[ide-mode] Thread active file through to system prompt (#4264)

4 files changed, 56 insertions, 18 deletions

diff --git a/packages/core/src/core/client.test.ts b/packages/core/src/core/client.test.ts
index 03793bda..1f9d4e31 100644
--- a/packages/core/src/core/client.test.ts
+++ b/packages/core/src/core/client.test.ts
@@ -346,7 +346,7 @@ describe('Gemini Client (client.ts)', () => {
         model: 'test-model',
         config: {
           abortSignal,
-          systemInstruction: getCoreSystemPrompt(''),
+          systemInstruction: getCoreSystemPrompt(client['config'], ''),
           temperature: 0.5,
           topP: 1,
         },
@@ -374,7 +374,7 @@ describe('Gemini Client (client.ts)', () => {
         model: 'test-model', // Should use current model from config
         config: {
           abortSignal,
-          systemInstruction: getCoreSystemPrompt(''),
+          systemInstruction: getCoreSystemPrompt(client['config'], ''),
           temperature: 0,
           topP: 1,
           responseSchema: schema,
@@ -409,7 +409,7 @@ describe('Gemini Client (client.ts)', () => {
         model: customModel,
         config: {
           abortSignal,
-          systemInstruction: getCoreSystemPrompt(''),
+          systemInstruction: getCoreSystemPrompt(client['config'], ''),
           temperature: 0.9,
           topP: 1, // from default
           topK: 20,
diff --git a/packages/core/src/core/client.ts b/packages/core/src/core/client.ts
index 80979812..1163a2f0 100644
--- a/packages/core/src/core/client.ts
+++ b/packages/core/src/core/client.ts
@@ -238,7 +238,7 @@ export class GeminiClient {
     ];
     try {
       const userMemory = this.config.getUserMemory();
-      const systemInstruction = getCoreSystemPrompt(userMemory);
+      const systemInstruction = getCoreSystemPrompt(this.config, userMemory);
       const generateContentConfigWithThinking = isThinkingSupported(
         this.config.getModel(),
       )
@@ -354,7 +354,7 @@ export class GeminiClient {
       model || this.config.getModel() || DEFAULT_GEMINI_FLASH_MODEL;
     try {
       const userMemory = this.config.getUserMemory();
-      const systemInstruction = getCoreSystemPrompt(userMemory);
+      const systemInstruction = getCoreSystemPrompt(this.config, userMemory);
       const requestConfig = {
         abortSignal,
         ...this.generateContentConfig,
@@ -447,7 +447,7 @@ export class GeminiClient {
 
     try {
       const userMemory = this.config.getUserMemory();
-      const systemInstruction = getCoreSystemPrompt(userMemory);
+      const systemInstruction = getCoreSystemPrompt(this.config, userMemory);
 
       const requestConfig = {
         abortSignal,
diff --git a/packages/core/src/core/prompts.test.ts b/packages/core/src/core/prompts.test.ts
index bb7b0b52..6a7f0f8a 100644
--- a/packages/core/src/core/prompts.test.ts
+++ b/packages/core/src/core/prompts.test.ts
@@ -4,9 +4,10 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { describe, it, expect, vi } from 'vitest';
+import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { getCoreSystemPrompt } from './prompts.js';
 import { isGitRepository } from '../utils/gitUtils.js';
+import { Config } from '../config/config.js';
 
 // Mock tool names if they are dynamically generated or complex
 vi.mock('../tools/ls', () => ({ LSTool: { Name: 'list_directory' } }));
@@ -26,11 +27,25 @@ vi.mock('../tools/write-file', () => ({
 vi.mock('../utils/gitUtils', () => ({
   isGitRepository: vi.fn(),
 }));
+vi.mock('../config/config.js');
 
 describe('Core System Prompt (prompts.ts)', () => {
+  let mockConfig: Config;
+
+  beforeEach(() => {
+    const MockedConfig = vi.mocked(Config, true);
+    MockedConfig.mockImplementation(() => {
+      const mock = {
+        getIdeMode: vi.fn().mockReturnValue(false),
+      };
+      return mock as unknown as Config;
+    });
+    mockConfig = new Config({} as never);
+  });
+
   it('should return the base prompt when no userMemory is provided', () => {
     vi.stubEnv('SANDBOX', undefined);
-    const prompt = getCoreSystemPrompt();
+    const prompt = getCoreSystemPrompt(mockConfig);
     expect(prompt).not.toContain('---\n\n'); // Separator should not be present
     expect(prompt).toContain('You are an interactive CLI agent'); // Check for core content
     expect(prompt).toMatchSnapshot(); // Use snapshot for base prompt structure
@@ -38,7 +53,7 @@ describe('Core System Prompt (prompts.ts)', () => {
 
   it('should return the base prompt when userMemory is empty string', () => {
     vi.stubEnv('SANDBOX', undefined);
-    const prompt = getCoreSystemPrompt('');
+    const prompt = getCoreSystemPrompt(mockConfig, '');
     expect(prompt).not.toContain('---\n\n');
     expect(prompt).toContain('You are an interactive CLI agent');
     expect(prompt).toMatchSnapshot();
@@ -46,7 +61,7 @@ describe('Core System Prompt (prompts.ts)', () => {
 
   it('should return the base prompt when userMemory is whitespace only', () => {
     vi.stubEnv('SANDBOX', undefined);
-    const prompt = getCoreSystemPrompt('   \n  \t ');
+    const prompt = getCoreSystemPrompt(mockConfig, '   \n  \t ');
     expect(prompt).not.toContain('---\n\n');
     expect(prompt).toContain('You are an interactive CLI agent');
     expect(prompt).toMatchSnapshot();
@@ -56,7 +71,7 @@ describe('Core System Prompt (prompts.ts)', () => {
     vi.stubEnv('SANDBOX', undefined);
     const memory = 'This is custom user memory.\nBe extra polite.';
     const expectedSuffix = `\n\n---\n\n${memory}`;
-    const prompt = getCoreSystemPrompt(memory);
+    const prompt = getCoreSystemPrompt(mockConfig, memory);
 
     expect(prompt.endsWith(expectedSuffix)).toBe(true);
     expect(prompt).toContain('You are an interactive CLI agent'); // Ensure base prompt follows
@@ -65,7 +80,7 @@ describe('Core System Prompt (prompts.ts)', () => {
 
   it('should include sandbox-specific instructions when SANDBOX env var is set', () => {
     vi.stubEnv('SANDBOX', 'true'); // Generic sandbox value
-    const prompt = getCoreSystemPrompt();
+    const prompt = getCoreSystemPrompt(mockConfig);
     expect(prompt).toContain('# Sandbox');
     expect(prompt).not.toContain('# MacOS Seatbelt');
     expect(prompt).not.toContain('# Outside of Sandbox');
@@ -74,7 +89,7 @@ describe('Core System Prompt (prompts.ts)', () => {
 
   it('should include seatbelt-specific instructions when SANDBOX env var is "sandbox-exec"', () => {
     vi.stubEnv('SANDBOX', 'sandbox-exec');
-    const prompt = getCoreSystemPrompt();
+    const prompt = getCoreSystemPrompt(mockConfig);
     expect(prompt).toContain('# MacOS Seatbelt');
     expect(prompt).not.toContain('# Sandbox');
     expect(prompt).not.toContain('# Outside of Sandbox');
@@ -83,7 +98,7 @@ describe('Core System Prompt (prompts.ts)', () => {
 
   it('should include non-sandbox instructions when SANDBOX env var is not set', () => {
     vi.stubEnv('SANDBOX', undefined); // Ensure it's not set
-    const prompt = getCoreSystemPrompt();
+    const prompt = getCoreSystemPrompt(mockConfig);
     expect(prompt).toContain('# Outside of Sandbox');
     expect(prompt).not.toContain('# Sandbox');
     expect(prompt).not.toContain('# MacOS Seatbelt');
@@ -93,7 +108,7 @@ describe('Core System Prompt (prompts.ts)', () => {
   it('should include git instructions when in a git repo', () => {
     vi.stubEnv('SANDBOX', undefined);
     vi.mocked(isGitRepository).mockReturnValue(true);
-    const prompt = getCoreSystemPrompt();
+    const prompt = getCoreSystemPrompt(mockConfig);
     expect(prompt).toContain('# Git Repository');
     expect(prompt).toMatchSnapshot();
   });
@@ -101,7 +116,7 @@ describe('Core System Prompt (prompts.ts)', () => {
   it('should not include git instructions when not in a git repo', () => {
     vi.stubEnv('SANDBOX', undefined);
     vi.mocked(isGitRepository).mockReturnValue(false);
-    const prompt = getCoreSystemPrompt();
+    const prompt = getCoreSystemPrompt(mockConfig);
     expect(prompt).not.toContain('# Git Repository');
     expect(prompt).toMatchSnapshot();
   });
diff --git a/packages/core/src/core/prompts.ts b/packages/core/src/core/prompts.ts
index 3b23f735..4a0c7c6c 100644
--- a/packages/core/src/core/prompts.ts
+++ b/packages/core/src/core/prompts.ts
@@ -17,8 +17,13 @@ import { WriteFileTool } from '../tools/write-file.js';
 import process from 'node:process';
 import { isGitRepository } from '../utils/gitUtils.js';
 import { MemoryTool, GEMINI_CONFIG_DIR } from '../tools/memoryTool.js';
+import { Config } from '../config/config.js';
+import { ideContext } from '../services/ideContext.js';
 
-export function getCoreSystemPrompt(userMemory?: string): string {
+export function getCoreSystemPrompt(
+  config: Config,
+  userMemory?: string,
+): string {
   // if GEMINI_SYSTEM_MD is set (and not 0|false), override system prompt from file
   // default path is .gemini/system.md but can be modified via custom path in GEMINI_SYSTEM_MD
   let systemMdEnabled = false;
@@ -153,7 +158,25 @@ ${(function () {
   }
   return '';
 })()}
-
+${(function () {
+  if (config.getIdeMode()) {
+    const activeFile = ideContext.getActiveFileContext();
+    if (activeFile?.filePath) {
+      let prompt = `
+# IDE Mode
+You are running in IDE mode. The user has the following file open:
+- Path: ${activeFile.filePath}`;
+      if (activeFile.cursor) {
+        prompt += `
+- Cursor Position: Line ${activeFile.cursor.line}, Character ${activeFile.cursor.character}`;
+      }
+      prompt += `
+Focus on providing contextually relevant assistance for this file.`;
+      return prompt;
+    }
+  }
+  return '';
+})()}
 # Examples (Illustrating Tone and Workflow)
 <example>
 user: 1 + 2