feat(git): inline file diffs in commit history rows (#1291)

* chore: add .worktrees/ to gitignore for worktree workflow

* feat(git): add getCommitFileDiff service function

* docs(git): document getCommitFileDiff in module docs

* feat(git): add GET /api/git/commit-file-diff route

* feat(git): add CommitFileDiffResponse type and GitAPI method signature

* feat(git): add getCommitFileDiff HTTP client function

* feat(git): add getCommitFileDiff API facade

* feat(git): add getCommitFileDiff stub to VS Code bridge

* feat(git): add getCommitFileDiff to VS Code gitService and bridge handler

* feat(git): add inline file diff to history commit rows

* fix(git): consolidate CommitFileDiffResponse import to gitApi facade

* fix(git): pass directory through history, validate hash, propagate git errors

* fix(git): use exit code check for VS Code getCommitFileDiff error detection

* fix(git): VS Code rename detection, hash validation parity, retry on error

* fix(git): register scroll container as virtualizer root to fix empty space in history diffs

* fix(git): address greptile review — rename key extraction, directory guard, language detection, isBinary cleanup

* fix(git): harden history inline diffs

---------

Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>

packages/web/server/lib/git/DOCUMENTATION.md

@@ -58,6 +58,7 @@ The following functions are exported and used by the web server:
 ### Log Operations
 - `getLog(directory, options)`: Get commit history with stats (supports maxCount, from, to, file filters).
 - `getCommitFiles(directory, commitHash)`: Get file changes for a specific commit.
+- `getCommitFileDiff(directory, hash, filePath, isBinary)`: Get before/after content for a specific file in a commit. Returns `{ original, modified, isBinary }`. Runs `git show <hash>^:<path>` and `git show <hash>:<path>` in parallel; returns empty strings on failure (added/deleted/root-commit edge cases).
 
 ### Merge and Rebase Operations
 - `rebase(directory, options)`: Start a rebase onto a target branch.

packages/web/server/lib/git/routes.js

@@ -943,4 +943,30 @@ export function registerGitRoutes(app) {
     }
   });
 
+  app.get('/api/git/commit-file-diff', async (req, res) => {
+    const { getCommitFileDiff } = await getGitLibraries();
+    try {
+      const { directory, hash, path: filePath } = req.query;
+      if (!directory || typeof directory !== 'string') {
+        return res.status(400).json({ error: 'directory parameter is required' });
+      }
+      if (!hash || typeof hash !== 'string') {
+        return res.status(400).json({ error: 'hash parameter is required' });
+      }
+      if (!/^[0-9a-fA-F]{7,40}$/.test(hash)) {
+        return res.status(400).json({ error: 'hash must be a valid commit SHA' });
+      }
+      if (!filePath || typeof filePath !== 'string') {
+        return res.status(400).json({ error: 'path parameter is required' });
+      }
+
+      const isBinary = req.query.binary === 'true';
+      const result = await getCommitFileDiff(directory, hash, filePath, isBinary);
+      res.json(result);
+    } catch (error) {
+      console.error('Failed to get commit file diff:', error);
+      res.status(500).json({ error: error.message || 'Failed to get commit file diff' });
+    }
+  });
+
 }

packages/web/server/lib/git/service.js

@@ -1611,6 +1611,27 @@ const parseIsBinaryFromNumstat = (raw) => {
   return added === '-' || deleted === '-';
 };
 
+const extractGitStatusPath = (status, pathPart) => {
+  if ((status === 'R' || status === 'C') && pathPart.includes('\t')) {
+    return pathPart.split('\t').pop() || pathPart;
+  }
+  return pathPart;
+};
+
+const extractGitNumstatDestinationPath = (filePath) => {
+  if (!filePath.includes(' => ')) {
+    return filePath;
+  }
+
+  const braceMatch = filePath.match(/^(.*)\{([^{}]*)\s=>\s([^{}]*)\}(.*)$/);
+  if (braceMatch) {
+    const [, prefix, , destination, suffix] = braceMatch;
+    return `${prefix}${destination}${suffix}`.replace(/\/+/g, '/');
+  }
+
+  return filePath.split(' => ').pop()?.trim() || filePath;
+};
+
 const looksBinaryBySniff = async (absolutePath) => {
   try {
     const handle = await fsp.open(absolutePath, 'r');
@@ -3028,15 +3049,13 @@ export async function getCommitFiles(directory, commitHash) {
     for (const line of statusLines) {
       const match = line.match(/^([AMDRC])\d*\t(.+)$/);
       if (match) {
-        const [, status, path] = match;
-        statusMap.set(path, status);
+        const [, status, pathPart] = match;
+        statusMap.set(extractGitStatusPath(status, pathPart), status);
       }
     }
 
     for (const file of files) {
-      const basePath = file.path.includes(' => ')
-        ? file.path.split(' => ').pop()?.replace(/[{}]/g, '') || file.path
-        : file.path;
+      const basePath = extractGitNumstatDestinationPath(file.path);
 
       const status = statusMap.get(basePath) || statusMap.get(file.path);
       if (status) {
@@ -3379,3 +3398,29 @@ export async function getConflictDetails(directory) {
     throw error;
   }
 }
+
+export async function getCommitFileDiff(directory, hash, filePath, isBinary) {
+  if (!directory || !hash || !filePath) {
+    throw new Error('directory, hash, and path are required for getCommitFileDiff');
+  }
+
+  if (isBinary) {
+    return { original: '', modified: '', isBinary: true };
+  }
+
+  const directoryPath = normalizeDirectoryPath(directory);
+
+  const [originalResult, modifiedResult] = await Promise.all([
+    runGitCommand(directoryPath, ['show', `${hash}^:${filePath}`]),
+    runGitCommand(directoryPath, ['show', `${hash}:${filePath}`]),
+  ]);
+
+  const original = originalResult.success ? originalResult.stdout : '';
+  const modified = modifiedResult.success ? modifiedResult.stdout : '';
+
+  if (!originalResult.success && !modifiedResult.success) {
+    throw new Error(`Failed to read file content at commit ${hash}: ${originalResult.stderr || modifiedResult.stderr}`);
+  }
+
+  return { original, modified, isBinary: false };
+}