GLSP-1693: Switch bundling to esbuild

.vscode/launch.json

@@ -77,9 +77,6 @@
         "${workspaceRoot}/examples/workflow-server/*/lib/**/*.js",
         "${workspaceRoot}/packages/**/*/lib/**/*.js"
       ],
-      "sourceMapPathOverrides": {
-        "webpack://@eclipse-glsp-examples/workflow-server/(.+)": "${workspaceFolder}/examples/workflow-server/$1"
-      },
       "smartStep": true,
       "internalConsoleOptions": "openOnSessionStart",
       "outputCapture": "std"
@@ -100,9 +97,6 @@
         "${workspaceRoot}/examples/workflow-server/*/lib/**/*.js",
         "${workspaceRoot}/packages/**/*/lib/**/*.js"
       ],
-      "sourceMapPathOverrides": {
-        "webpack://@eclipse-glsp-examples/workflow-server/(.+)": "${workspaceFolder}/examples/workflow-server/$1"
-      },
       "smartStep": true,
       "internalConsoleOptions": "openOnSessionStart",
       "outputCapture": "std"

.vscode/tasks.json

@@ -25,6 +25,17 @@
       },
       "problemMatcher": ["$tsc-watch"]
     },
+    {
+      "label": "Start Example GLSP server (dev, hot reload)",
+      "type": "shell",
+      "group": "none",
+      "command": "yarn dev",
+      "presentation": {
+        "reveal": "always",
+        "panel": "dedicated"
+      },
+      "problemMatcher": []
+    },
     {
       "label": "Execute all glsp-server tests",
       "type": "shell",

CLAUDE.md

@@ -10,8 +10,10 @@ Eclipse GLSP Server Node monorepo. Provides the TypeScript-based server framewor
 -   **Build**: `yarn` from root installs and compiles everything
 -   **Compile**: `yarn compile` (runs `tsc -b` with project references)
 -   **Clean**: `yarn clean`
--   **Watch**: `yarn watch` (parallel TypeScript + bundle watch)
--   **Start example server**: `yarn start` (TCP on 5007) or `yarn start:websocket` (WebSocket on 8081)
+-   **Watch**: `yarn watch` (parallel TypeScript + esbuild bundle watch)
+-   **Bundle**: `yarn bundle` (esbuild bundles the workflow example, node + webworker targets)
+-   **Start example server**: `yarn start` (TCP on 5007) or `yarn start:websocket` (WebSocket on 8081) — runs the pre-built bundle
+-   **Dev server (hot reload)**: `yarn dev` (TCP on 5007) or `yarn dev:ws` (WebSocket on 8081) — esbuild watches `src` and restarts the server on change
 
 ## Validation
 

examples/workflow-server-mcp-demo/.gitignore

@@ -1,2 +1,2 @@
-# Populated by `yarn start` (verbatim assets + synced worker bundle + webpack output)
+# Populated by `yarn start` (verbatim assets + synced worker bundle + esbuild output)
 dist/

examples/workflow-server-mcp-demo/esbuild.js

@@ -0,0 +1,75 @@
+/********************************************************************************
+ * Copyright (c) 2026 EclipseSource and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+// @ts-check
+const { resolve } = require('node:path');
+const esbuild = require('esbuild');
+
+const watch = process.argv.slice(2).includes('--watch');
+
+/**
+ * Reports the build progress and surfaces errors/warnings in a format that
+ * VS Code's `$esbuild-watch` problem matcher can pick up.
+ * @type {import('esbuild').Plugin}
+ */
+const esbuildProblemMatcherPlugin = {
+    name: 'esbuild-problem-matcher',
+    setup(build) {
+        build.onStart(() => {
+            console.log(`${watch ? '[watch] ' : ''}build started`);
+        });
+        build.onEnd(result => {
+            result.errors.forEach(({ text, location }) => {
+                console.error(`✘ [ERROR] ${text}`);
+                if (location) {
+                    console.error(`    ${location.file}:${location.line}:${location.column}:`);
+                }
+            });
+            console.log(`${watch ? '[watch] ' : ''}build finished`);
+        });
+    }
+};
+
+// Bundle `vscode-jsonrpc/browser` plus the page-side script into a single file emitted into
+// `dist/`, alongside the verbatim assets copied from `public/` and the worker bundle synced
+// from `@eclipse-glsp-examples/workflow-server-bundled-web` by `scripts/prepare-dist.mjs`.
+/** @type {import('esbuild').BuildOptions} */
+const config = {
+    entryPoints: [resolve(__dirname, 'src/index.js')],
+    outfile: resolve(__dirname, 'dist/index.bundle.js'),
+    bundle: true,
+    sourcemap: true,
+    platform: 'browser',
+    format: 'iife',
+    target: 'es2019',
+    mainFields: ['browser', 'module', 'main'],
+    conditions: ['browser'],
+    logLevel: 'silent',
+    plugins: [esbuildProblemMatcherPlugin]
+};
+
+async function main() {
+    if (watch) {
+        const ctx = await esbuild.context(config);
+        await ctx.watch();
+    } else {
+        await esbuild.build(config);
+    }
+}
+
+main().catch(e => {
+    console.error(e);
+    process.exit(1);
+});

examples/workflow-server-mcp-demo/package.json

@@ -14,7 +14,7 @@
     "name": "Eclipse GLSP"
   },
   "scripts": {
-    "build": "webpack",
+    "build": "node esbuild.js",
     "clean": "rimraf dist",
     "prestart": "node ./scripts/prepare-dist.mjs && yarn build",
     "start": "npx -y serve -l 8000 ./dist"
@@ -23,8 +23,7 @@
     "@eclipse-glsp-examples/workflow-server-bundled-web": "2.8.0-next"
   },
   "devDependencies": {
-    "vscode-jsonrpc": "8.2.0",
-    "webpack": "^5.75.0",
-    "webpack-cli": "^5.0.1"
+    "esbuild": "~0.28.0",
+    "vscode-jsonrpc": "8.2.0"
   }
 }

examples/workflow-server-mcp-demo/scripts/prepare-dist.mjs

@@ -14,10 +14,10 @@
  * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
  ********************************************************************************/
 
-// Populates `dist/` with everything `serve` needs that webpack doesn't emit:
+// Populates `dist/` with everything `serve` needs that esbuild doesn't emit:
 //  - verbatim files from `public/` (index.html, mcp-service-worker.js)
 //  - the worker bundle from `@eclipse-glsp-examples/workflow-server-bundled-web`
-// Webpack writes `index.bundle.js` into the same dir as a separate step.
+// esbuild writes `index.bundle.js` into the same dir as a separate step.
 
 import { copyFileSync, existsSync, mkdirSync, readdirSync, statSync } from 'node:fs';
 import { createRequire } from 'node:module';

examples/workflow-server/esbuild.js

@@ -0,0 +1,140 @@
+/********************************************************************************
+ * Copyright (c) 2022-2026 EclipseSource and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+// @ts-check
+const { spawn } = require('node:child_process');
+const { resolve } = require('node:path');
+const esbuild = require('esbuild');
+
+const argv = process.argv.slice(2);
+const watch = argv.includes('--watch');
+// Dev mode: build only the node target and (re)start the server after each successful build.
+const runNode = argv.includes('--run-node');
+// Everything after `--` is forwarded verbatim to the spawned node server (e.g. `--port 5007`).
+const dashDash = argv.indexOf('--');
+const serverArgs = dashDash >= 0 ? argv.slice(dashDash + 1) : [];
+
+const bundledDir = resolve(__dirname, '..', 'workflow-server-bundled');
+const bundledWebDir = resolve(__dirname, '..', 'workflow-server-bundled-web');
+
+/**
+ * Reports the build progress and surfaces errors/warnings in a format that
+ * VS Code's `$esbuild-watch` problem matcher can pick up.
+ * @type {import('esbuild').Plugin}
+ */
+const esbuildProblemMatcherPlugin = {
+    name: 'esbuild-problem-matcher',
+    setup(build) {
+        build.onStart(() => {
+            console.log(`${watch ? '[watch] ' : ''}build started`);
+        });
+        build.onEnd(result => {
+            result.errors.forEach(({ text, location }) => {
+                console.error(`✘ [ERROR] ${text}`);
+                if (location) {
+                    console.error(`    ${location.file}:${location.line}:${location.column}:`);
+                }
+            });
+            console.log(`${watch ? '[watch] ' : ''}build finished`);
+        });
+    }
+};
+
+/** @type {import('esbuild').BuildOptions} */
+const common = {
+    bundle: true,
+    // Minify one-shot production builds; keep watch/dev output readable and fast to rebuild.
+    // `sourcemap` still maps the (minified) output back to the original TypeScript sources.
+    minify: !watch,
+    // Preserve original class/function names through minification — GLSP's logger and error
+    // messages use `constructor.name` for labels, which would otherwise be mangled.
+    keepNames: true,
+    sourcemap: true,
+    logLevel: 'silent',
+    tsconfig: resolve(__dirname, 'tsconfig.json'),
+    plugins: [esbuildProblemMatcherPlugin]
+};
+
+/** @type {import('esbuild').BuildOptions} */
+const nodeConfig = {
+    ...common,
+    entryPoints: [resolve(__dirname, 'src/node/app.ts')],
+    outfile: resolve(bundledDir, 'wf-glsp-server-node.js'),
+    platform: 'node',
+    format: 'cjs',
+    target: 'node22',
+    // `ws` requires these optional native deps in a try/catch; keep them external so the
+    // graceful-fallback path works and esbuild does not error on the missing modules.
+    external: ['bufferutil', 'utf-8-validate']
+};
+
+/** @type {import('esbuild').BuildOptions} */
+const webworkerConfig = {
+    ...common,
+    entryPoints: [resolve(__dirname, 'src/browser/app.ts')],
+    outfile: resolve(bundledWebDir, 'wf-glsp-server-webworker.js'),
+    platform: 'browser',
+    format: 'iife',
+    target: 'es2019',
+    // Honor the legacy `browser` package field + browser condition for transitive deps.
+    mainFields: ['browser', 'module', 'main'],
+    conditions: ['browser']
+};
+
+/** Restart the bundled node server after every successful build. */
+function runNodePlugin() {
+    /** @type {import('node:child_process').ChildProcess | undefined} */
+    let child;
+    const stop = () => child?.kill('SIGTERM');
+    process.on('SIGINT', () => {
+        stop();
+        process.exit(0);
+    });
+    return {
+        name: 'run-node-server',
+        setup(build) {
+            build.onEnd(result => {
+                if (result.errors.length > 0) {
+                    // Keep the last good server running so a broken build does not crash the loop.
+                    return;
+                }
+                stop();
+                child = spawn('node', ['--enable-source-maps', nodeConfig.outfile, ...serverArgs], { stdio: 'inherit' });
+            });
+        }
+    };
+}
+
+async function run(config) {
+    if (watch) {
+        const ctx = await esbuild.context(config);
+        await ctx.watch();
+    } else {
+        await esbuild.build(config);
+    }
+}
+
+async function main() {
+    if (runNode) {
+        await run({ ...nodeConfig, plugins: [esbuildProblemMatcherPlugin, runNodePlugin()] });
+    } else {
+        await Promise.all([run(nodeConfig), run(webworkerConfig)]);
+    }
+}
+
+main().catch(e => {
+    console.error(e);
+    process.exit(1);
+});

examples/workflow-server/package.json

@@ -46,14 +46,15 @@
     "browser.js"
   ],
   "scripts": {
-    "build": "tsc -b && yarn bundle && yarn bundle:browser",
-    "bundle": "webpack",
-    "bundle:browser": "webpack --env target=webworker ",
+    "build": "tsc -b && yarn bundle",
+    "bundle": "node esbuild.js",
     "clean": "rimraf lib *.tsbuildinfo",
+    "dev": "node esbuild.js --watch --run-node -- --port 5007",
+    "dev:ws": "node esbuild.js --watch --run-node -- -w --port 8081",
     "generate:index": "glsp generateIndex src/browser src/common src/node -s -f",
     "lint": "eslint ./src",
     "watch": "tsc -w",
-    "watch:bundle": "webpack -w"
+    "watch:bundle": "node esbuild.js --watch"
   },
   "dependencies": {
     "@eclipse-glsp/layout-elk": "2.8.0-next",
@@ -62,9 +63,7 @@
     "inversify": "^6.1.3"
   },
   "devDependencies": {
-    "source-map-loader": "^4.0.1",
-    "webpack": "^5.75.0",
-    "webpack-cli": "^5.0.1"
+    "esbuild": "~0.28.0"
   },
   "publishConfig": {
     "access": "public"