test: add unit tests for src/git/diff.ts

src/commands/suggest.ts

@@ -147,7 +147,7 @@ async function acceptAndCommit(selected: Suggestion, config: Config, diff: strin
   if (auto) {
     try {
       const result = commit(selected.message, selected.body);
-      console.log(pc.green(result.trim()));
+      console.log(pc.green(result.summary));
     } catch (err) {
       const msg = err instanceof Error ? err.message : 'Unknown error';
       outro(pc.red(`Commit failed: ${msg}`));
@@ -208,7 +208,7 @@ async function acceptAndCommit(selected: Suggestion, config: Config, diff: strin
 
   try {
     const result = commit(finalMessage, finalBody);
-    console.log(pc.green(result.trim()));
+    console.log(pc.green(result.summary));
 
     await appendEntry({
       timestamp: new Date().toISOString(),

src/git/diff.ts

@@ -1,14 +1,22 @@
 import { execSync, spawnSync } from 'node:child_process';
 import { writeFileSync, unlinkSync } from 'node:fs';
 import { tmpdir } from 'node:os';
-import { join } from 'node:path';
+import { join, normalize } from 'node:path';
 
 export interface DiffResult {
   diff: string;
   hasChanges: boolean;
   staged: boolean;
 }
 
+export interface CommitResult {
+  hash: string;
+  summary: string;
+  output: string;
+}
+
+const GIT_DIFF_MAX_BUFFER = 100 * 1024 * 1024;
+
 export function checkGitRepo(): void {
   try {
     execSync('git rev-parse --git-dir', { encoding: 'utf-8', stdio: 'pipe' });
@@ -18,8 +26,24 @@ export function checkGitRepo(): void {
   }
 }
 
+export function hasCommits(): boolean {
+  try {
+    const count = execSync('git rev-list --count HEAD', {
+      encoding: 'utf-8',
+      stdio: 'pipe',
+    }).trim();
+
+    return Number.parseInt(count, 10) > 0;
+  } catch {
+    return false;
+  }
+}
+
 export function getStagedDiff(): DiffResult {
-  const diff = execSync('git diff --cached', { encoding: 'utf-8' });
+  const diff = execSync('git diff --cached', {
+    encoding: 'utf-8',
+    maxBuffer: GIT_DIFF_MAX_BUFFER,
+  });
   return {
     diff: diff.trim(),
     hasChanges: diff.trim().length > 0,
@@ -28,16 +52,29 @@ export function getStagedDiff(): DiffResult {
 }
 
 export function getUnstagedDiff(): DiffResult {
-  const diff = execSync('git diff', { encoding: 'utf-8' });
+  const diff = execSync('git diff', {
+    encoding: 'utf-8',
+    maxBuffer: GIT_DIFF_MAX_BUFFER,
+  });
   return {
     diff: diff.trim(),
     hasChanges: diff.trim().length > 0,
     staged: false,
   };
 }
 
+function parseCommitOutput(output: string): CommitResult {
+  const summary = output.trim().split('\n').find(Boolean) ?? '';
+  const match = summary.match(/^\[(?:.+\s)?([a-f0-9]{7,})\]\s+(.+)$/i);
 
-export function commit(message: string, body?: string): string {
+  return {
+    hash: match?.[1] ?? '',
+    summary: match?.[2] ?? summary,
+    output,
+  };
+}
+
+export function commit(message: string, body?: string): CommitResult {
   const fullMessage = body ? `${message}\n\n${body}` : message;
   const tmpFile = join(tmpdir(), `commit-echo-msg-${process.pid}-${Date.now()}.txt`);
   try {
@@ -51,12 +88,30 @@ export function commit(message: string, body?: string): string {
       const detail = [result.stderr, result.stdout].filter(Boolean).join('\n').trim();
       throw new Error(detail || `git commit exited with code ${result.status}`);
     }
-    return result.stdout;
+    return parseCommitOutput(result.stdout);
   } finally {
-    try { unlinkSync(tmpFile); } catch {}
+    try {
+      unlinkSync(tmpFile);
+    } catch {}
   }
 }
 
 export function getRepoRoot(): string {
-  return execSync('git rev-parse --show-toplevel', { encoding: 'utf-8' }).trim();
+  return normalize(execSync('git rev-parse --show-toplevel', { encoding: 'utf-8' }).trim());
+}
+
+export function getBranchName(): string {
+  try {
+    return execSync('git rev-parse --abbrev-ref HEAD', { encoding: 'utf-8' }).trim();
+  } catch {
+    return 'unknown';
+  }
+}
+
+export function getLastCommitMessage(): string {
+  try {
+    return execSync('git log -1 --format=%s', { encoding: 'utf-8', stdio: 'pipe' }).trim();
+  } catch {
+    return '';
+  }
 }