fix: Address code review comments

apps/server/src/services/cherry-pick-service.ts

@@ -0,0 +1,162 @@
+/**
+ * CherryPickService - Cherry-pick git operations without HTTP
+ *
+ * Extracted from worktree cherry-pick route to encapsulate all git
+ * cherry-pick business logic in a single service. Follows the same
+ * pattern as merge-service.ts.
+ */
+
+import { createLogger } from '@automaker/utils';
+import { spawnProcess } from '@automaker/platform';
+
+const logger = createLogger('CherryPickService');
+
+// ============================================================================
+// Types
+// ============================================================================
+
+export interface CherryPickOptions {
+  noCommit?: boolean;
+}
+
+export interface CherryPickResult {
+  success: boolean;
+  error?: string;
+  hasConflicts?: boolean;
+  aborted?: boolean;
+  cherryPicked?: boolean;
+  commitHashes?: string[];
+  branch?: string;
+  message?: string;
+}
+
+// ============================================================================
+// Internal git command execution
+// ============================================================================
+
+/**
+ * Execute git command with array arguments to prevent command injection.
+ */
+async function execGitCommand(args: string[], cwd: string): Promise<string> {
+  const result = await spawnProcess({
+    command: 'git',
+    args,
+    cwd,
+  });
+
+  if (result.exitCode === 0) {
+    return result.stdout;
+  } else {
+    const errorMessage = result.stderr || `Git command failed with code ${result.exitCode}`;
+    throw new Error(errorMessage);
+  }
+}
+
+// ============================================================================
+// Service Functions
+// ============================================================================
+
+/**
+ * Verify that each commit hash exists in the repository.
+ *
+ * @param worktreePath - Path to the git worktree
+ * @param commitHashes - Array of commit hashes to verify
+ * @returns The first invalid commit hash, or null if all are valid
+ */
+export async function verifyCommits(
+  worktreePath: string,
+  commitHashes: string[]
+): Promise<string | null> {
+  for (const hash of commitHashes) {
+    try {
+      await execGitCommand(['rev-parse', '--verify', hash], worktreePath);
+    } catch {
+      return hash;
+    }
+  }
+  return null;
+}
+
+/**
+ * Run the cherry-pick operation on the given worktree.
+ *
+ * @param worktreePath - Path to the git worktree
+ * @param commitHashes - Array of commit hashes to cherry-pick (in order)
+ * @param options - Cherry-pick options (e.g., noCommit)
+ * @returns CherryPickResult with success/failure information
+ */
+export async function runCherryPick(
+  worktreePath: string,
+  commitHashes: string[],
+  options?: CherryPickOptions
+): Promise<CherryPickResult> {
+  const args = ['cherry-pick'];
+  if (options?.noCommit) {
+    args.push('--no-commit');
+  }
+  args.push(...commitHashes);
+
+  try {
+    await execGitCommand(args, worktreePath);
+
+    const branch = await getCurrentBranch(worktreePath);
+
+    return {
+      success: true,
+      cherryPicked: true,
+      commitHashes,
+      branch,
+      message: `Successfully cherry-picked ${commitHashes.length} commit(s)`,
+    };
+  } catch (cherryPickError: unknown) {
+    // Check if this is a cherry-pick conflict
+    const err = cherryPickError as { stdout?: string; stderr?: string; message?: string };
+    const output = `${err.stdout || ''} ${err.stderr || ''} ${err.message || ''}`;
+    const hasConflicts =
+      output.includes('CONFLICT') ||
+      output.includes('cherry-pick failed') ||
+      output.includes('could not apply');
+
+    if (hasConflicts) {
+      // Abort the cherry-pick to leave the repo in a clean state
+      await abortCherryPick(worktreePath);
+
+      return {
+        success: false,
+        error: 'Cherry-pick aborted due to conflicts; no changes were applied.',
+        hasConflicts: true,
+        aborted: true,
+      };
+    }
+
+    // Non-conflict error - propagate
+    throw cherryPickError;
+  }
+}
+
+/**
+ * Abort an in-progress cherry-pick operation.
+ *
+ * @param worktreePath - Path to the git worktree
+ * @returns true if abort succeeded, false if it failed (logged as warning)
+ */
+export async function abortCherryPick(worktreePath: string): Promise<boolean> {
+  try {
+    await execGitCommand(['cherry-pick', '--abort'], worktreePath);
+    return true;
+  } catch {
+    logger.warn('Failed to abort cherry-pick after conflict');
+    return false;
+  }
+}
+
+/**
+ * Get the current branch name for the worktree.
+ *
+ * @param worktreePath - Path to the git worktree
+ * @returns The current branch name
+ */
+export async function getCurrentBranch(worktreePath: string): Promise<string> {
+  const branchOutput = await execGitCommand(['rev-parse', '--abbrev-ref', 'HEAD'], worktreePath);
+  return branchOutput.trim();
+}