chore: use plugin support

.changeset/dev-server-6-plugin.md

@@ -0,0 +1,5 @@
+---
+"webpack-cli": minor
+---
+
+feat: add support for `webpack-dev-server@6`. When v6 is installed, `webpack serve` runs the dev server as a compiler plugin: the CLI drives the compilation in watch mode, prints the build stats itself and owns graceful shutdown (`SIGINT`/`SIGTERM` close the compiler, which stops the server through its `shutdown` hook), and port conflicts between multiple `devServer` configurations are reported before any server starts listening. `webpack-dev-server@5` keeps working through its own compilation flow.

.github/workflows/nodejs.yml

@@ -63,7 +63,7 @@ jobs:
         os: [ubuntu-latest, windows-latest, macos-latest]
         node-version: [20.x, 22.x, 24.x, 25.x]
         webpack-version: [latest]
-        dev-server-version: [latest]
+        dev-server-version: [5, latest]
 
     steps:
       - name: Checkout code
@@ -85,6 +85,10 @@ jobs:
       - name: Install dependencies
         run: npm ci --ignore-scripts
 
+      - name: Install webpack-dev-server ${{ matrix.dev-server-version }}
+        if: matrix.dev-server-version == '5'
+        run: npm install webpack-dev-server@${{ matrix.dev-server-version }} --no-save --ignore-scripts
+
       - name: Prepare environment for tests
         run: npm run build -- --sourceMap true
 

.prettierignore

@@ -11,6 +11,7 @@ test/build/config/error-commonjs/syntax-error.js
 test/build/config/error-array/webpack.config.js
 test/build/config/error-mjs/syntax-error.mjs
 test/configtest/with-config-path/syntax-error.config.js
+test/serve/error-handling/src/syntax-error.js
 test/build/build-errors/stats.json
 
 /.nx/workspace-data

eslint.config.mjs

@@ -17,6 +17,7 @@ export default defineConfig([
     "test/configtest/with-config-path/syntax-error.config.js",
     "test/build/config-format/auto/webpack.config.js",
     "test/build/config-format/typescript-tsx/webpack.config.jsx",
+    "test/serve/error-handling/src/syntax-error.js",
   ]),
   {
     extends: [config],