fix: show warning when hot is enabled with HMR plugin in config

webpack · Aug 25, 2021 · 04f3914 · 04f3914
1 parent 13cd267
commit 04f3914
Showing 1 changed file with 12 additions and 8 deletions.
diff --git a/lib/Server.js b/lib/Server.js
@@ -1044,16 +1044,20 @@ class Server {
       // TODO remove after drop webpack v4 support
       compiler.options.plugins = compiler.options.plugins || [];
 
-      if (
-        this.options.hot &&
-        !compiler.options.plugins.find(
+      if (this.options.hot) {
+        const HMRPluginExists = compiler.options.plugins.find(
           (p) => p.constructor === webpack.HotModuleReplacementPlugin
-        )
-      ) {
-        // apply the HMR plugin, if it didn't exist before.
-        const plugin = new webpack.HotModuleReplacementPlugin();
+        );
 
-        plugin.apply(compiler);
+        if (HMRPluginExists) {
+          this.logger.warn(
+            `"hot: true" automatically applies HMR plugin, you don't have to add it manually to your webpack configuration.`
+          );
+        } else {
+          // apply the HMR plugin
+          const plugin = new webpack.HotModuleReplacementPlugin();
+          plugin.apply(compiler);
+        }
       }
     });