feat: update WebSocket communication conditions and multi-compiler fallback logic

Author: bjohansebas

lib/Server.js

@@ -560,9 +560,7 @@ class Server {
    * @returns {boolean} true when target is `web`, otherwise false
    */
   static isWebTarget(compiler) {
-    return (
-      compiler.platform?.web || compiler.options.externalsPresets?.web || false
-    );
+    return compiler.platform?.web || false;
   }
 
   /**
@@ -778,12 +776,7 @@ class Server {
       // Configuration with `web` preset
       const compilerWithWebPreset =
         /** @type {MultiCompiler} */
-        (this.compiler).compilers.find(
-          (config) =>
-            config.options.externalsPresets?.web ||
-            config.platform?.web ||
-            false,
-        );
+        (this.compiler).compilers.find((config) => Server.isWebTarget(config));
 
       if (compilerWithWebPreset) {
         return compilerWithWebPreset.options;

migration-v6.md

@@ -37,9 +37,9 @@ This document serves as a migration guide for `webpack-dev-server@6.0.0`.
   };
   ```
 
-- Now, webpack-dev-server adds WebSocket communication only when the `target` is set to a web-compatible environment or when `externalsPresets` includes `web`.
+- Now, webpack-dev-server adds WebSocket communication only when the `target` is set to a web-compatible environment. Previously, it also injected WebSocket communication if `resolve` contained a `conditionNames` entry with `browser` or if `externalsPresets.web` existed.
 
-Previously, it also injected WebSocket communication if `resolve` contained a `conditionNames` entry with `browser`.
+- When retrieving the configuration in a multi-compiler setup, it will look for one that has a target compatible with a web environment. If it doesn’t find one, it will fall back to the first compiler found by webpack.
 
 ## Deprecations