[FIX] Improve-diffs

package.json

@@ -87,6 +87,11 @@
           "default": true,
           "description": "Automatically strip outputs from cells with conflicts"
         },
+        "mergeNB.autoResolve.whitespace": {
+          "type": "boolean",
+          "default": true,
+          "description": "Automatically resolve conflicts when source differences are whitespace-only"
+        },
         "mergeNB.ui.showCellHeaders": {
           "type": "boolean",
           "default": false,
@@ -96,6 +101,11 @@
           "type": "boolean",
           "default": true,
           "description": "Enable Ctrl+Z / Ctrl+Shift+Z undo and redo shortcuts in the conflict resolution web UI"
+        },
+        "mergeNB.ui.showBaseColumn": {
+          "type": "boolean",
+          "default": false,
+          "description": "Show the base (common ancestor) branch column in the conflict resolution view. When false, only current and incoming columns are shown."
         }
       }
     }
@@ -151,4 +161,4 @@
     "markdown-it": "^14.1.0",
     "ws": "^8.19.0"
   }
-}
+}

src/conflictDetector.ts

@@ -19,6 +19,17 @@ import { matchCells, detectReordering } from './cellMatcher';
 import { parseNotebook } from './notebookParser';
 import { getSettings, MergeNBSettings } from './settings';
 
+function stripAllWhitespace(text: string): string {
+    return text.replace(/\r\n/g, '\n');
+}
+
+function isWhitespaceOnlyDifference(left: string, right: string): boolean {
+    if (left === right) return false;
+    const normalizeLines = (s: string) =>
+        s.replace(/\r\n/g, '\n').split('\n').map(l => l.trimEnd()).join('\n');
+    return normalizeLines(left) === normalizeLines(right);
+}
+
 /**
  * Result of auto-resolution preprocessing
  */
@@ -373,6 +384,38 @@ export function applyAutoResolutions(
             }
         }
 
+        // Auto-resolve whitespace-only differences when enabled
+        if (!autoResolved && effectiveSettings.autoResolveWhitespace) {
+            if (conflict.type === 'cell-modified') {
+                const currentSource = conflict.currentContent?.source;
+                const incomingSource = conflict.incomingContent?.source;
+
+                const currentSourceStr = Array.isArray(currentSource) ? currentSource.join('') : (currentSource || '');
+                const incomingSourceStr = Array.isArray(incomingSource) ? incomingSource.join('') : (incomingSource || '');
+
+                if (isWhitespaceOnlyDifference(currentSourceStr, incomingSourceStr)) {
+                    autoResolved = true;
+                    autoResolvedCount++;
+                    autoResolvedDescriptions.push(`Whitespace-only change resolved (cell ${(conflict.currentCellIndex ?? 0) + 1})`);
+                }
+            }
+
+            if (!autoResolved && conflict.type === 'cell-added' && conflict.currentContent && conflict.incomingContent) {
+                const currentSource = Array.isArray(conflict.currentContent.source)
+                    ? conflict.currentContent.source.join('')
+                    : conflict.currentContent.source;
+                const incomingSource = Array.isArray(conflict.incomingContent.source)
+                    ? conflict.incomingContent.source.join('')
+                    : conflict.incomingContent.source;
+
+                if (isWhitespaceOnlyDifference(currentSource, incomingSource)) {
+                    autoResolved = true;
+                    autoResolvedCount++;
+                    autoResolvedDescriptions.push(`Whitespace-only added cell resolved (cell ${(conflict.currentCellIndex ?? 0) + 1})`);
+                }
+            }
+        }
+
         if (!autoResolved) {
             remainingConflicts.push(conflict);
         }

src/resolver.ts

@@ -11,7 +11,7 @@
  * 6. Stages the resolved file in Git
  */
 
-import * as path from 'path';  
+import * as path from 'path';
 import * as vscode from 'vscode';
 import { detectSemanticConflicts, applyAutoResolutions, AutoResolveResult } from './conflictDetector';
 import { serializeNotebook, renumberExecutionCounts } from './notebookParser';
@@ -56,7 +56,7 @@ export interface ConflictedNotebook {
  * Main service for handling notebook merge conflict resolution.
  */
 export class NotebookConflictResolver {
-    constructor(private readonly extensionUri: vscode.Uri) {}
+    constructor(private readonly extensionUri: vscode.Uri) { }
 
     /**
      * Check if a file has semantic conflicts (Git UU status).
@@ -75,7 +75,7 @@ export class NotebookConflictResolver {
     async hasAnyConflicts(uri: vscode.Uri): Promise<ConflictedNotebook | null> {
         try {
             const isUnmerged = await gitIntegration.isUnmergedFile(uri.fsPath);
-            
+
             if (isUnmerged) {
                 return {
                     uri,
@@ -94,24 +94,24 @@ export class NotebookConflictResolver {
      */
     async findNotebooksWithConflicts(): Promise<ConflictedNotebook[]> {
         const withConflicts: ConflictedNotebook[] = [];
-        
+
         // Get unmerged files from Git status
         const unmergedFiles = await gitIntegration.getUnmergedFiles();
-        
+
         for (const file of unmergedFiles) {
             // Only process .ipynb files
             if (!file.path.endsWith('.ipynb')) {
                 continue;
             }
-            
+
             const uri = vscode.Uri.file(file.path);
-            
+
             withConflicts.push({
                 uri,
                 hasSemanticConflicts: true
             });
         }
-        
+
         return withConflicts;
     }
 
@@ -134,7 +134,7 @@ export class NotebookConflictResolver {
      */
     async resolveSemanticConflicts(uri: vscode.Uri): Promise<void> {
         const semanticConflict = await detectSemanticConflicts(uri.fsPath);
-        
+
         if (!semanticConflict) {
             vscode.window.showInformationMessage('No semantic conflicts detected.');
             return;
@@ -197,7 +197,8 @@ export class NotebookConflictResolver {
             semanticConflict: filteredSemanticConflict,
             autoResolveResult: autoResolveResult,
             hideNonConflictOutputs: settings.hideNonConflictOutputs,
-            enableUndoRedoHotkeys: settings.enableUndoRedoHotkeys
+            enableUndoRedoHotkeys: settings.enableUndoRedoHotkeys,
+            showBaseColumn: settings.showBaseColumn
         };
 
         const resolutionCallback = async (resolution: UnifiedResolution): Promise<void> => {
@@ -227,12 +228,12 @@ export class NotebookConflictResolver {
         }
 
         const resolvedRows = resolution.resolvedRows;
-        
+
         if (!resolvedRows || resolvedRows.length === 0) {
             // No resolutions provided
             if (autoResolveResult) {
                 let resolvedNotebook = autoResolveResult.resolvedNotebook;
-                
+
                 const renumber = await vscode.window.showQuickPick(
                     ['Yes', 'No'],
                     {
@@ -259,9 +260,9 @@ export class NotebookConflictResolver {
         }
 
         await this.applySemanticResolutionsFromRows(
-            uri, 
-            semanticConflict, 
-            resolvedRows, 
+            uri,
+            semanticConflict,
+            resolvedRows,
             resolution.markAsResolved,
             resolution.renumberExecutionCounts,
             autoResolveResult
@@ -320,7 +321,7 @@ export class NotebookConflictResolver {
 
         for (const row of rowsForResolution) {
             const { baseCell, currentCell, incomingCell, resolution: res } = row;
-            
+
             let cellToUse: NotebookCell | undefined;
 
             if (res) {
@@ -352,7 +353,7 @@ export class NotebookConflictResolver {
                     metadata: referenceCell?.metadata ? JSON.parse(JSON.stringify(referenceCell.metadata)) : {},
                     source: resolvedContent.split(/(?<=\n)/)
                 } as NotebookCell;
-                
+
                 if (cellType === 'code') {
                     (cellToUse as any).execution_count = null;
                     (cellToUse as any).outputs = [];
@@ -394,7 +395,7 @@ export class NotebookConflictResolver {
             markAsResolved,
             renumberExecutionCounts: shouldRenumber
         });
-        
+
         // Show success notification (non-blocking, fire and forget)
         vscode.window.showInformationMessage(
             `Resolved conflicts in ${path.basename(uri.fsPath)}`
@@ -408,12 +409,12 @@ export class NotebookConflictResolver {
         const content = serializeNotebook(notebook);
         const encoder = new TextEncoder();
         await vscode.workspace.fs.writeFile(uri, encoder.encode(content));
-        
+
         // Mark as resolved with git add if requested
         if (markAsResolved) {
             await this.markFileAsResolved(uri);
         }
-        
+
         // Fire event to notify extension (for status bar, decorations, etc.)
         onDidResolveConflict.fire(uri);
     }
@@ -433,7 +434,7 @@ export class NotebookConflictResolver {
                 vscode.window.showWarningMessage('Cannot mark file as resolved: not in a workspace');
                 return;
             }
-            
+
             const relativePath = vscode.workspace.asRelativePath(uri, false);
             await exec(`git add "${relativePath}"`, { cwd: workspaceFolder.uri.fsPath });
             vscode.window.showInformationMessage(`Marked ${relativePath} as resolved`);

src/settings.ts

@@ -6,8 +6,10 @@
  * - autoResolveExecutionCount: Set execution_count to null (default: true)
  * - autoResolveKernelVersion: Use current kernel/Python version (default: true)  
  * - stripOutputs: Clear cell outputs during merge (default: true)
+ * - autoResolveWhitespace: Auto-resolve whitespace-only source diffs (default: true)
  * - hideNonConflictOutputs: Hide outputs for non-conflicted cells in UI (default: true)
  * - enableUndoRedoHotkeys: Enable Ctrl+Z / Ctrl+Shift+Z in web UI (default: true)
+ * - showBaseColumn: Show base branch column in 3-column view (default: false, true in headless/testing)
  * 
  * These reduce manual conflict resolution for common non-semantic differences.
  */
@@ -24,17 +26,21 @@ export interface MergeNBSettings {
     autoResolveExecutionCount: boolean;
     autoResolveKernelVersion: boolean;
     stripOutputs: boolean;
+    autoResolveWhitespace: boolean;
     hideNonConflictOutputs: boolean;
     enableUndoRedoHotkeys: boolean;
+    showBaseColumn: boolean;
 }
 
 /** Default settings used in headless mode */
 const DEFAULT_SETTINGS: MergeNBSettings = {
     autoResolveExecutionCount: true,
     autoResolveKernelVersion: true,
     stripOutputs: true,
+    autoResolveWhitespace: true,
     hideNonConflictOutputs: true,
-    enableUndoRedoHotkeys: true
+    enableUndoRedoHotkeys: true,
+    showBaseColumn: true
 };
 
 /**
@@ -45,15 +51,17 @@ export function getSettings(): MergeNBSettings {
     if (!vscode) {
         return { ...DEFAULT_SETTINGS };
     }
-    
+
     const config = vscode.workspace.getConfiguration('mergeNB');
-    
+
     return {
         autoResolveExecutionCount: config.get<boolean>('autoResolve.executionCount', true),
         autoResolveKernelVersion: config.get<boolean>('autoResolve.kernelVersion', true),
         stripOutputs: config.get<boolean>('autoResolve.stripOutputs', true),
+        autoResolveWhitespace: config.get<boolean>('autoResolve.whitespace', true),
         hideNonConflictOutputs: config.get<boolean>('ui.hideNonConflictOutputs', true),
         enableUndoRedoHotkeys: config.get<boolean>('ui.enableUndoRedoHotkeys', true),
+        showBaseColumn: config.get<boolean>('ui.showBaseColumn', false),
     };
 }
 

src/tests/repoSetup.ts

@@ -44,6 +44,13 @@ export function createMergeConflictRepo(
 ): string {
     const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'mergeNB-integration-'));
 
+    const vscodeDir = path.join(tmpDir, '.vscode');
+    fs.mkdirSync(vscodeDir, { recursive: true });
+    const settingsPath = path.join(vscodeDir, 'settings.json');
+    fs.writeFileSync(settingsPath, JSON.stringify({
+        'mergeNB.ui.showBaseColumn': true
+    }, null, 4));
+
     git(tmpDir, 'init');
     git(tmpDir, 'config', 'user.email', '"test@mergenb.test"');
     git(tmpDir, 'config', 'user.name', '"MergeNB Test"');