fix: send hmr status per platform when more than one webpack processes are stated (#690)

Author: Fatme

lib/compiler.js

@@ -82,9 +82,11 @@ exports.runWebpackCompiler = function runWebpackCompiler(config, $projectData, $
 
                     const result = getUpdatedEmittedFiles(message.emittedFiles);
 
-                    if (hookArgs.hmrData && hookArgs.hmrData.fallbackFiles) {
-                        hookArgs.hmrData.fallbackFiles[platform] = result.fallbackFiles;
-                        hookArgs.hmrData.hash = result.hash || "";
+                    if (hookArgs.hmrData) {
+                        hookArgs.hmrData[platform] = {
+                            hash: result.hash || "",
+                            fallbackFiles: result.fallbackFiles
+                        };
                     }
 
                     if (hookArgs.filesToSyncMap && hookArgs.startSyncFilesTimeout) {