fix(core): resolve nested plan directory duplication and relative path policies (#25138)

packages/core/src/prompts/promptProvider.test.ts

@@ -7,6 +7,7 @@
 import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
 import { PromptProvider } from './promptProvider.js';
 import type { Config } from '../config/config.js';
+import { makeRelative } from '../utils/paths.js';
 import {
   getAllGeminiMdFilenames,
   DEFAULT_CONTEXT_FILENAME,
@@ -58,6 +59,7 @@ describe('PromptProvider', () => {
         ).getToolRegistry?.() as unknown as ToolRegistry;
       },
       getToolRegistry: vi.fn().mockReturnValue(mockToolRegistry),
+      getProjectRoot: vi.fn().mockReturnValue('/tmp/project-temp'),
       topicState: new TopicState(),
       getEnableShellOutputEfficiency: vi.fn().mockReturnValue(true),
       getSandboxEnabled: vi.fn().mockReturnValue(false),
@@ -236,7 +238,14 @@ describe('PromptProvider', () => {
       expect(prompt).toContain(
         '`write_file` and `replace` may ONLY be used to write .md plan files',
       );
-      expect(prompt).toContain('/tmp/project-temp/plans/');
+
+      const expectedRelativePath = makeRelative(
+        mockConfig.storage.getPlansDir(),
+        mockConfig.getProjectRoot(),
+      ).replaceAll('\\', '/');
+      expect(prompt).toContain(
+        `write .md plan files to \`${expectedRelativePath}/\``,
+      );
     });
   });
 

packages/core/src/prompts/promptProvider.ts

@@ -8,7 +8,7 @@ import fs from 'node:fs';
 import path from 'node:path';
 import process from 'node:process';
 import type { HierarchicalMemory } from '../config/memory.js';
-import { GEMINI_DIR } from '../utils/paths.js';
+import { GEMINI_DIR, makeRelative } from '../utils/paths.js';
 import { ApprovalMode } from '../policy/types.js';
 import * as snippets from './snippets.js';
 import * as legacySnippets from './snippets.legacy.js';
@@ -199,8 +199,19 @@ export class PromptProvider {
           () => ({
             interactive: interactiveMode,
             planModeToolsList,
-            plansDir: context.config.storage.getPlansDir(),
-            approvedPlanPath: context.config.getApprovedPlanPath(),
+            plansDir: makeRelative(
+              context.config.storage.getPlansDir(),
+              context.config.getProjectRoot(),
+            ).replaceAll('\\', '/'),
+            approvedPlanPath: (() => {
+              const approvedPath = context.config.getApprovedPlanPath();
+              return approvedPath
+                ? makeRelative(
+                    approvedPath,
+                    context.config.getProjectRoot(),
+                  ).replaceAll('\\', '/')
+                : undefined;
+            })(),
           }),
           isPlanMode,
         ),