Show working diffs with context like Zed

Author: bohutang

packages/desktop/src/features/git/DiffManager.ts

@@ -37,6 +37,7 @@ export type WorkingTreeGroups = {
 const MAX_UNTRACKED_FILE_BYTES = 1024 * 1024; // 1MB
 
 export class GitDiffManager {
+  private readonly WORKING_DIFF_CONTEXT_LINES = 3; // Zed/Git default context
   constructor(
     private gitExecutor: GitExecutor,
     private logger?: Logger,
@@ -190,7 +191,7 @@ export class GitDiffManager {
     const { stdout: trackedDiff } = await this.runGit({
       sessionId,
       cwd: worktreePath,
-      argv: ['git', 'diff', '--color=never', '--unified=0', '--src-prefix=a/', '--dst-prefix=b/', 'HEAD'],
+      argv: ['git', 'diff', '--color=never', `--unified=${this.WORKING_DIFF_CONTEXT_LINES}`, '--src-prefix=a/', '--dst-prefix=b/', 'HEAD'],
       timeoutMs: 120_000,
       meta: { source: 'gitDiff', operation: 'diff-working' },
     });
@@ -238,7 +239,7 @@ export class GitDiffManager {
       const { stdout: diff } = await this.runGit({
         sessionId,
         cwd: worktreePath,
-        argv: ['git', 'diff', '--cached', '--color=never', '--unified=0', '--src-prefix=a/', '--dst-prefix=b/', 'HEAD'],
+        argv: ['git', 'diff', '--cached', '--color=never', `--unified=${this.WORKING_DIFF_CONTEXT_LINES}`, '--src-prefix=a/', '--dst-prefix=b/', 'HEAD'],
         timeoutMs: 120_000,
         meta: { source: 'gitDiff', operation: 'diff-working-staged' },
       });
@@ -270,7 +271,7 @@ export class GitDiffManager {
       const { stdout: diff } = await this.runGit({
         sessionId,
         cwd: worktreePath,
-        argv: ['git', 'diff', '--color=never', '--unified=0', '--src-prefix=a/', '--dst-prefix=b/'],
+        argv: ['git', 'diff', '--color=never', `--unified=${this.WORKING_DIFF_CONTEXT_LINES}`, '--src-prefix=a/', '--dst-prefix=b/'],
         timeoutMs: 120_000,
         meta: { source: 'gitDiff', operation: 'diff-working-unstaged' },
       });

packages/desktop/src/features/git/StagingManager.ts

@@ -310,10 +310,11 @@ export class GitStagingManager {
     scope: 'staged' | 'unstaged',
     sessionId: string
   ): Promise<string> {
+    const unified = '--unified=3';
     const argv =
       scope === 'staged'
-        ? ['git', 'diff', '--cached', '--color=never', '--unified=0', '--src-prefix=a/', '--dst-prefix=b/', 'HEAD', '--', filePath]
-        : ['git', 'diff', '--color=never', '--unified=0', '--src-prefix=a/', '--dst-prefix=b/', '--', filePath];
+        ? ['git', 'diff', '--cached', '--color=never', unified, '--src-prefix=a/', '--dst-prefix=b/', 'HEAD', '--', filePath]
+        : ['git', 'diff', '--color=never', unified, '--src-prefix=a/', '--dst-prefix=b/', '--', filePath];
 
     const result = await this.gitExecutor.run({
       sessionId,

packages/desktop/src/features/git/__tests__/DiffManager.test.ts

@@ -3,7 +3,7 @@ import { GitDiffManager } from '../DiffManager';
 import type { GitExecutor } from '../../../executors/git';
 
 describe('GitDiffManager', () => {
-  it('uses --unified=0 for staged working tree diff', async () => {
+  it('uses --unified=3 for staged working tree diff', async () => {
     const mockGitExecutor: GitExecutor = {
       run: vi.fn(async ({ argv }) => {
         if (argv[1] === 'rev-parse') {
@@ -34,7 +34,7 @@ describe('GitDiffManager', () => {
       .mock.calls.find((c) => (c[0] as any).argv?.[1] === 'diff' && (c[0] as any).argv?.includes('--cached') && !(c[0] as any).argv?.includes('--name-only') && !(c[0] as any).argv?.includes('--shortstat'));
 
     expect(diffCall).toBeTruthy();
-    expect((diffCall?.[0] as any).argv).toEqual(expect.arrayContaining(['--unified=0']));
+    expect((diffCall?.[0] as any).argv).toEqual(expect.arrayContaining(['--unified=3']));
   });
 
   it('uses --unified=0 for commit diff (git show)', async () => {
@@ -64,4 +64,3 @@ describe('GitDiffManager', () => {
     expect((showCall?.[0] as any).argv).toEqual(expect.arrayContaining(['--unified=0']));
   });
 });
-

packages/desktop/src/features/git/__tests__/StagingManager.test.ts

@@ -334,7 +334,7 @@ describe('GitStagingManager', () => {
 
       // Verify git diff was called
       expect(mockGitExecutor.run).toHaveBeenNthCalledWith(1, expect.objectContaining({
-        argv: expect.arrayContaining(['git', 'diff', '--unified=0']),
+        argv: expect.arrayContaining(['git', 'diff', '--unified=3']),
       }));
 
       // Verify git apply was called with --cached
@@ -683,7 +683,7 @@ Binary files differ`;
       expect(mockGitExecutor.run).toHaveBeenCalledTimes(2);
 
       expect(mockGitExecutor.run).toHaveBeenNthCalledWith(1, expect.objectContaining({
-        argv: expect.arrayContaining(['git', 'diff', '--cached', '--unified=0']),
+        argv: expect.arrayContaining(['git', 'diff', '--cached', '--unified=3']),
       }));
 
       expect(mockGitExecutor.run).toHaveBeenNthCalledWith(2, expect.objectContaining({
@@ -728,7 +728,7 @@ Binary files differ`;
       expect(result.success).toBe(true);
       expect(mockGitExecutor.run).toHaveBeenCalledTimes(2);
       expect(mockGitExecutor.run).toHaveBeenNthCalledWith(1, expect.objectContaining({
-        argv: expect.arrayContaining(['git', 'diff', '--unified=0']),
+        argv: expect.arrayContaining(['git', 'diff', '--unified=3']),
       }));
       expect(mockGitExecutor.run).toHaveBeenNthCalledWith(2, expect.objectContaining({
         argv: expect.arrayContaining(['git', 'apply', '-R']),
@@ -779,7 +779,7 @@ Binary files differ`;
       expect(result.success).toBe(true);
       expect(mockGitExecutor.run).toHaveBeenCalledTimes(3);
       expect(mockGitExecutor.run).toHaveBeenNthCalledWith(1, expect.objectContaining({
-        argv: expect.arrayContaining(['git', 'diff', '--cached', '--unified=0']),
+        argv: expect.arrayContaining(['git', 'diff', '--cached', '--unified=3']),
       }));
       expect(mockGitExecutor.run).toHaveBeenNthCalledWith(2, expect.objectContaining({
         argv: expect.arrayContaining(['git', 'apply', '--cached', '-R']),