fix(renderer): ensure tab content visibility after file open

- Add missing updateUI() call at end of openFile() to set .active class
  on tab content. Without this, the CSS rule .tab-content:not(.active)
  { display: none } kept newly opened files invisible.
- Add diagnostic logging to file-opened IPC handler and openFile()
  to trace future file loading issues.
- Add diagnostic logging to openFileFromPath() in main process.

Amit Haridas

src/main.js

@@ -3759,7 +3759,7 @@ app.on('open-file', (event, filePath) => {
 // Handle file opening from command line or file association
 function openFileFromPath(filePath) {
   console.log('[MAIN] openFileFromPath called with:', filePath);
-  console.log('[MAIN] rendererReady:', rendererReady, 'mainWindow exists:', !!mainWindow);
+  console.log('[MAIN] rendererReady:', rendererReady, 'mainWindow exists:', !!mainWindow, 'webContents exists:', !!(mainWindow?.webContents));
   if (fs.existsSync(filePath)) {
     const stats = fs.statSync(filePath);
     if (stats.size > MAX_FILE_SIZE) {
@@ -3769,6 +3769,7 @@ function openFileFromPath(filePath) {
     currentFile = filePath;
     const content = fs.readFileSync(filePath, 'utf-8');
     console.log('[MAIN] File read successfully, content length:', content.length);
+    console.log('[MAIN] About to send file-opened. mainWindow:', !!mainWindow, 'webContents:', !!(mainWindow?.webContents), 'rendererReady:', rendererReady);
     if (mainWindow && mainWindow.webContents && rendererReady) {
       // Send file immediately - renderer-ready means UI is initialized
       console.log('[MAIN] Sending file-opened to renderer');

src/renderer.js

@@ -230,7 +230,7 @@ class TabManager {
             editorView: null,
             findMatches: [],
             currentMatchIndex: -1,
-            type: type,
+            type: type, // 'markdown' or 'pdf'
             // PDF-specific state
             pdfDoc: null,
             pdfCurrentPage: 1,
@@ -243,6 +243,7 @@ class TabManager {
         this.switchToTab(newTabId);
         this.startAutoSave();
         this.updateTabBar();
+        console.log('createNewTab: tab created with type:', type);
     }
 
     createPdfTab(filePath) {
@@ -1331,6 +1332,7 @@ class TabManager {
     openFile(filePath, content) {
         console.log('openFile called with:', filePath, 'content length:', content.length);
         let tab = this.tabs.get(this.activeTabId);
+        console.log('openFile tab state before:', { id: tab?.id, hasEditorView: !!tab?.editorView, contentLength: tab?.content?.length, filePath: tab?.filePath, isDirty: tab?.isDirty });
 
         // Handle both forward and back slashes for cross-platform compatibility
         const fileName = filePath.split(/[\\/]/).pop();
@@ -1346,6 +1348,7 @@ class TabManager {
 
             // Update the editor and preview
             this.setEditorContent(this.activeTabId, content);
+            console.log('openFile after setEditorContent, tab state:', { id: tab.id, hasEditorView: !!tab.editorView, contentLength: tab.content.length });
             this.updatePreview(this.activeTabId);
             this.updateWordCount();
         } else {
@@ -1353,6 +1356,7 @@ class TabManager {
             console.log('Creating new tab for file');
             this.createNewTab();
             tab = this.tabs.get(this.activeTabId);
+            console.log('openFile after createNewTab, tab:', { id: tab.id, hasEditorView: !!tab.editorView });
             tab.filePath = filePath;
             tab.title = fileName;
             tab.content = content;
@@ -1361,6 +1365,7 @@ class TabManager {
 
             // Set content in the CodeMirror editor
             this.setEditorContent(this.activeTabId, content);
+            console.log('openFile after setEditorContent, tab state:', { id: tab.id, hasEditorView: !!tab.editorView, contentLength: tab.content.length });
             this.updatePreview(this.activeTabId);
             this.updateWordCount();
         }
@@ -1369,6 +1374,7 @@ class TabManager {
         this.updateTabBar();
         this.updateFilePath();
         this.updateBreadcrumb();
+        this.updateUI(); // Ensure tab content is visible
 
         // Notify main process about current file for exports
         ipcRenderer.send('set-current-file', filePath);
@@ -1835,6 +1841,7 @@ document.addEventListener('DOMContentLoaded', async () => {
     }, 30000);
 });
 
+// IPC event listeners
 // IPC event listeners
 ipcRenderer.on('file-new', () => {
     tabManager.createNewTab();
@@ -1842,8 +1849,20 @@ ipcRenderer.on('file-new', () => {
 
 ipcRenderer.on('file-opened', (event, data) => {
     console.log('[RENDERER] file-opened received:', data.path, 'content length:', data.content.length);
+    console.log('[RENDERER] activeTabId before openFile:', tabManager.activeTabId);
+    // Diagnostic: check library state
+    console.log('[RENDERER] Library state:', {
+        marked: typeof marked,
+        DOMPurify: typeof DOMPurify,
+        markedParse: typeof marked?.parse,
+        dompurifySanitize: typeof DOMPurify?.sanitize,
+        tabManagerExists: !!tabManager
+    });
     if (tabManager) {
         tabManager.openFile(data.path, data.content);
+        console.log('[RENDERER] activeTabId after openFile:', tabManager.activeTabId);
+        const tab = tabManager.tabs.get(tabManager.activeTabId);
+        console.log('[RENDERER] tab state:', { id: tab?.id, hasEditorView: !!tab?.editorView, contentLength: tab?.content?.length });
     } else {
         console.error('[RENDERER] tabManager not initialized!');
     }