From e10154b5e4c6ac7ae9b5b393bb091ad798f266ad Mon Sep 17 00:00:00 2001
From: "A.K.M. Adib" <adibakm@google.com>
Date: Wed, 1 Apr 2026 10:03:24 -0400
Subject: [PATCH] refactor duplicated code

---
 packages/core/src/tools/exit-plan-mode.ts | 26 +++++++++--------------
 packages/core/src/utils/planUtils.ts      | 23 +++++++++++++++++++-
 2 files changed, 32 insertions(+), 17 deletions(-)

diff --git a/packages/core/src/tools/exit-plan-mode.ts b/packages/core/src/tools/exit-plan-mode.ts
index 3b50c70fe5..fb429b00cc 100644
--- a/packages/core/src/tools/exit-plan-mode.ts
+++ b/packages/core/src/tools/exit-plan-mode.ts
@@ -18,7 +18,11 @@ import type { MessageBus } from '../confirmation-bus/message-bus.js';
 import path from 'node:path';
 import type { Config } from '../config/config.js';
 import { EXIT_PLAN_MODE_TOOL_NAME } from './tool-names.js';
-import { validatePlanPath, validatePlanContent } from '../utils/planUtils.js';
+import {
+  validatePlanPath,
+  validatePlanContent,
+  getPlanVersions,
+} from '../utils/planUtils.js';
 import { ApprovalMode } from '../policy/types.js';
 import { resolveToRealPath, isSubpath } from '../utils/paths.js';
 import { logPlanExecution } from '../telemetry/loggers.js';
@@ -29,7 +33,6 @@ import { getPlanModeExitMessage } from '../utils/approvalModeUtils.js';
 import * as Diff from 'diff';
 import { DEFAULT_DIFF_OPTIONS } from './diffOptions.js';
 import { debugLogger } from '../utils/debugLogger.js';
-import * as fs from 'node:fs';
 import * as fsPromises from 'node:fs/promises';
 
 export interface ExitPlanModeParams {
@@ -160,12 +163,7 @@ export class ExitPlanModeInvocation extends BaseToolInvocation<
     // decision is 'ask_user'
     let diffContent: string | undefined;
     try {
-      const files = await fsPromises.readdir(path.dirname(resolvedPlanPath));
-      const base = path.basename(resolvedPlanPath);
-      const versions = files
-        .filter((f) => f.startsWith(`${base}.v`))
-        .map((f) => parseInt(f.slice(base.length + 2), 10))
-        .filter((v) => !isNaN(v));
+      const versions = await getPlanVersions(resolvedPlanPath);
       const latestVersion = versions.length > 0 ? Math.max(...versions) : 0;
 
       if (latestVersion > 0) {
@@ -270,14 +268,10 @@ Read and follow the plan strictly during implementation.`,
       };
     } else {
       try {
-        const files = await fsPromises.readdir(path.dirname(resolvedPlanPath));
-        const base = path.basename(resolvedPlanPath);
-        const versions = files
-          .filter((f) => f.startsWith(`${base}.v`))
-          .map((f) => parseInt(f.slice(base.length + 2), 10))
-          .filter((v) => !isNaN(v));
-        const nextVersion = (versions.length > 0 ? Math.max(...versions) : 0) + 1;
-        const backupPath = `${resolvedPlanPath}.v${nextVersion}`; 
+        const versions = await getPlanVersions(resolvedPlanPath);
+        const nextVersion =
+          (versions.length > 0 ? Math.max(...versions) : 0) + 1;
+        const backupPath = `${resolvedPlanPath}.v${nextVersion}`;
         const content = await fsPromises.readFile(resolvedPlanPath, 'utf8');
         await fsPromises.writeFile(backupPath, content, 'utf8');
       } catch (err) {
diff --git a/packages/core/src/utils/planUtils.ts b/packages/core/src/utils/planUtils.ts
index 559434b1e3..38a92847aa 100644
--- a/packages/core/src/utils/planUtils.ts
+++ b/packages/core/src/utils/planUtils.ts
@@ -5,8 +5,10 @@
  */
 
 import path from 'node:path';
+import fsPromises from 'node:fs/promises';
 import { isEmpty, fileExists } from './fileUtils.js';
 import { isSubpath, resolveToRealPath } from './paths.js';
+import { debugLogger } from './debugLogger.js';
 
 /**
  * Standard error messages for the plan approval workflow.
@@ -41,7 +43,6 @@ export async function validatePlanPath(
   if (!isSubpath(realPlansDir, realPath)) {
     return PlanErrorMessages.PATH_ACCESS_DENIED(planPath, realPlansDir);
   }
-
   if (!(await fileExists(resolvedPath))) {
     return PlanErrorMessages.FILE_NOT_FOUND(planPath);
   }
@@ -49,6 +50,26 @@ export async function validatePlanPath(
   return null;
 }
 
+/**
+ * Returns a list of version numbers for a plan file by scanning the directory.
+ * @param planPath The path to the plan file.
+ * @returns A promise that resolves to an array of version numbers.
+ */
+export async function getPlanVersions(planPath: string): Promise<number[]> {
+  const dir = path.dirname(planPath);
+  const base = path.basename(planPath);
+  try {
+    const files = await fsPromises.readdir(dir);
+    return files
+      .filter((f) => f.startsWith(`${base}.v`))
+      .map((f) => parseInt(f.slice(base.length + 2), 10))
+      .filter((v) => !isNaN(v));
+  } catch (err) {
+    debugLogger.error(`Failed to read plan versions in ${dir}:`, err);
+    return [];
+  }
+}
+
 /**
  * Validates that a plan file has non-empty content.
  * @param planPath The path to the plan file.