightshell-linux-amd64
+            npm_pkg: linux-x64
           - os: ubuntu-latest
             goos: linux
             goarch: arm64
             artifact: lightshell-linux-arm64
+            npm_pkg: linux-arm64
 
     runs-on: ${{ matrix.os }}
 
@@ -95,3 +99,110 @@ jobs:
         with:
           generate_release_notes: true
           files: release/*.tar.gz
+
+  publish-npm:
+    needs: build
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          registry-url: https://registry.npmjs.org
+
+      - name: Download all artifacts
+        uses: actions/download-artifact@v4
+        with:
+          path: artifacts
+
+      - name: Get version from tag
+        id: version
+        run: echo "VERSION=${GITHUB_REF_NAME#v}" >> "$GITHUB_OUTPUT"
+
+      - name: Publish platform packages
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
+        run: |
+          VERSION=${{ steps.version.outputs.VERSION }}
+
+          declare -A BINARIES
+          BINARIES[darwin-arm64]=lightshell-darwin-arm64
+          BINARIES[darwin-x64]=lightshell-darwin-amd64
+          BINARIES[linux-x64]=lightshell-linux-amd64
+          BINARIES[linux-arm64]=lightshell-linux-arm64
+
+          declare -A OS_FIELD
+          OS_FIELD[darwin-arm64]=darwin
+          OS_FIELD[darwin-x64]=darwin
+          OS_FIELD[linux-x64]=linux
+          OS_FIELD[linux-arm64]=linux
+
+          declare -A CPU_FIELD
+          CPU_FIELD[darwin-arm64]=arm64
+          CPU_FIELD[darwin-x64]=x64
+          CPU_FIELD[linux-x64]=x64
+          CPU_FIELD[linux-arm64]=arm64
+
+          for PLATFORM in darwin-arm64 darwin-x64 linux-x64 linux-arm64; do
+            ARTIFACT=${BINARIES[$PLATFORM]}
+            PKG_DIR=$(mktemp -d)
+
+            cat > "$PKG_DIR/package.json" <<PKGJSON
+          {
+            "name": "@lightshell/${PLATFORM}",
+            "version": "${VERSION}",
+            "description": "LightShell binary for ${PLATFORM}",
+            "license": "MIT",
+            "repository": {
+              "type": "git",
+              "url": "https://github.com/meherpanguluri/lightshell"
+            },
+            "os": ["${OS_FIELD[$PLATFORM]}"],
+            "cpu": ["${CPU_FIELD[$PLATFORM]}"],
+            "files": ["lightshell"]
+          }
+          PKGJSON
+
+            cp "artifacts/${ARTIFACT}/${ARTIFACT}" "$PKG_DIR/lightshell"
+            chmod +x "$PKG_DIR/lightshell"
+
+            echo "Publishing @lightshell/${PLATFORM}@${VERSION}"
+            cd "$PKG_DIR" && npm publish --access public || true
+            cd -
+          done
+
+      - name: Publish main lightshell package
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
+        run: |
+          VERSION=${{ steps.version.outputs.VERSION }}
+          cd npm/lightshell
+
+          # Update version and optional dependency versions
+          node -e "
+            const pkg = require('./package.json');
+            pkg.version = '${VERSION}';
+            for (const dep of Object.keys(pkg.optionalDependencies || {})) {
+              pkg.optionalDependencies[dep] = '${VERSION}';
+            }
+            require('fs').writeFileSync('package.json', JSON.stringify(pkg, null, 2) + '\n');
+          "
+
+          npm publish --access public
+
+      - name: Publish create-lightshell package
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
+        run: |
+          VERSION=${{ steps.version.outputs.VERSION }}
+          cd npm/create-lightshell
+
+          node -e "
+            const pkg = require('./package.json');
+            pkg.version = '${VERSION}';
+            require('fs').writeFileSync('package.json', JSON.stringify(pkg, null, 2) + '\n');
+          "
+
+          npm publish --access public

npm/lightshell/install.js

@@ -0,0 +1,52 @@
+#!/usr/bin/env node
+
+// Postinstall script: copy the platform-specific binary to bin/
+const { platform, arch } = process;
+const path = require("path");
+const fs = require("fs");
+
+const platformMap = {
+  darwin: "darwin",
+  linux: "linux",
+};
+
+const archMap = {
+  arm64: "arm64",
+  x64: "x64",
+  x86_64: "x64",
+};
+
+const os = platformMap[platform];
+const cpu = archMap[arch];
+
+if (!os || !cpu) {
+  console.error(
+    `lightshell: unsupported platform ${platform}-${arch}. Only macOS and Linux (arm64, x64) are supported.`
+  );
+  process.exit(1);
+}
+
+const pkgName = `@lightshell/${os}-${cpu}`;
+
+let binaryPath;
+try {
+  binaryPath = require.resolve(`${pkgName}/lightshell`);
+} catch {
+  console.error(
+    `lightshell: could not find ${pkgName}. Make sure optional dependencies are installed.\n` +
+      `Try: npm install --include=optional`
+  );
+  process.exit(1);
+}
+
+const binDir = path.join(__dirname, "bin");
+const dest = path.join(binDir, "lightshell");
+
+try {
+  fs.mkdirSync(binDir, { recursive: true });
+  fs.copyFileSync(binaryPath, dest);
+  fs.chmodSync(dest, 0o755);
+} catch (err) {
+  console.error(`lightshell: failed to install binary: ${err.message}`);
+  process.exit(1);
+}

npm/lightshell/package.json

@@ -0,0 +1,27 @@
+{
+  "name": "lightshell",
+  "version": "0.1.0",
+  "description": "Build desktop apps with JavaScript. Ship them under 5MB.",
+  "keywords": ["desktop", "app", "framework", "webview", "native", "macos", "linux"],
+  "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/meherpanguluri/lightshell"
+  },
+  "homepage": "https://lightshell.sh",
+  "bin": {
+    "lightshell": "bin/lightshell"
+  },
+  "scripts": {
+    "postinstall": "node install.js"
+  },
+  "optionalDependencies": {
+    "@lightshell/darwin-arm64": "0.1.0",
+    "@lightshell/darwin-x64": "0.1.0",
+    "@lightshell/linux-arm64": "0.1.0",
+    "@lightshell/linux-x64": "0.1.0"
+  },
+  "engines": {
+    "node": ">=16"
+  }
+}